28501488 a Review of Chitin and Chitosan Applications

8/12/2019 28501488 a Review of Chitin and Chitosan Applications

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Reactive & Functional Polymers 46 (2000) 127

www.elsevier.com/locate/react

Review

q review o! c"itin an# c"itosan a$$lications

%a'eti .. Ravi *umar+e$artment o! ,"emistry- niversity o! Rooree- Rooree 247 667- n#ia

Receive# 24 anuary 2000 receive# in revise# !orm 20 une 2000 acce$te# 23 une 2000

stract

,"itin is t"e most aun#ant natural amino $olysacc"ari#e an# is estimate# to e $ro#uce# annually almost as muc" ascellulose. t "as ecome o! 5reat interest not only as an un#erutilie# resource- ut also as a new !unctional material o! "i5"

$otential in various el#s- an# recent $ro5ress in c"itin c"emistry is 8uite notewort"y. 9"e $ur$ose o! t"is review is to tae acloser loo at c"itin an# c"itosan a$$lications. :ase# on current researc" an# e;istin5 $ro#ucts- some new an# !uturistica$$roac"es in t"is !ascinatin5 area are t"orou5"ly #iscusse#. 2000 =1GD1@314D(00)000GD@E


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2 ... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127

ra#aility- non@to;icity- a#sor$tion $ro$erties-etc.

Recently- muc" attention "as een $ai# to

c"itosan as a $otential $olysacc"ari#e resourceB3C. lt"ou5" several e!!orts "ave een re$orte#to $re$are !unctional #erivatives o! c"itosan yc"emical mo#ications B6DC- very !ew attaine#soluility in 5eneral or5anic solvents BE-10C an#some inary solvent systems B111GC. ,"emi@cally mo#ie# c"itin an# c"itosan structuresresultin5 in im$rove# soluility in 5eneral or@5anic solvents "ave een re$orte# y manyworers B142GC. 9"e $resent review is anattem$t to #iscuss t"e current a$$lications an#!uture $ros$ects o! c"itin an# c"itosan.

2. Processin5 o! c"itin an# c"itosan

,"itin is easily otaine# !rom cra or s"rim$s"ells an# !un5al mycelia. n t"e rst case-c"itin $ro#uction is associate# wit" !oo# in#us@Fi5. 1. =tructures o! cellulose- c"itin an# c"itosan.tries suc" as s"rim$ cannin5. n t"e secon# case-t"e $ro#uction o! c"itosan5lucan com$le;es is

c"itin- c"itosan an# t"eir #erivatives. ?owever- associate# wit" !ermentation $rocesses- similart"ese naturally aun#ant materials also e;"iit a to t"ose !or t"e $ro#uction o! citric aci# !romlimitation in t"eir reactivity an# $rocessaility s$er5illus ni5er- ucor rou;ii- an# =tre$@

BG-4C. n t"is res$ect- c"itin an# c"itosan are tomyces- w"ic" involves alali treatment yiel#@recommen#e# as suitale !unctional materials- in5 c"itosan5lucan com$le;es. 9"e alali re@ecause t"ese natural $olymers "ave e;cellent moves t"e $rotein an# #eacetylates c"itin simul@$ro$erties suc" as iocom$atiility- io#e5@ taneously. +e$en#in5 on t"e alali concentra@

=c"eme 1.


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... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127 G

tion- some solule 5lycans are remove# B24C. 4. Pro$erties o! c"itin an# c"itosan9"e $rocessin5 o! crustacean s"ells mainly

ost o! t"e naturally occurrin5 $olysac@involves t"e removal o! $roteins an# t"e #isso@c"ari#es- e.5. cellulose- #e;tran- $ectin- al5inic

lution o! calcium caronate w"ic" is $resent in aci#- a5ar- a5arose an# carra5enans- are neutralcra s"ells in "i5" concentrations. 9"e resultin5c"itin is #eacetylate# in 40 so#ium "y#ro;i#e or aci#ic in nature- w"ereas c"itin an# c"itosanat 120 8, !or 1G ". 9"is treatment $ro#uces are e;am$les o! "i5"ly asic $olysacc"ari#es.70 #eacetylate# c"itosan (=c"eme 1). 9"eir uni8ue $ro$erties inclu#e $olyo;ysalt

!ormation- aility to !orm lms- c"elate metalions an# o$tical structural c"aracteristics B2EC.

G.


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tives "ave een otaine# in met"anesul!onic t"e universally acce$te# non@to;ic @#e@aci# BGG-G4C. acetylate# #erivative o! c"itin- w"ere c"itin is

t room tem$erature- c"itosan !orms al@ @#eacetylate# to suc" an e;tent t"at it ecomes

#imines an# etimines wit" al#e"y#es an# solule in #ilute a8ueous acetic an# !ormicetones- res$ectively. Reaction wit" etoaci#s aci#s. n c"itin- t"e acetylate# units $revail!ollowe# y reaction wit" so#ium oro"y#ri#e (#e5ree o! acetylation ty$ically 0.E0). ,"itosan$ro#uces 5lucans carryin5 $roteic an# non@ is t"e !ully or $artially @#eacetylate# #erivative$roteic amino 5rou$s. @,aro;ymet"yl o! c"itin wit" a ty$ical #e5ree o! acetylation o!c"itosan is otaine# !rom 5lyo;ylic aci#.


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... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127 3

9ale 1

,"itin #erivatives an# t"eir $ro$ose# uses

+erivative


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4.1.G. =olvent an# solution $ro$erties t"e rst solutions o! c"itin t"at coul# e !orme#:ot" cellulose an# c"itin are "i5"ly crys@ into a ro$y@$lasticN state in 1E26. ?e $re$are#

talline- intractale materials an# only a limite# t"e solution usin5 inor5anic salts ca$ale o!

numer o! solvents are nown w"ic" are a$$lic@ stron5 "y#ration B4EC- suc" as Ai,=-ale as reaction solvents. ,"itin an# c"itosan ,a(,=) - ,a - ,a:r - ,a,l - etc. !ter t"is2 2 2 2

#e5ra#e e!ore meltin5- w"ic" is ty$ical !or re$ort- many solvent systems inclu#in5 or5anic$olysacc"ari#es wit" e;tensive "y#ro5en on#@ solvents an# mi;tures o! inor5anic salts an#in5. 9"is maes it necessary to #issolve c"itin or5anic solvents came into e;istence.an# c"itosan in an a$$ro$riate solvent system to 9o "el$ t"e #issolution o! c"itin- it was @im$art !unctionality. For eac" solvent system- #eacetylate# in 3 caustic so#a at 60 8, !or 14$olymer concentration- $?- counterion concen@ #ays B30C. not"er $roce#ure !or @#eacetyla@tration an# tem$erature e!!ects on t"e solution tion was to $lace t"e c"itin in an autoclave !or Gviscosity must e nown. ,om$arative #ata " at 1D0 8, an# 10 atm $ressure. t was $ointe#!rom solvent to solvent are not availale. s a out t"at 6 to 10 o! soli#s o! @#eacetylate#5eneral rule- t"e ma;imum amount o! $olymer c"itin can e rou5"t into aci#ic solution at

is #issolve# in a 5iven solvent towar#s a room tem$erature. 8ueous acetic aci# was"omo5eneous solution. =use8uently- t"e $oly@ !oun# to e suitale !or t"is $ur$ose.mer is re5enerate# in t"e re8uire# !orm (#is@ !ter $assin5 t"e $olymer solutions t"rou5" acusse# in t"e !ollowin5 sections). coa5ulant is lter $ress to remove im$urities- res werere8uire# !or $olymer re5eneration or soli#ica@ s$un. ,"emicals incom$atile wit" c"itin weretion. 9"e nature o! t"e coa5ulant is also "i5"ly su55este# as coa5ulants. 9"e resultant res#e$en#ent on t"e solvent an# solution $ro$erties were was"e# an# #rie# un#er tension. 9"e nalas well as t"e $olymer use# B34-73C. $ro#uct res "a# a roun#@ to "eart@s"a$e#

cross section wit" a tensile reain5 loa# o! G32

5/mm (G43 Pa). 9"e res $ossesse# a #ull3. ,"itin an# its #erivatives in re luster similar to natural sil- lea#in5 to t"e!ormation su55estion t"at t"e @#eacetylate# c"itin res

woul# mae 5oo# articial "air. 9"e collection3.1. atural microriller arran5ementan# recyclin5 o! c"itin !rom small@scale con@sumers was also su55este#. ,lar an# =mit","itin "as een nown to !orm microrillarre$orte# a $roce#ure !or $ro#ucin5 res yarran5ements in livin5 or5anisms. 9"ese rils#issolution o! c"itin at E3 8, in $resaturate#are usually eme##e# in a $rotein matri; an#solutions o! lit"ium t"iocyanate (saturate# 60 8,)"ave #iameters !rom 2.3 to 2.D nm. ,rustaceanB31C. o tensile $ro$erties or solution concen@cuticles $ossess c"itin microrils wit" #iame@trations were re$orte#. ?owever- Q@ray analysisters as lar5e as 23 nm. 9"e $resence o! mi@s"owe# a "i5" #e5ree o! orientation. =olventcrorils su55ests t"at c"itin "as c"aracteristicsremoval was not success!ul even at 200 8,.w"ic" mae it a 5oo# can#i#ate !or reAit"ium io#i#e was im$lie# to "ave e"ave# ins$innin5. 9o s$in c"itin or c"itosan res- t"et"e same manner. ratio o! 3 mol lit"ium

raw $olymer must e suitaly re#issolve# a!ter t"iocyanate $er mole an"y#ro5lucose unit wasremoval o! e;traneous material suc" as calcium!oun# to e;ist. 9"is is com$arale to t"ecaronate an# $roteins- w"ic" encase t"e mi@celluloselit"ium t"iocyanate com$oun#. ,[email protected] soluility an# t"e role o! solvate/saltcom$le;es "ave een reviewe# in #etail B32-3GC.3.2. Fire !ormation in retros$ectionRecently- Rat"e an# ?u#son $ulis"e# a re@

umerous met"o#s o! s$innin5 c"itin res view "i5"li5"tin5 t"e aility o! c"itin an#"ave een re$orte# since on Leimarn re$orte# c"itosan as re an# lm !ormers B34C.


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3.G. ovel solvent s$in systems su55este# as well as #issolution elow roomtem$erature. Fires were e;tru#e# t"rou5" a

3.G.1. ?alo5enate# solvent s$in system s$inneret o! 0.04 an# 0.06 mm #iameter into ann 1E73- ustin su55este# or5anic solvents

acetone coa5ulation at" !ollowe# y a met"a@containin5 aci#s !or t"e #irect #issolution o! nol at". 9"e tensile stren5t" o! #rie# lamentsc"itin. =uc" a system was c"loroet"anol an# was in t"e ran5e o! 1.67 to G.1 5/# wit" ansul!uric aci#. 9"e $reci$itation o! c"itin in elon5ation !rom D.7 to 20.0. 9"e stren5t" o!rillar !orm in water- met"anol- or a8ueous t"e res was im$rove# y leavin5 t"em in aammonium "y#ro;i#e was mentione#- ut no 0.3 5/l a8ueous caustic so#a solution !or 1 ".re tensile #ata were $resente# B33C. 9"e resultant tensile stren5t"s were 2.23 to G.20

n 1E73- :rine an# ustin su55este# tri@ 5/# wit" elon5ations o! 1E.2 to 27.G- res$ec@c"loroacetic aci# (9,) as a c"itin solvent. tively B37C. *i!une an# co@worers !urt"er su5@,"itin was $ulverie# an# two $arts y wei5"t 5este# t"at t"ese c"itin laments were suitalewere a##e# to D7 $arts y wei5"t o! a solvent as asorale sur5ical suture B3DC. ?owever-mi;ture containin5 40 9,- 40 c"loral 9, is very corrosive an# #e5ra#es t"e $oly@

"y#rate (= +e$artment o! ustice- +ru5


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D ... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127

Five $arts were #issolve# in 100 $arts o! a 4>4>2 u$on s"ort e;$osures. ,"loro"y#rocarons are9,/c"loral "y#rate/#ic"loroet"ane solvent increasin5ly environmentally unacce$tale sol@mi;ture an# e;tru#e# t"rou5" a 0.06 mm nole vents. ?e;aKuoro@2@$ro$anol an# "e;aKuoro@

into acetone. 9"e res were treate# wit" acetone ses8ui"y#rate are to;ic. Formic aci# canmet"anolic aJ?. 9"e o$timum res 5ave a act as a sensitier.tenacity o! G.2 5/# wit" an elon5ation o! 20B62C. nitia ,o. !ollowe# t"is u$ wit" anot"er 3.G.2. mi#eAi,l system$atent usin5 a 60>40 9,/tric"loroet"ylene n 1E7D- Rut"er!or# an# ustin summarie#s$in #o$e mi;ture. 9ensile $ro$erties were t"e $rolems encountere# in n#in5 a solventunavailale B6GC. n 1EDG- nitia ,o. s"owe# system !or c"itin B63C. ustin su55este# -@t"at a #o$e consistin5 o! t"ree $arts c"itin- 30 #imet"ylacetami#e (+c)3 Ai,l or @$arts 9,- an# 30 $arts #ic"loromet"ane coul# met"yl@2@$yrroli#one (P)3 Ai,l as sol@e s$un at a rate o! 1.7 ml/min un#er 23 vents !or c"itin. solution o! 3 w/v was

25/cm $ressure into acetone to !orm laments. otaine# wit"in 2 " wit" t"ese systems. 9"e e;trusion #ie "a# "oles o! 0.07 mm #iam@ lament was e;tru#e# !rom t"e solution usin5 a

eter- in#icatin5 a 'et velocity o! D.D m/min an# 13@5au5e nee#le into an acetone coa5ulationa tae@u$ o! 3 m/min. 9"e coa5ulation at" was at". 9"is was !ollowe# y more was"in5 an#maintaine# at 1D 8,. 9"e laments were was"e# #rawin5 in acetone. 9"e nal lament waswit" acetone at 1D 8, !or 10 min- rewoun# at 4.3 was"e# in #eionie# water. 9ensile $ro$ertiesm/min- t"en neutralie#- was"e# an# #rie#. 9"e were otaine# at 60 R.?. an# room tem$era@multilament $ro#uct "a# a total #enier o! 130 ture at an a$$lie# stress o! 0.1 cm/min. 9"ewit" a tenacity o! 2.63 5/# B6GC. similar resultant #ry tensile stren5t"s !or #i!!erent crasystem usin5 !our $arts c"itin in t"e same an# s"rim$ s$ecies ran5e# !rom 24 to 60 5/

2solvent ut a 40@"ole #ie o! 0.0D mm #iameter mm (2G63E2 Pa) B66C.eac" was also use#. 9"e 'et velocity was 10.4 Russian researc"ers s$un c"itin res out o!m/min into a 23 8, acetone at". rewin#in5 at +c/P solutions containin5 3 c"itin7 m/min !ollowe# t"e rst tae@u$ roll at 3 an# 3 Ai,l (ase# on c"itin content). 9"ese

m/min. 9"e total #enier was 173 "owever- no res were #rawn in a 30>30 et"anol/et"ylenetensile $ro$erties were re$orte# B64C. 5lycol at"- 5ivin5 an avera5e yiel# stren5t" o!

=ome o! t"e "alo5enate# solvent systems GE0 Pa wit" G elon5ation. n initialattaine# #ry tenacities o! aove G 5/# "owever- mo#ulus o! 2 MPa was also re$orte#. =cannin5t"e low wet tenacities were still un#esirale. electron microsco$y s"owe# res wit" a roun#lt"ou5" t"e re c"aracteriation was muc" rillar cross section B67C. !ollow@u$ stu#yetter !or t"ese systems- t"e $olymer c"aracteri@ s"owe# a #ecrease in t"e elasticity mo#ulus an#ation lace# molecular wei5"t as well as relative elon5ation wit" increase in t"e #e5ree#e5ree o! @acetylation !ormation. =olution o! @acetylation (12G0). From Q@ray analy@$ro$erties woul# e "ar# to otain #ue to ra$i# sis- an increase in t"e amount o! amor$"ousc"itin #e5ra#ation in t"ese solvents. lt"ou5" re5ions was oserve# wit" increase in #e5ree o!an"y#rous coa5ulation at"s were use# an# acetylation B6DC.com$are#- res were neutralie# in a8ueous 9"e ami#elit"ium systems s"owe# some o!me#ia. stu#y in com$letely an"y#rous sys@ t"e est #ry tenacities- alt"ou5" t"ey still lactems woul# e o! interest- since it may lea# to a#e8uate wet tenacities. 9"e low wet tenacitiesmore #ensely consoli#ate# res. 9"e im@ are $roaly #ue to low crystallinity an# $oor$lementation o! t"ese s$in systems re$resents a consoli#ation o! t"e re. 9"e res an# s$in$rolem #ue to t"e nature o! t"e solvents. 9, #o$es were well c"aracterie# ut t"e $olymersan# +, are corrosive an# #e5ra#e t"e $olymer use# to $re$are t"ese #o$es were not. =ome


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... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127 E

coa5ulation stu#ies were carrie# out ut a clear 6.1. P"oto5ra$"ycom$arison coul# not e ma#e. $rolem wit"

,"itosan "as im$ortant a$$lications in $"oto@t"is s$in system is t"e removal an# recovery o!5ra$"y #ue to its resistance to arasion- its

lit"ium !rom t"e re. 9"e lit"ium acts as a o$tical c"aracteristics- an# lm !ormin5 aility.Aewis aci# y solvatin5 t"e c"itin ami#e 5rou$.=ilver com$le;es are not a$$recialy retaine#t is unclear i! t"is can e com$letely reverse#y c"itosan an# t"ere!ore can easily e $ene@t"rou5" was"in5- once t"e res are !orme#.trate# !rom one layer to anot"er o! a lm y#i!!usion B70C.3.G.G. mine o;i#e/water system

ttem$ts "ave een ma#e to #evelo$ a [email protected]. ,osmetics

cess !or c"itosan res y #irect #issolutionusin5 a novel solvent system- @met"ylmor@ For cosmetic a$$lications- or5anic aci#s are$"oline o;i#e/water (J/? J)- ut no

2 usually 5oo# solvents- c"itin an# c"itosan "aveinterestin5 tensile #ata were otaine# !rom t"ese !un5ici#al an# !un5istatic $ro$erties. ,"itosan is$reliminary investi5ations B6EC. t"e only natural cationic 5um t"at ecomes

viscous on ein5 neutralie# wit" aci#. 9"esematerials are use# in creams- lotions an# $erma@

6. $$lications nent wavin5 lotions an# several #erivatives "avealso een re$orte# as nail lac8uers B7DC.

9"e interest in c"itin ori5inates !rom t"estu#y o! t"e e"aviour an# c"emical c"aracteris@ 6.G. ,"itosan as an articial sintics o! lysoyme- an enyme $resent in "umano#y Kui#s B70C. wi#e variety o! me#ical n#ivi#uals w"o "ave su!!ere# e;tensive loss@a$$lications !or c"itin an# c"itin #erivatives es o! sin- commonly in res- are actually ill"ave een re$orte# over t"e last t"ree #eca#es an# in #an5er o! succumin5 eit"er to massiveB717GC. t "as een su55este# t"at c"itosan in!ection or to severe Kui# loss. Patients mustmay e use# to in"iit ro$lasia in woun# o!ten co$e wit" $rolems o! re"ailitation aris@

"ealin5 an# to $romote tissue 5rowt" an# in5 !rom #ee$- #is5urin5 scars an# cri$$lin5#i!!erentiation in tissue culture B74C. contractures. alette et al. stu#ie# t"e e!!ect o!

9"e $oor soluility o! c"itin is t"e ma'or treatment wit" c"itosan an# saline solution onlimitin5 !actor in its utiliation. +es$ite t"is "ealin5 an# ro$lasia o! woun#s ma#e ylimitation- various a$$lications o! c"itin an# scal$el insertions in sin an# sucutaneousmo#ie# c"itins "ave een re$orte#- e.5. as raw tissue in t"e a#ominal sur!ace o! #o5s B7EC.material !or man@ma#e res B34C. Fires ma#e Sannas et al. $ro$ose# a #esi5n !or articialo! c"itin an# c"itosan are use!ul as asor@ sin- a$$licale to lon5@term c"ronic use- !ocus@ale sutures an# woun#@#ressin5 materials in5 on a nonanti5enic memrane- w"ic" $er@B3D-73-76C. ,"itin sutures resist attac in ile- !orms as a io#e5ra#ale tem$late !or synt"esisurine an# $ancreatic 'uice- w"ic" are $rolem o! neo#ermal tissue BD0C. t a$$ears t"atareas wit" ot"er asorale sutures B3DC. t "as c"itosan- "avin5 structural c"aracteristics simi@een claime# t"at woun# #ressin5s ma#e o! lar to 5lycosamino 5lycans- coul# e consi#ere#c"itin an# c"itosan res "ave a$$lications in !or #evelo$in5 suc" sustratum !or sin re$lace@wastewater treatment. ?ere- t"e removal o! ment BD1DGC."eavy metal ions y c"itosan t"rou5" c"elation"as receive# muc" attention B70-77C. 9"eir use 6.G.1. ,"itin@ an# c"itosan@ase# #ressin5sin t"e a$$aral in#ustry- wit" a muc" lar5er ,"itin an# c"itosan "ave many #istinctivesco$e- coul# e a lon5@term $ossiility B7DC. iome#ical $ro$erties. ?owever- c"itin@ase#


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woun# "ealin5 $ro#ucts are still at t"e early is accelerate# y t"e oli5omers o! #e5ra#e#c"itosan y tissue enymes an# t"is materialsta5es o! researc" BD4C.was !oun# to e e!!ective in re5eneratin5 t"e=$ares an# urray BD3C #evelo$e# a sur@

sin tissue in t"e area o! t"e woun#.5ical #ressin5 ma#e o! a c"itosan5elatin com@ :ia5ini et al. BDEC #evelo$e# an @caro;y@$le;. 9"e $roce#ure involves #issolvin5 t"eutyl c"itosan #ressin5 !or treatin5 $lasticc"itosan in water in t"e $resence o! a suitalesur5ery #onor sites. solution o! @caro;y@aci#- maintainin5 t"e $? o! t"e solution at aoututyl c"itosan was #ialye# an# !reee@#rie# to2G- !ollowe# y a##in5 t"e 5elatin #issolve# in

G$ro#uce a 10 3 203 0.3 cm so!t an# Ke;ilewater. 9"e ratio o! c"itosan an# 5elatin is G>1 to$a#- w"ic" was sterilie# an# a$$lie# to t"e1>G. 9o re#uce t"e sti!!ness o! t"e resultin5woun#. 9"is #ressin5 coul# $romote or#ere##ressin5 a certain amount o! $lasticiers suc" astissue re5eneration com$are# to control #onor5lycerol an# soritol coul# e a##e# to t"esites. :etter "istoarc"itectural or#er- etter vas@mi;ture. +ressin5 lm was cast !rom t"isculariation an# t"e asence o! inKammatorysolution on a Kat $late an# #rie# at roomcells were oserve# at t"e #ermal level- w"iletem$erature. t was claime# t"at- in contrast to

!ewer as$ects o! $roli!eration o! t"e mal$i5"ianconventional iolo5ical #ressin5s- t"is e;@ layer were re$orte# at t"e e$i#ermal level.$erimental #ressin5 #is$laye# e;cellent a#"e@9"e :ritis" 9e;tile 9ec"nolo5y Mrou$sion to sucutaneous !at.

(:99M) $atente# a $roce#ure !or main5 aara et al. BD6C $atente# a woun# #ressin5c"itin@ase# rous #ressin5s BE0EGC. n t"iscom$risin5 a nonwoven !aric com$ose# o!met"o# t"e c"itin/c"itosan res were not ma#ec"itin res ma#e y t"e wet s$innin5 tec"@y t"e tra#itional re@s$innin5 tec"ni8ue an#ni8ue. n one o! t"e e;am$les- c"itin $ow#ert"e raw materials were not !rom s"rim$ s"ell

was 5roun# to 100 mes" an# treate# in 1 ?,lut !rom micro@!un5i instea#. 9"e $roce#ure

!or 1 " at 4 8,. t was t"en "eate# to E0 8, w"ere can e summarie# as !ollows.it was treate# !or G " in a 0.G aJ? solutionto remove calcium an# $rotein in t"e c"itin (i) icro@!un5al mycelia $re$aration !rom a$ow#er- an# rinse# re$eate#ly !ollowe# y culture o! ucor muce#o 5rowin5 in a#ryin5. 9"e resultant c"itin was #issolve# in a nutrient solution.#imet"ylacetami#e solution containin5 7 wt (ii) ,ulture was"in5 an# treatment wit"lit"ium c"lori#e to !orm a 7 #o$e. !ter aJ? to remove $rotein an# $reci$itatelterin5 an# allowin5 #e!oamin5 to occur- t"e c"itin/c"itosan.#o$e was e;tru#e# t"rou5" a nole o! #iameter (iii) :leac"in5 an# !urt"er was"in5.0.06 mm an# 200 "oles into utanol at 60 8, a t a (iv) Pre$aration o! t"e #is$ersion o! resrate o! 2.2 5/min. 9"e c"itin was coa5ulate# usin5 $a$er@main5 e8ui$ment.an# collecte# at a s$ee# o! 10 m/min. 9"e (v) Filtration an# wet@lai# matt $re$arationresultant stran# was rinse# wit" water an# #rie# mi;in5 wit" ot"er res to 5ive mec"anicalto otain a lament o! 0.74 #te; wit" a stren5t" stren5t".o! 2.D 5/#en. 9"e laments were t"en cut intosta$le res. sin5 $oly(vinyl alco"ol) as a 9"is is a novel met"o#- w"ic" uses a non@rous in#er- nonwoven #ressin5s were ma#e. animal source as t"e raw material- an# t"e

*i!une et al. BD7C #evelo$e# a new woun# resultin5 micro@!un5al res are totally #i!!erent#ressin5- :esc"itin L- com$ose# o! c"itin non@ !rom normal s$un res. 9"ey "ave "i5"lywoven !aric w"ic" $rove# to e enecial in ranc"e# an# irre5ular structures. 9"e res areclinical $ractice. *im an# in BDDC "ave #e@ unmana5ealy rittle w"en t"ey are allowe# tovelo$e# a woun#@coverin5 material !rom $oly@ #ry an# a $lasticier "as to e associate# wit"electrolyte com$le;es o! c"itosan wit" sul!on@ t"e w"ole $rocess an# a wet@lai# matt is use# asate# c"itosan. t is $ro$ose# t"at woun# "ealin5 t"e asic $ro#uct.


12/34


Recently- uarelli BE4C intro#uce# anot"er !or #i5estion o! mil lactose. ,owNs mil con@tains only a limite# amount o! t"e M moiety-c"itosan #erivative- 3@met"yl$yrroli#inone"ence some in!ants !e# cowNs mil may "avec"itosan- w"ic" is elieve# to e very $romisin5

in#i5estion. any animals an# some "umansin me#ical a$$lications. 9"is $olymer is claime# (inclu#in5 t"e el#erly) "ave similar lactoseto e com$atile wit" ot"er $olymer solutions-intolerances BE6-E7C.inclu#in5 5elatin- $oly(vinyl alco"ol)- $oly@

nimal nutritional stu#ies "ave s"own t"at(vinyl $yrroli#one) an# "yaluronic aci#. 9"et"e utiliation o! w"ey may e im$rove# i! t"ea#vanta5es inclu#e "ealin5 o! woun#e# mensi@#iet contains small amounts o! c"itinous materi@cal tissues- an# o! #ecuitus ulcers- #e$ressional. 9"is im$rovement is attriute# to t"e c"an5eo! ca$sule !ormation aroun# $rost"eses- limita@in t"e intestinal microKora rou5"t aout y t"etion o! scar !ormation an# retraction #urin5c"itinous su$$lement BEDC. ,"icens !e# a com@"ealin5. =ome woun#@#ressin5 sam$les weremercial roiler #iet containin5 20 #rie# w"ey$re$are# !rom an a8ueous solution o! t"is 3@an# 2 or 0.3 c"itin "a# si5nicantly im$rove#met"yl$yrroli#one c"itosan- w"ic" was #ialye#wei5"t a5ain com$are# to controls BEE-100C.an# laminate# etween stainless steel $lates an#

9"e !ee# e!ciency ratio s"i!te# !rom 2.3 to!reee@#rie# to yiel# Keeces. 9"e material coul# 2.GD #ue to incor$oration o! c"itin in t"e !ee#e !aricate# into many #i!!erent !orms- suc" asB100C.laments- nonwoven !arics- etc. Jnce a$$lie#

to a woun#- 3@met"yl$yrroli#inone c"itosan6.3. J$t"almolo5yecomes availale in t"e !orm o! oli5omers

$ro#uce# un#er t"e action o! lysoyme.,"itosan $ossesses all t"e c"aracteristics re@

not"er c"itin #erivative- #iutyrylc"itin-8uire# !or main5 an i#eal contact lens> o$tical

was $re$are# y treatment o! rill c"itin wit"clarity- mec"anical staility- su!cient o$tical

utyric an"y#ri#e in t"e $resence o! $erc"loriccorrection- 5as $ermeaility- $articularly to@

aci# as a catalyst at 23G0 8, BE3C. =am$les o! war#s o;y5en- wettaility an# immunolo5ical$olymers wit" molecular wei5"ts "i5" enou5"

com$atiility. ,ontact lenses are ma#e !romto !orm res were otaine# an# #iutyryl

$artially #e$olymerie# an# $urie# s8ui# $enc"itin res were ma#e y #ry s$innin5 a 20 c"itosan y s$in castin5 tec"nolo5y an# t"ese22 solution into acetone. 9"e res "ave

contact lenses are clear- tou5" an# $ossess ot"ertensile $ro$erties similar to or etter t"an t"ose

re8uire# $"ysical $ro$erties suc" as mo#ulus-o! c"itin. oreover- it was claime# t"at c"itin

tensile stren5t"- tear stren5t"- elon5ation- waterres wit" 5oo# tensile $ro$erties coul# e

content an# o;y5en $ermeaility. 9"e anti@otaine# y alaline "y#rolysis o! #iutyryl

microial an# woun# "ealin5 $ro$erties o! c"itin res wit"out #estroyin5 t"e re struc@

c"itosan alon5 wit" an e;cellent lm ca$ailityture.

mae c"itosan suitale !or #evelo$ment o! s !ar as c"itin@ase# commercial woun#

ocular an#a5e lenses B101C.#ressin5s are concerne#- one $ro#uct

(:esc"itin - nitia) is commercially availale 6.6. Later en5ineerin5in a$an- w"ic" is a nonwoven !aric manu!ac@ture# !rom c"itin laments. s environmental $rotection is ecomin5 an

im$ortant 5loal $rolem- t"e relevant in#us@

6.4. Foo# an# nutrition tries $ay attention to t"e #evelo$ment o! tec"@nolo5y w"ic" #oes not cause environmental

9"e @acetyl5lucosamine (M) moiety $rolems.$resent in "uman mil $romotes t"e 5rowt" o!i#o acteria- w"ic" loc ot"er ty$es o! 6.6.1. etal ca$ture !rom wastewatermicroor5anism an# 5enerate t"e lactase re8uire# air an# a#"avan B102C use# c"itosan !or


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t"e removal o! mercury !rom solutions- an# t"e B110C. +ue to its uni8ue molecular structure-a#sor$tion inetics o! mercuric ions y c"itosan c"itosan "as an e;tremely "i5" a!nity !or manywere re$orte# y Penic"e@covas et al. B10GC. classes o! #yes- inclu#in5 #is$erse- #irect- reac@

9"e results in#icate t"at t"e e!ciency o! a#@ tive- aci#- vat- sul!ur an# na$"t"ol #yes. 9"e21sor$tion o! ?5 y c"itosan #e$en#s u$on t"e rate o! #i!!usion o! #yes in c"itosan is similar to$erio# o! treatment- t"e $article sie- initial t"at in cellulose. Jnly !or asic #yes "as

21 c"itosan a low a!nity. ,"itosan is versatile inconcentration o! ?5 an# 8uantity o! c"itosan.sorin5 metals an# sur!actants- as well as to"a et al. B104C stu#ie# t"e a#sor$tion o!

21 #erivatiation to attract asic #yes an# ot"er,# on c"itosan $ow#er over t"e concentrationmoieties (e.5.- $roteins !rom !oo# $rocessin5ran5e o! 110 $$m usin5 various $article sies$lants).y a#o$tin5 a similar $roce#ure as !or t"e

9"e sor$tion o! #yes y c"itosan is e;ot"er@removal o! mercury.mic- an increase in t"e tem$erature lea#s to an?y#ro;ymet"yl c"itin an# ot"er water@solu@increase in t"e #ye sor$tion rate- ut #iminis"esle #erivatives are use!ul Kocculents !or anionictotal sor$tion ca$acity B111C. ?owever- t"esewaste streams. ,"itosan @enylsul!onate #e@

e!!ects are small an# normal wastewater tem@rivatives were use# as sorents !or removal o!$erature variations #o not si5nicantly a!!ect t"emetal ions in an aci#ic me#ium y Leltrowsioverall #ecoloriation $er!ormance B112C. lso-et al. B103C. 9"e selective a#sor$tion ca$acityt"e wastewater $? may e an im$ortant !actor!or metal ions o! ami#o;imate# c"itosan ea#@in t"e sor$tion o! certain #yes onto c"itosan5@P co$olymer "as een stu#ie# y *an5 etecause- at low $?- c"itosanNs !ree aminoal. B106C. 9"ese investi5ations clearly in#icate5rou$s are $rotonate#- causin5 t"em to attractt"at c"itosan "as a natural selectivity !or "eavyanionic #yes. ,ontact time or- inversely- Ku;metal ions an# is use!ul !or t"e treatment o!(wastewater Kow $er unit cross@sectional area)wastewater.a!!ects sor$tion in a com$le; manner in a ;e#c*ay et al. B107C use# c"itosan !or t"e

21 21 21 21 e# #esi5n reactor system #ue to contact time-removal o! ,u - ?5 - i an# Tn wit"ine# $enetration an# oun#ary layer e!!ects. tt"e tem$erature ran5e 2360 8, at near neutral

"i5" Ku;- t"e #iversion o! li8ui# into lar5er$?. Furt"er a#sor$tion $arameters !or t"e re@c"annels aroun# $articles an# turulent Kowmoval o! t"ese metal ions were re$orte# yoccur. n 5eneral- a low Ku; ten#s to 5ive moreSan5 et al. B10DC. aruca et al. B10EC use#com$lete contaminant removal.c"itosan Kaes o! 0.44 mm !or t"e removal o!

For almost all t"e treatment strate5ies- a,r() !rom wastewater. 9"e a#sor$tion ca$aci@ma'or !actor w"ic" "as not yet een a#e8uatelyty increase# wit" a #ecrease in t"e sie o! t"ec"aracterie# is t"e e!!ect o! ty$ical wastewaterKaes- w"ic" im$lie# t"at metal ions werecontaminants on #ecoloriation e!ciencies. n$re!eraly a#sore# on t"e outer sur!ace o!ty$ical #yein5 systems it is well nown t"atc"itosan in t"e removal o! ,r() !rom t"ecertain a##itives suc" as salt an# sur!actants canwastewater. Pseu#o@rst@or#er inetics are re@eit"er accelerate or retar# #ye sor$tion $ro@$orte#.cesses. 9"e e;treme variaility o! te;tile waste@water must e taen into account in t"e #esi5no! any #ecoloriation system.6.6.2. ,olour removal !rom te;tile mill

Finally- a !actor w"ic" si5nicantly increasese!Kuentst"e sor$tion rate is t"e loa#in5 t"ermo#ynamics-

6.6.2.1. =or$tion o! #yes w"ic" in#icates w"et"er a reaction is !avoure#.o sin5le #ecoloriation met"o# is liely to s loa#in5 increases- t"e #rivin5 !orces !or

e t"e o$timum !or all wastewater streams sor$tion #ecrease- lea#in5 to an ultimate satura@


14/34

... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127 1G

tion value eyon# w"ic" !urt"er sor$tion is not ran5e 2.07.0 t"e #ye@in#in5 ca$acity o! c"itin$ossile. was s"own to e stale- w"ile c"itosan !orme#

5els elow $? 3.3 an# coul# not e evaluate#.

6.6.2.2. +ye@in#in5 $ro$erties o! c"itin an#c"itosan 6.7. Pa$er nis"in5*norr e;amine# t"e #ye@in#in5 $ro$erties

y wei5"in5 0.3 or 2.0 5 c"itin or c"itosan in ,"itosan "as een re$orte# to im$art wetcentri!u5e tues- a##in5 20 5 o! a8ueous #ye stren5t" to $a$er B117C. ?y#ro;ymet"yl c"itinsolution (3 to 4E m5 #ye/l) an# t"en s"ain5 an# ot"er water@solule #erivatives are use!ult"e close# centri!u5e tues !or G0 min at 200 en# a##itives in $a$er main5. 9"is $olymer-r$m in a "oriontal $osition. 9"e sam$les were alt"ou5" $otentially availale in lar5e 8uan@t"en centri!u5e# !or G3 min at 4300 3 5- t"e tities- never ecame a commercially si5nicantsu$ernatant #ecante# an# t"e water u$tae o! $ro#uct. 9"e entre$reneur in $a$er main5 canc"itin an# c"itosan #etermine# a!ter =osulsi utilie t"is $olymer !or etter nis" $a$erB11GC. 9"e asorance o! t"e su$ernatant was $ro$erties.

measure# at 303 nm usin5 #ecolorie# water asa lan. 9"e wei5"t o! t"e su$ernatant was use# 6.D. =oli#@state atteriesas t"e asis !or t"e calculation o! t"e totalamount o! #ye oun# or release#. $? a#'ust@ ,"itosan is insolule in water. 9"is $oses ament was carrie# out y usin5 eit"er 10 ml o! a $rolem in t"e !arication o! soli#@state $roton@commercial u!!er solution or y a##in5 0.1 con#uctin5 atteries ecause t"ere will not e?,l to a slurry o! 0.3 5 c"itin/c"itosan an# 10 any water $resent in t"e c"itosan w"ic" can actml o! #ye solution. !ter stirrin5 !or 13 min- t"e as a source o! "y#ro5en ions. n ot"er wor#s-$? was rea#'uste# an# #eionie# water a##e# to t"e $roton@con#uctin5 $olymer nee#e# !or soli#@20.3 5 total wei5"t. ,"itosan !orme# 5els at $? state attery a$$lication cannot e otaine#values elow 3.3 an# no #ye@in#in5 measure@ !rom c"itosan alone. ,"itosan is a io$olymerments coul# e otaine#. w"ic" can $rovi#e ionic con#uctivity w"en

9"e e!!ects o! #ye concentration an# c"itin/ #issolve# in acetic aci#. 9"e con#uctivity is #uec"itosan #ye solution ratios on #ye@in#in5 to t"e $resence o! $rotons !rom t"e acetic aci#ca$acity an# water u$tae o! c"itin an# c"itosan solution. 9"e trans$ort o! t"ese $rotons isare #iscusse# in #etail elsew"ere B114C. are# t"ou5"t to occur t"rou5" many microvoi#s in#i!!erences etween water u$tae o! c"itin an# t"e $olymer since t"e #ielectric constants !romc"itosan e;ist wit" c"itosan tain5 more water $ieoelectric stu#ies are small. 9"e c"oice o! at"an c"itin. 9"e #i!!erence may e #ue to more suitale electro#e material may $ro#uce a#i!!erences in crystallinity o! t"e $ro#ucts or etter attery system B11DC.#ue to #i!!erences in t"e amount o! salt@!ormin55rou$s B113C. +i!!erences in t"e amount o! 6.E. +ru5@#elivery systemscovalently oun# $rotein resi#ue mi5"t alsoa!!ect water u$tae. ,ontrolle#@release tec"nolo5y emer5e# #ur@

+ye concentrations "a# no mare# e!!ect on in5 t"e 1ED0s as a commercially soun# met"@t"e water u$tae ut correlate# si5nicantly o#olo5y. 9"e ac"ievement o! $re#ictale an#wit" t"e #ye@in#in5 ca$acity o! c"itin an# re$ro#ucile release o! an a5ent into a s$ecicc"itosan B116C. 9"e e!!ect o! $? on t"e #ye@ environment over an e;ten#e# $erio# o! timein#in5 ca$acity o! c"itin an# c"itosan was also "as muc" si5nicant merit. t creates a #esire#stu#ie#. #ecline in t"e #ye@in#in5 ca$acity environment wit" o$timal res$onse- minimumaove $? 7.0 was oserve#. Lit"in t"e $? si#e@e!!ects an# $rolon5e# e!cacy. ,ontrolle#@


15/34


release #osa5e !orms en"ance t"e sa!ety- e!ca@ tion in t"e stomac" B1GG-1G4C. lso- c"itosanmatri; !ormulations a$$ear to Koat an# 5ra#ual@cy an# reliaility o! #ru5 t"era$y. 9"ey re5ulately swell in an aci# me#ium. ll t"ese interestin5t"e #ru5 release rate an# re#uce t"e !re8uency

$ro$erties o! c"itosan mae t"is natural $olymero! #ru5 a#ministration to encoura5e $atients to an i#eal can#i#ate !or controlle# #ru5 releasecom$ly wit" #osin5 instructions. ,onventional!ormulations. any e;cellent reviews an# oos#osa5e !orms o!ten lea# to wi#e swin5s in#eal wit" t"e $ro$erties- c"emistry- ioc"emis@serum #ru5 concentrations. ost o! t"e #ru5try an# a$$lications o! c"itin- c"itosan an# t"eircontent is release# soon a!ter a#ministration-#erivatives B1-4-34-72-7G-73-1G3-1G6C.causin5 #ru5 levels in t"e o#y to rise ra$i#ly-

$ea an# t"en #ecline s"ar$ly. For #ru5s w"ose6.E.1. ?y#ro5els ase# on c"itin an# c"itosanactions correlate wit" t"eir serum #ru5 con@

?y#ro5els are "i5"ly swollen- "y#ro$"iliccentration- t"e s"ar$ Kuctuations o!ten cause$olymer networs t"at can asor lar5e amountsunacce$tale si#e@e!!ects at t"e $eas- !ollowe#o! water an# #rastically increase in volume. t isy ina#e8uate t"era$y at t"e trou5"s (Fi5. 2)well nown t"at t"e $"ysicoc"emical $ro$ertiesB11EC.o! t"e "y#ro5el #e$en# not only on t"e molecu@

new #imension is t"e incor$oration o! lar structure- t"e 5el structure- an# t"e #e5ree o!io#e5ra#aility into t"e system. numer o!

crosslinin5- ut also on t"e content an# state o!#e5ra#ale $olymers are $otentially use!ul !or

t"e water in t"e "y#ro5el. ?y#ro5els "ave eent"is $ur$ose- inclu#in5 synt"etic as well as

wi#ely use# in controlle#@release systemsnatural sustances B11E1G2C. 9"e release o!

B1G7-1GDC.#ru5s- asore# or enca$sulate# y $olymers-

Recently- "y#ro5els w"ic" swell an# contractinvolves t"eir slow an# controllale #i!!usion

in res$onse to e;ternal $? B1GE141C "ave een!rom/t"rou5" $olymeric materials. Pro#uction

e;$lore#. 9"e $?@sensitive "y#ro5els "ave $o@o! slow release (=R) #ru5s y t"e $"arma@ tential use in site@s$ecic #elivery o! #ru5s toceutical in#ustry is now a matter o! routine. s$ecic re5ions o! t"e 5astrointestinal tract (M)+ru5s covalently attac"e# to io#e5ra#ale an# "ave een $re$are# !or low molecular$olymers or #is$erse# in a $olymeric matri; o! wei5"t an# $rotein #ru5 #elivery B142C. t issuc" macromolecules may e release# y ero@ nown t"at t"e release o! #ru5s !rom "y#ro5elssion/#e5ra#ation o! t"e $olymer. 9"era$eutic #e$en#s on t"eir structure or t"eir c"emicalmolecules- com$le;e# y $olymers- may also e $ro$erties in res$onse to $? B14G-144C. 9"eserelease# !rom 5els y #i!!usion. $olymers- in certain cases- are e;$ecte# to

,"itosan is non@to;ic an# easily ioasor@ resi#e in t"e o#y !or a lon5er $erio# an#ale B74C wit" 5el@!ormin5 aility at low $?. res$on# to local environmental stimuli to mo#u@oreover- c"itosan "as antaci# an# antiulcer late #ru5 release B143C. =ometimes t"e $olymersactivities w"ic" $revent or weaen #ru5 irrita@ use# are io#e5ra#ale to otain a #esirale

#evice to control #ru5 release B146C. 9"us- to eale to #esi5n "y#ro5els !or a $articular a$$lica@tion- it is im$ortant to now t"e nature o! t"esystems in t"eir environmental con#itions. =omerecent a#vances in controlle#@release !ormula@tions usin5 5els o! c"itin an# c"itosan are$resente# "ere.

6.E.1.1. ,"itosan/$olyet"er inter$enetratin5$olymer networ (P) "y#ro5el

Sao et al. B147C re$orte# a $roce#ure !or t"eFi5. 2. ,ontrolle# #ru5 #elivery versus imme#iate release. $re$aration o! semi@P "y#ro5el ase# on


16/34


5lutaral#e"y#e@crossline# c"itosan wit" an in@ "y#ro5els as woun#@coverin5 materials an# alsoter$enetratin5 $olyet"er $olymer networ. 9"e stu#ie# t"e #ru5 release e"aviour usin5 silver$? sensitivity- swellin5 an# release inetics an# sul!a#iaine as a mo#el #ru5 B132C.

structural c"an5es o! t"e 5el in #i!!erent $?solutions were stu#ie# B1GE-140-14D-14EC. 9"e 6.E.1.G. ?y#ro5els o! $oly(et"ylene 5lycol)@co@$"ysicoc"emical $ro$erties o! t"e "y#ro5el #e@ $oly(lactone) #iacrylate macromers an# b @$en# not only on t"e molecular structure- t"e 5el c"itinstructure an# t"e #e5ree o! crosslinin5- ut also Aee an# *im B13GC re$orte# a $roce#ure !oron t"e content an# state o! t"e water in t"e $re$arin5 $oly(esteret"erester) triloc co@"y#ro5el. =ince t"e inclusion o! water si5ni@ $olymers. 9"e synt"esis o! t"e triloc co$oly@cantly a!!ects t"e $er!ormance o! "y#ro5els- a mers was carrie# out y ul $olymeriationstu#y o! t"e $"ysical state o! water in t"e usin5 low to;ic stannous octoate as catalyst or"y#ro5els is o! 5reat im$ortance to un#erstan# wit"out catalyst (Fi5. G). nvesti5ations o! t"et"e nature o! interactions etween asore# t"ermal an# mec"anical $ro$erties were carrie#water an# $olymers. Sao et al. B14EC stu#ie# t"e out. itamin - vitamin < an# rioKavin were

#ynamic water asor$tion c"aracteristics- state use# as mo#el #ru5s B134-133C. ?owever- t"ereo! water- correlation etween state o! water an# were no re$orts on swellin5 inetics an# solu@swellin5 inetics o! c"itosan$olyet"er "y#ro@ ility $arameters o! t"e 5els.5els y a$$lyin5 tec"ni8ues suc" as +=, an#some novel tec"ni8ues suc" as $ositron anni"i@ 6.E.1.4. ?y#ro5els o! $oly(et"ylene 5lycol)lation li!e@time s$ectrosco$y. macromer/ b @c"itosan

Sao et al. B140C oserve# ra$i# "y#rolysis o! n t"eir stu#ies on c"itosan !or iome#icalt"e 5el wit" #ecrease in t"e ionic stren5t"- i.e. a a$$lications- Aee et al. B136C re$orte# a $ro@"i5"er #e5ree o! swellin5 in lower ionic ce#ure !or $re$arin5 semi@P $olymer networstren5t" solution B74C. 9"e "y#rolysis o! t"e 5el "y#ro5els com$ose# o! b @c"itosan an# $oly@can e controlle# y t"e amount o! crossliner (et"ylene 5lycol) #iacrylate macromer. 9"ea$$lie#. 9"e more crossliner a##e#- t"e "i5"er "y#ro5els were $re$are# y #issolvin5 a mi;@

t"e crosslin #ensity o! semi@Ps- w"ic" re@ ture o! P


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aci#. 9"e resultin5 mi;ture was t"en cast to c"itosan (lactose/c"itosan) an# $otato starc"lms- !ollowe# y suse8uent crosslinin5 wit" wit" c"itin ($otato starc"/c"itin)- an# wit"2-2@#imet"o;y@2@$"enylaceto$"enone as non@ c"itosan ($otato starc"/c"itosan). 9"e #isinte@

to;ic $"oto initiator y irra#iation. 9"ey 5ration $ro$erties o! talets ma#e !rom t"esestu#ie# t"e crystallinity an# t"ermal an# me@ $ow#ers- in com$arison wit" t"ose o! comine#c"anical $ro$erties o! t"e 5els. $ow#ers o! lactose wit" ,, (lactose/,,)

an# $otato starc" wit" ,, ($otato starc"/

6.E.1.3. ?y#ro5els o! c"itosan/5elatin "yri# ,,) in or#er to #evelo$ new #irect@com$res@$olymer networ sion #iluents- are also re$orte# B161C. 9"e

Sao et al. B137C re$orte# a novel "y#ro5el Kui#ity o! comine# $ow#ers wit" c"itin an#ase# on crossline# c"itosan/5elatin wit" a c"itosan was 5reater t"an t"at o! t"e $ow#er5lutaral#e"y#e "yri# $olymer networ. 9"ey wit" crystalline cellulose. 9"e re$orte# "ar#nessoserve# #rastic swellin5 o! t"e 5els at aci#ic o! t"e talets !ollows t"e or#er> c"itosan$? in com$arison to asic solutions. talets

.,,

.c"itin. n #isinte5ration stu#ies-

Aevamisole- cimeti#ine an# c"loram$"enicol talets containin5 less t"an 70 c"itin or

were use# as mo#el #ru5s. $?@#e$en#ent c"itosan $asse# t"e test. oreover- t"e e'ectionrelease o! cimeti#ine- levamisole an# c"loram@ !orce o! t"e talets o! lactose/c"itin an# lac@$"enicol !rom t"e 5el was re$orte#. tose/c"itosan was si5nicantly less t"an t"at o!

lactose/crystalline cellulose talets B161C. [email protected]. ,"itosanamine o;i#e 5el ever- no re$orts are availale on controlle# #ru5

+utta et al. BG0G2C $re$are# an "omo5e@ release !ormulations usin5 t"ese talets.neous c"itosanamine o;i#e 5el an# stu#ie# itsswellin5 e"avior an# release c"aracteristics in 6.E.2.2. ,"itosan talets !or controlle# release>a u!!er solution ($? 7.4) at room tem$erature. anioniccationic inter$olymer com$le;?omo5enous erosion o! t"e matri; an# a near Recently- c"itosan "as 5aine# im$ortance as aero@or#er release o! am$icillin tri"y#rate were #isinte5ration a5ent #ue to its stron5 aility tooserve#. 9"ey re$orte# t"e t"ermal $ro$erties asor water. t "as een oserve# t"at c"itosan

o! t"e c"itosanamine o;i#e 5el in a !urt"er containe# in talets at levels elow 70 acts asstu#y BG1C. a #isinte5ration a5ent B161-162C. eau et al.

B16GC investi5ate# t"e sustaine#@release c"[email protected]. ,"itin an# c"itosan talets teristics o! et"ylcellulose talets containin5

any #irect@com$ression #iluents "ave een t"eo$"ylline as t"e mo#el #ru5. =everal e8ua@re$orte# in t"e literature- ut every #iluent "as tions were teste# to c"aracterie release mec"a@some #isa#vanta5es B13DC. icrocrystalline cel@ nisms wit" res$ect to t"e release #ata. 9"elulose (,,) "as een wi#ely use# as a talet investi5ations reveal t"at- at "i5" #ru5 loa#in5-#iluent in a$an. ,"itin an# c"itosan- ecause o! #ru5 was release# y a #i!!usion mec"anismt"eir versatility- "ave een re$orte# to e use!ul wit" a rate constant t"at increase# wit" an#iluents in $"armaceutical $re$arations increase in a8ueous soluility. t low #ru5B13E-160C. loa#in5- $olymer rela;ation also ecomes a

com$onent o! t"e release mec"anism. ?owever-6.E.2.1. +irectly com$resse# talets containin5 its contriution to #ru5 release was less $ro@c"itin or c"itosan in a##ition to lactose or nounce# as #ru5 soluility #ecrease#- ecomin5$otato starc" ne5li5ile in t"e case o! t"eo$"ylline.

=awayana5i et al. B161C re$orte# t"e Kui#ity Recently- i et al. B164C "ave re$orte#an# com$ressiility o! comine# $ow#ers o! al5inate as an anionic $olyelectrolyte to controllactose wit" c"itin (lactose/c"itin)- wit" t"e swellin5 an# erosion rates o! c"itosan talets


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in aci#ic me#ia. nvesti5ations o! t"e #ru5release mec"anism o! various talets "ave eencarrie# out ase# on Pe$$asNs mo#el B163-166C

an# nuclear ma5netic resonance ima5in5 micro@sco$y was use# to e;amine t"e swellin5/#i!!u@sion mec"anism o! various talets B164C.

6.E.G. icroca$sules/micros$"eres o! c"itosan microca$suleN is #ene# as a s$"erical

Fi5. 4. =c"ematic structure o! a c"itosan 5el micros$"ere coate#$article wit" sie varyin5 !rom 30 nm to 2 mm- wit" anionic $olysacc"ari#e an# li$i#.containin5 a core sustance. icros$"eres are-in a strict sense- s$"erical em$ty $articles.?owever- t"e terms microca$sules an# micro@ t"rou5" a $olyion com$le; !ormation reaction.s$"eres are o!ten use# synonymously. n a##i@ n t"e case o! li$i#@coate# micros$"eres- t"etion- some relate# terms are use# as well. For micros$"eres alon5 wit" #i$almitoyl $"os@

e;am$le- microea#sN an# ea#sN are use# $"ali#yl c"oline (+PP,) were #is$erse# inalternatively. =$"eres an# s$"erical $articles are c"loro!orm. !ter eva$oration o! t"e solvent-also use# !or a lar5e sie an# ri5i# mor$"olo5y. micros$"eres were otaine# coate# wit" aRecently- Sao et al. B167C "i5"li5"te# t"e $re$a@ +PP, li$i# multilayer- w"ic" e;"iite# a transi@ration an# $ro$erties o! microca$sules an# tion tem$erature o! a li8ui# crystal $"ase atmicros$"eres relate# to c"itosan. +ue to t"e 41.48,. 9"e #iameter ran5e o! t"e micros$"eresattractive $ro$erties an# wi#er a$$lications o! was 230G00 nm wit" a narrow #istriution.c"itosan@ase# microca$sules an# micros$"eres- 9"e staility o! t"e #is$ersion was im$rove# ya survey o! t"e a$$lications in controlle# #ru5 coatin5 (Fi5. 3) t"e micros$"ere wit" anionicrelease !ormulations is a$$ro$riate. oreover- $olysacc"ari#e or a li$i# multilayer.microca$sule an# micros$"ere !orms "ave an com$arative stu#y on t"e release o! 3@Fe#5e over ot"er !orms in "an#lin5 an# a#minis@ an# its #erivatives !rom a $olysacc"ari#e@coate#

tration. micros$"ere = (,) was carrie# out in$"ysiolo5ical saline at G7 8,. 9"e #ata in#icate#

6.E.G.1. ,rossline# c"itosan micros$"eres t"at t"e 3@F release rate #ecrease# in t"ecoate# wit" $olysacc"ari#es or li$i# or#er> !ree 3@F

.caro;ymet"yl ty$e 3@F

.

9"e $re$aration o! crossline# c"itosan ester ty$e 3@F. 9"e results reveale# t"at t"emicros$"eres coate# wit" $olysacc"ari#e or coatin5 layers on t"e micros$"eres were e!!ec@li$i# !or intelli5ent #ru5 #elivery systems "as tive arriers to 3@F release.een re$orte# (Fi5. 4) B167C. 9"e micros$"eres Ai$i# mutilayers wit" a "omo5eneous com@were $re$are# wit" an inverse emulsion o! 3@ $osition 5enerally s"ow a 5elli8ui# crystalKuorouracil (3@F) or its #erivative solution o! transition. L"en t"e tem$erature is raise# to"y#roc"loric aci# o! c"itosan in toluene con@ 428,- w"ic" is "i5"er t"an t"e $"ase transitiontainin5 =P D0. ,"itosan was crossline# o! 41.4 8,- t"e amount o! 3@F release# in@t"rou5" =c"i!!Ns salt !ormation y a##in5 a crease#- an# t"e amount o! #ru5 #elivere#5lutaral#e"y#e solution in toluene. t t"e same #ecrease# at G7 8,- w"ic" is lower t"an t"etime- t"e amino #erivatives o! 3@F were transition tem$erature. +ue to t"e im$rove#immoilie#- oviously resultin5 in an increase reco5nition !unction o! $olysacc"ari#e c"ainsin t"e amount o! #ru5 wit"in t"e micros$"eres. !or animal cell memranes- #elivery systems9"e micros$"eres were coate# wit" anionic !rom $olysacc"ari#e@coate# micros$"eres- =$olysacc"ari#es (e.5.- caro;ymet"ylc"itin- etc.) (,)- seem $romisin5.


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1D ... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127

oreover- t"e release rate can e controlle# viat"e com$osition o! t"e ?P an# t"e #e5ree o!#eacetylation o! c"itosan.

6.E.G.G. ,"itosan micros$"eres !or controlle#release o! #iclo!enac so#ium

Mo"el et al. B16EC re$orte# on c"itosan micro@s$"eres containin5 #iclo!enac so#ium- w"ic"were $re$are# y a coacervation $"ase se$a@ration met"o#. ,"itosan an# 5lutaral#e"y#ewere use# as coatin5 material an# crosslinin5a5ent- res$ectively. n vivo stu#ies were $er@!orme# on ew Tealan# w"ite raits. ore@over- t"e micros$"eres were !oun# to e staleat 43 8, !or G0 #ays. =tu#entNs tN test was

$er!orme# !or t"e results o! in vitro #issolution#ata !or !res" an# a5e# sam$les (G0 #ays at438,) an# no si5nicant #i!!erence was !oun#u$on stora5e.

6.E.G.4. ,"itosan$olyet"ylene o;i#eFi5. 3. Pre$aration o! = (,)- = (,A) an# = (,)$olysacc"ari#e. sc"ematic #ia5ram. nano$articles as $rotein carriers

?y#ro$"ilic nano$articulate carriers "ave6.E.G.2. ,"itosan/5elatin networ $olymer many $otential a$$lications !or t"e a#ministra@micros$"eres tion o! t"era$eutic molecules. 9"e recently

n t"eir stu#ies on t"e $"armaceutical a$$li@ #evelo$e# "y#ro$"oic"y#ro$"ilic carriers re@cations o! c"itin an# c"itosan- Sao an# co@ 8uire t"e use o! or5anic solvents !or t"eir

worers B16DC re$orte# c"itosan/5elatin net@ $re$aration an# "ave a limite# $rotein@loa#in5wor $olymer micros$"eres !or controlle# re@ ca$acity B17017GC. 9o a##ress t"ese limita@lease o! cimeti#ine. 9"e #ru5@loa#e# micro@ tions- ,alvo et al. B174C re$orte# a new a$@s$"eres were $re$are# y #issolvin5 c"itosan- $roac" !or t"e $re$aration o! nano$articles5elatin (1>1 y wei5"t) an# cimeti#ine in 3 ma#e solely o! "y#ro$"ilic $olymer. 9"e $re$a@acetic aci#. certain amount o! 9ween@D0 an# ration tec"ni8ue- ase# on an ionic 5elationli8ui# $ara!n at a water@to@oil ratio o! 1>10 was $rocess- is e;tremely mil# an# involves aa##e# to t"e c"itosan/5elatin mi;ture un#er mi;ture o! two a8ueous $"ases at room tem@a5itation at 630 r$m at G0 8,. suitale amount $erature (Fi5. 6). Jne $"ase contains t"eo! 23 a8ueous 5lutaral#e"y#e was a##e# to c"itosan (,=) an# a #iloc co$olymer o!t"e inverse emulsion an# t"e system maintaine# et"ylene o;i#e an# so#ium tri$oly$"os$"ate!or 2 ". Finally- t"e li8ui# $ara!n was va$or@ (9PP). 9"e sie (2001000 nm) an# eta $o@ie# un#er vacuum to otain micros$"eres. tential (etween 1 20 an# 1 60 m) o! t"e

9"e #ru5 release stu#ies were $er!orme# in nano$articles can e mo#ulate# conventionally"y#roc"loric aci# solution ($? 1.0) an# $otas@ y varyin5 t"e ,=/P


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... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127 1E

GE0 000 c"itosan at $? 4 (less t"an 7 losswit" re5ar# to t"e 130 5/l initial concentration).

=imilarly- t"e enca$sulation o! various mole@

cules B"aemo5loin (?)- ovine serum alumin(:=) an# #e;trans wit" various molecularwei5"tsC in calcium al5inate ea#s coate# wit"c"itosan "as een re$orte# B176-177C. 9"eirrelease "as een com$are# an# t"e inKuence o!t"e #imensions- t"e c"emical com$osition an#t"e molecular wei5"t o! t"e enca$sulate# ma@terials "ave een analyse# B176C. 9"e ionic

Fi5. 6. 9"e $re$aration o! ,= nano$articles. sc"ematic #ia@interactions etween al5inate an# c"itosan at5ram.#i!!erent $? are #e$icte# in Fi5. 7.

$rotein) an# can $rovi#e continuous release o! 6.E.G.6. ulti$orous ea#s o! c"itosan

t"e entra$$e# $rotein !or u$ to 1 wee. =everal researc"ers B17D-17EC "ave stu#ie#sim$le coacervation o! c"itosan in t"e $ro#uct@

6.E.G.3. ,"itosan/calcium al5inate ea#s ion o! c"itosan ea#s. n 5eneral- c"itosan is9"e enca$sulation $rocess o! c"itosan an# #issolve# in a8ueous acetic aci# or !ormic aci#.

calcium al5inate as a$$lie# to enca$sulation o! sin5 a com$resse# air nole- t"is solution is"aemo5loin was re$orte# y ?u5uet et al. lown into aJ?- aJ?met"anol- or et"yl@B173C. n t"e rst $rocess- a mi;ture o! "aemo@ ene#iamine solution to !orm coacervate #ro$s.5loin an# so#ium al5inate is a##e# #ro$wise to 9"e #ro$s are t"en ltere# an# was"e# wit" "ota solution o! c"itosan an# t"e interior o! t"e an# col# water successively. aryin5 t"e e;clu@ca$sules t"us !orme# in t"e $resence o! ,a,l is sion rate o! t"e c"itosan solution or t"e nole

2

"ar#ene#. n t"e secon# met"o#- t"e #ro$lets #iameter can control t"e #iameter o! t"e #ro$@were #irectly $ulle# o!! in a c"itosan,a,l lets. 9"e $orosity an# stren5t" o! t"e ea#s

2

mi;ture. :ot" $roce#ures lea# to ea#s con@ corres$on# to t"e concentration o! t"e c"itosantainin5 a "i5" concentration o! "aemo5loin aci# solution- t"e #e5ree o! @#eacetylation o!(more t"an E0 o! t"e initial concentration (130 c"itosan- an# t"e ty$e an# concentration o!5/l) is retaine# insi#e t"e ea#s) $rovi#e# t"e coacervation a5ents use#.c"itosan concentration is su!cient. 9"e c"itosan ea#s #escrie# aove "ave

9"e molecular mass o! c"itosan (243 000 or een a$$lie# in various el#s- vi. enymaticGE0 000 +a) an# t"e $? (2- 4- or 3.4) "a# only immoiliation- c"romato5ra$"ic su$$ort- a#@a sli5"t e!!ect on t"e entra$ment o! "aemo@ sorent o! metal ions- or li$o$rotein- an# cell5loin- t"e est retention ein5 otaine# wit" cultures. t was conrme# t"at t"e $orousea#s $re$are# at $? 3.4. 9"e release o! sur!aces o! t"e c"itosan ea#s !orm a 5oo# cell"aemo5loin #urin5 ea# stora5e in water was culture carrier. ?ayas"i an# a#a B1D0C im@!oun# to e #e$en#ent on t"e molecular wei5"t moilie# $rotease onto $orous c"itosan ea#so! c"itosan. 9"e est retention #urin5 stora5e in wit" a s$acer an# !oun# t"at t"e immoilie#water was otaine# wit" ea#s $re$are# wit" a $rotease "a# "i5"er $?- an# t"ermal stora5e"i5" molecular wei5"t c"itosan solution at $? staility- an# e;"iite# "i5"er activity towar#s2.0. ,onsi#erin5 t"e total loss in "aemo5loin t"e small ester sustrate @enyl@A@ar5inine#urin5 ea# !ormation an# a!ter 1 mont" o! et"yl ester. n a##ition- is"imura et al. B17DCstora5e in water- t"e est results were otaine# investi5ate# t"e $ossiilities o! usin5 c"itosany $re$arin5 t"e ea#s in an D 5/l solution o! ea#s as a carrier !or t"e cancer c"emot"era@


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"i5"er release rates at $? 12 t"an at $?7.27.4. 9"e e!!ect o! t"e amount o! #ru5loa#e#- t"e molecular wei5"t o! c"itosan an# t"e

crosslinin5 a5ent on t"e #ru5@#elivery $roles"ave een re$orte# B1D11DGC.

6.E.4. ,"itosan@ase# trans#ermal #ru5#elivery systems

9"ac"aro#i an# Rao B1D41D6C re$orte# $er@meation@controlle# trans#ermal #ru5 #eliverysystems (9+=) usin5 c"itosan. =tu#ies on $ro@$ranolol "y#roc"lori#e ($ro$@?,l) #elivery sys@tems usin5 various c"itosan memranes wit"#i!!erent crosslin #ensities as #ru5 releasecontrollin5 memranes an# c"itosan 5el as t"e

#ru5 reservoir "ave een $er!orme#. 9"e$"ysicoc"emical $ro$erties o! t"e memranes"ave een c"aracterie# an# t"e $ermeailityc"aracteristics o! t"ese memranes to ot"li$o$"ilic an# "y#ro$"ilic #ru5s "ave eenre$orte# B1D4-1D3C. n vitro evaluations o! t"e9+= #evices w"ile su$$orte# on rait $innasin were carrie# out in mo#ie# Fran #i!!u@sion cells B1D6C. 9"e in vitro #ru5 release$roles s"owe# t"at all #evices release# $ro$@?,l in a reliale- re$ro#ucile manner. 9"e#ru5 release was si5nicantly re#uce# w"en

crossline# c"itosan memranes were use# tore5ulate #ru5 release in t"e #evices. oreover-t"e #ru5 release rate was !oun# to #e$en# on t"ecrosslin #ensity wit"in t"e memranes. t wasoserve# t"at t"e #evice constructe# wit" a

Fi5. 7. =c"ematic re$resentation o! t"e ionic interactions etweenc"itosan memrane wit" a "i5" crosslin #en@al5inate an# c"itosan> (a) $? 3.4 () $? 2.0.sity release# t"e minimum amount o! #ru5. 9"isis #ue to t"e #ecrease# $ermeaility coe!cient

$eutic a#riamycin. Recently- ="arma et al. o! crossline# memranes resultin5 !rom t"eB1D11DGC $re$are# c"itosan microea#s !or crosslin $oints.oral sustaine# #elivery o! ne!e#i$ine- am$icillinan# various steroi#s y a##in5 t"ese #ru5s to 6.10. :iotec"nolo5yc"itosan an# t"en enterin5 a sim$le coacerva@tion $rocess. 9"ese coacervate ea#s can e 6.10.1. Pre$aration o! iotec"nolo5ical"ar#ene# y crosslinin5 wit" 5lutaral#e"y#e or materialse$o;yc"loro$ro$ane to $ro#uce microca$sules ,"itin "as two "y#ro;yl 5rou$s- w"ilecontainin5 rotun#ine B167C. 9"e release $roles c"itosan "as one amino 5rou$ an# two "y#ro;ylo! t"e #ru5s !rom all t"ese c"itosan #elivery 5rou$s in t"e re$eatin5 "e;osami#e resi#ue.systems were monitore# an# s"owe#- in 5eneral- ,"emical mo#ication o! t"ese 5rou$s an# t"e


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re5eneration reaction 5ives rise to various novel late#- an# t"e sel!@#e!ence !unction a5ainstio!unctional macromolecular $ro#ucts "avin5 microial in!ection was en"ance# at t"e cellulart"e ori5inal or5aniation or new ty$es o! or5ani@ level. Jn t"e asis o! t"ese results- several

ation. c"itin an# c"itosan #ressin5 materials (#iscusse#in t"e !ore5oin5 sections) "ave een #evelo$e#commercially !or t"e "ealin5 treatment o! 6.10.2. ,ell@stimulatin5 materials"uman an# animal woun#s.

6.10.2.1. n $lantsainly two in#s o! e;tracellular c"itinase 6.10.G. ntiacterial a5ents

were !oun# in t"e normal cell sus$ension cul@ 9"e 5rowt" o!


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im$rovin5 muscle tone- metaolism an# "ealt". *oc"i- n#ia- !or $rovi#in5 t"e sam$le o! any su$$lements can "el$ in t"e !at re#uction c"itosan. 9"e aut"or is 5rate!ul to t"e ,ouncil$rocess- inclu#in5 $yruvate an# c"itosan. Pyru@ o! =cientic an# n#ustrial Researc" (,=R)-

vate- !oun# in re# a$$les- some ty$es o! c"eese- inistry o! ?uman Resource +evelo$mentan# re# wine- stimulates !at loss an# oosts Mrou$s- Movt. o! n#ia- ew +el"i- !or nanciale;ercise $er!ormance. ,"itosan attac"es itsel! to assistance to carry out t"is researc". 9"e aut"or!at in t"e stomac" e!ore it is #i5este#- t"us is in#ete# to t"e re!erees !or a t"orou5"tra$$in5 t"e !at an# $reventin5 its asor$tion y revision o! t"e manuscri$t.t"e #i5estive tract. Fat in turn in#s to t"ec"itosan re- !ormin5 a mass w"ic" t"e o#ycannot asor- an# w"ic" is eliminate# y t"e Re!erenceso#y. ,"itosan re #i!!ers !rom ot"er res int"at it $ossesses a $ositive ionic c"ar5e- w"ic" B1C R... uarelli ( Procee#in5s o! t"e Gr# sian 9e;tile ,on!er@

oral #elivery o! $olar #ru5s to inclu#e $e$ti#esence- 1EE3- $. GE.

an# $roteins an# !or vaccine #elivery. 9"ese B10C .T. *naul- *... ,reer- ,oa5ulation rate stu#ies o!s$innale c"itosan solutions- . $$l. Polym. =ci. 66 (1EE7)$ro$erties- to5et"er wit" t"e very sa!e to;icity117.$role- mae c"itosan an e;citin5 an# $romis@

B11C . =aamoto- ?. 9sen5- *. Furu"ata- Re5ioselective c"lori@in5 e;ci$ient !or t"e $"armaceutical in#ustry !or nation o! c"itin wit" @c"lorosuccinimi#etri$"enyl$"os@

$"ine un#er "omo5eneous con#itions in lit"ium c"lori#e$resent an# !uture a$$lications. 9"ans to t"e-@#imet"ylacetami#e- ,aro"y#r. Res. 263 (1EE4) 271.

ioactivities o! c"itosan itsel!- its !ormulations B12C ?. 9sen5- *. Furu"ata- . =aamoto- :romination o!wit" #ru5s may "ave #ual t"era$eutic e!!ects. re5enerate# c"itin wit" @romosuccinimi#e an# tri@$"enyl$"os$"ine un#er "omo5eneous con#itions in lit"ium

romi#e-@#imet"ylacetami#e- ,aro"y#r. Res. 270

(1EE3) 14E.cnowle#5ementsB1GC ?. 9sen5- R. Aee- *. Furu"ata- . =aamoto- :romination

o! c"itin wit" triromoimi#aole an# tri$"enyl$"os$"ine in9"e aut"or t"ans +r *.M. Ramac"an#ran lit"ium romi#e#imet"ylacetami#e- =en@ Maais"i 31

air- ,entral nstitute o! Fis"eries 9ec"nolo5y- (1EE3) 340.


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... Ravi *umar / Reactive & Functional Polymers 46 (2000) 127 2G

B14C *. *urita- ?. Sos"ino- *. Soota- . n#o- =. noue- =. BG4C *. *ai!u- . is"i- 9. *omai- Pre$aration o! "e;anoyl-s"ii- =. is"imura- Pre$aration o! tosyl c"itins as $recursors #ecanoyl an# #o#ecanoyl c"itin- . Polym. =ci.- Part >!or !acile c"emical mo#ication o! c"itin- acromolecules Polym. ,"em. 1E (1ED1) 2G61.23 (1EE2) G7D6. BG3C . :a;ter- . +illon- *.+.. 9aylor- M..F. Roerts-

B13C *. *urita- =. noue- =. is"imura- Pre$aration o! solule m$rove# met"o# !or R #etermination o! t"e #e5ree o!

c"itin #erivatives as reactive $recursors !or controlle# mo#i@ @acetylation o! c"itosan- nt. . :iol. acromol. 14 (1EE2)cations> tosyl@ an# io#o c"itins- . Polym. =ci.- Part > 166.Polym. ,"em. 2E (1EE1) EG7. BG6C M.. a5"ami- M..F. Roerts- =tu#ies on t"e a#sor$tion o!

B16C +.. Auyen- . Rossac"- i;e# esters o! c"itin- . $$l. anionic #yes on c"itosan- aromol. ,"em. 1DE (1EDD)22GE.Polym. =ci. 33 (1EE3) 67E.

BG7C . +omar#- ,ircular #ic"roism stu#y on @B17C .9. Uuras"i- ?.=. :lair- =.. llen- =tu#ies on mo#ie#acetyl5lucosamine oli5omers- nt. . :iol. acromol. Dc"itosan memranes- - . $$l. Polym. =ci. 46 (1EE2) 233.(1ED6) 24G.B1DC .9. Uuras"i- ?.=. :lair- =.. llen- =tu#ies on mo#ie#

BGDC . +omar#- $? an# c.#. measurements on a !ullyc"itosan memranes. . +ialysis o! low molecular wei5"t

#eacetylate# c"itosan> a$$lication to ,u $olymer interac@metaolites- . $$l. Polym. =ci. 46 (1EE2) 26G.tions- nt. . :iol. acromol. E (1ED7) ED.B1EC . *uota- Permeation $ro$erties o! c"itosan transition metal

BGEC S.,. Lei- =.. ?u#son- :in#in5 o! so#ium #o#ecyl sul!atecom$le; memranes- . $$l. Polym. =ci. 64 (1EE7) D1E.to a $olyelectrolyte ase# c"itosan- acromolecules 26B20C =. ?irano- !acile met"o# !or t"e $re$aration o! novel(1EEG) 4131.memranes !rom @acyl an# @aryli#ene c"itosan 5els-

B40C ?. =as"iwa- ?. =aimoto- S. ="i5emasa- R. J5awa- =.5ric. :iol. ,"em. 14 (1E7D) 1EGD.

9oura- +istriution o! t"e acetami#o 5rou$ in $artiallyB21C M.L. rancy- :. Ai$$@=ymonowic- 9"e inKuence o! #eacetylate# c"itins- ,aro"y#r. Polym. 16 (1EE1) 2E1.$rocessin5 terms o! c"itosan memranes ma#e o! #i!!erentlyB41C ?. =as"iwa- ?. =aimoto- S. ="i5emasa- =. 9oura- @cetyl#eacetylate# c"itosan on t"e crystalline structure o! mem@

5rou$ #istriution in $artially #eacetylate# c"itins $re$are#ranes- . $$l. Polym. =ci. 31 (1EE4) 21E1.un#er "omo5eneous con#itions- ,aro"y#r. Res. 242 (1EEG)

B22C *. *urita- *. 9omita- =. s"ii- =. is"imura- *. ="imo#a-167.

b @,"itin as a convenient startin5 material !or acetolysis !or B42C A. Raymon#- F.M. orin- R.?. arc"essault- +e5ree o!e!cient $re$aration o! @acetylc"itooli5osacc"ari#es- .

#eacetylation o! c"itosan usin5 con#uctometric titration an#Polym. =ci.- Part > Polym. ,"em. G1 (1EEG) 2GEG.

soli#@state R- ,aro"y#r. Res. 24G (1EEG) GG1.B2GC *.R. ?olme- A.+. ?all- ,"itosan #erivatives earin5 , @

10 B4GC F. iola- . :asora-


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B34C 9.+. Rat"e- =.. ?o#son- Review o! c"itin an# c"itosan as B76C R... uarelli- ,. uarelli- . 9ero'evic"- ,"itinc"emistry u$5ra#in5 a renewale resource- ,aro"y#r. R.*. 9rive#y ( 9.+. ,"urc" ( !unctional e;tension o! sin- =cience 213 (1ED2) 174.

Pre$aration o! c"itin res- Polym. . (9oyo) 11 (1E7E) BD1C S. Ae- =.,. nan#- .R. ?orrocs- +evelo$ment o! anti@7D1. acterial $olysacc"ari#e res an# t"eir $er!ormance- in>

3344E5.

BD2C R. Jlsen- +. =c"wartmiller- L. Le$$ner- R. Linan#y- in> M.B62C nitia ,o.- At#.- a$anese Patent 371GE101 (1ED2) ,"em. ='a@:rac- 9. nt"onsen- P.. =an#!or# ( =ources- ,"emistry- :ioc"emistry- P"ysical Pro$@B6GC nitia ,o.- At#.- a$anese Patent 3D21431G (1EDG) ,"em.erties an# $$lications- 1D01GDr.Sor- 1EDE.

B64C nitia ,o.- At#.- a$anese Patent 3D214312 (1EDG) ,"em.BDGC +.. =an#!or#- . =tinnes ( 1D01GEs.o! ?i5" Purity ,"itosan P"ysical- ,"emical an# :ioactive

B63C F.. Rut"er!or# - P.R. ustin- arine c"itin $ro$erties an#Pro$erties- ,= =ym$osium =eries- ol. 467- 1EE1- $. 4G0.

solvents- in> R... uarelli- .P. BD6C *. ara- S. Sama5uc"i- ?. 9ane- = Patent 4631723 (1ED7).

Tiais ( BE1C :. =a5ar- P. ?amlyn- +. Lales- * Patent 21DDD1G3 (1ED7).D3662. BE2C :. =a5ar- P. ?amlyn- +. Lales- * Patent 214DE3E (1ED3).

B6EC P.*. +utaa- ... Ravi *umar- Laste utiliation> c"itosan BEGC :. =a5ar- P. ?amlyn- +. Lales- * Patent 2163D63 (1ED6).res y #irect #issolution- in> n#ian ,"emist ,onvention- BE4C R... uarelli- = Patent 3G7D472 (1EE3).

ew +el"i- +ec. 1720- 1EE7. BE3C :. =oslan#- M.,. Mui#e to BEEC *.. =$reen- .P. Tiais- P.R. ustin- in> .P. Tiais (


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B102C *.M.R. air- P. a#"avan- ,"itosan !or removal o! mer@ B124C ... Ravi *umar- M. a#"ava Re##y- P.*. +utta- =tu#y

cury !rom water- Fis"ery 9ec". 21 (1ED4) 10E. o! $aracetamol release !rom castor@oil ase# co$olyester

B10GC ,. Penic"e@covas- A.L. lware- L. r5uelles@onal- 9"e matri;- ranian Polym. . 3 (1EE6) 60.a#sor$tion o! mercuric ions y c"itosan- . $$l. Polym. B123C ... Ravi *umar- . *umar- Polymeric controlle# #ru5=ci. 46 (1ED7) 1147. #elivery systems> $ers$ective issues an# o$$ortunities-

B104C . "a- . Aeela- ..=. Pra"aar Rao- Removal o! ca#@ +ru5 +ev. n#. P"arm. (in $ress).mium usin5 c"itosan- . .B1G0C L. R"ine- +. ?sie"- R. Aan5er- Polymers o! sustaine#

o"nson (

B1G4C =. iyaai- *. s"ii- 9. a#ai- 9"e use o! c"itin an#B113C +. *norr- Functional $ro$erties o! c"itin an# c"itosan- .c"itosan as #ru5 carriers- ,"em. P"arm. :ull. 2E (1ED1)Foo# =ci. 47 (1ED2) 3EG.

G067.B116C +. *norr- +ye in#in5 $ro$erties o! c"itin an# c"itosan- .B1G3C 9. ,"an#y- ,.P. ="arma- ,"itosan as a iomaterial-Foo# =ci. 4D (1EDG) G7.

:iomater. rti!. ,ells rti!. Jr5ans 1D (1EE0) 1.B117C M. llan- M.+. ,ros$y- .?. Aee- .A. iller- L.. Rei!-B1G6C 9. ,"an#y- ,.P. ="arma- :io#e5ra#ale c"itosan matri; !orin> Procee#in5s o! a =ym$osium on an@ma#e Polymers in

t"e controlle# release o! steroi#s- :iomater. rti!. ,ellsPa$er ain5- ?elsini- Finlan#- 1E72.mmoiliation :iotec"nol. 1E (1EE1) 743.B11DC A. ro!- R.?.S. =uan- =. Ra#"aris"na- in> P.. Prasa#

B1G7C . *ost- R. Aan5er- in> .. Pe$$as ( Polym. ,"em. G2 (1EE4) 121G."y#ro;y$ro$ylcellulose y r"iomucor> e!!ects on release

B140C *.+. Sao- 9. Pen5- .Q. Qu- ,. Suan- .F.. Moosen- U.!rom t"eo$"ylline"y#ro;y$ro$ylcellulose talets- nt. . T"an5- A. Ren- $? #e$en#ent "y#rolysis an# #ru5 releaseP"arm. 1D0 (1EEE) 103.o! c"itosan/$olyet"er inter$enetratin5 $olymer networB121C ,. lvare@Aoreno- .A. Mome@moa- R. artin@Pac"@"y#ro5el- Polym. nt. G4 (1EE4) 21G.eco- ,. =outo- . ,onc"eiro- icroviscosity o! "y#ro;y@

B141C 9. =aiyama- ,.?. ,"u- 9. Fu'i- 9. Sano- Pre$aration o!$ro$ylcellulose 5els as a asis !or $re#iction o! #ru5$olyelectrolyte com$le; 5el !rom c"itosan an# @car@#i!!usion rates- nt. . P"arm. 1D0 (1EEE) E1.ra5eenan an# its $? sensitivity swellin5- . $$l. Polym.B122C +. 9eomim- . ysa- .. +om- Ricinoleic aci# ase#=ci. 30 (1EEG) 2021.io$olymers- . :iome#. ater. Res. 43 (1EEE) 23D.

B12GC R.A. Reis- .. ,un"a- ,"aracteriation o! two io#e5ra@ B142C . :ronste#- . *o$ece- ?y#ro5els !or site s$ecic oral

#ale $olymers o! $otential a$$lications wit"in t"e ioma@ #ru5 #elivery synt"esis an# c"aracteriation- :iomaterials

terial el#- . ater. =ci.> ater. e#. 6 (1EE3) 7D6. 12 (1EE1) 3D4.


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B14GC =.:. itra- in> =.L. ="alay- .=. ?o!!man- :.+. Ratner- B160C =. iyaai- ,"itin an# c"itosan as ve"icle !or #ru59.. ?orett ( e!!ect o!

c"itosan> $olyet"er inter$enetratin5 $olymer networ- . $olymer #ru5 wet or #ry len#in5 an# anioniccationic

$$l. Polym. =ci. 4D (1EEG) G4G. inter $olymer- . $$l. Polym. =ci. 66 (1EE7) 24E3.

B14DC 9. Pen5- *.+. Sao- .F.. Moosen- =tructural c"an5es o! B163C .. Pe$$as- .. =a"lin- sim$le e8uation !or t"e #escri$@

$? sensitive c"itosan/$olyet"er "y#ro5els in #i!!erent $? tion o! solute release. . ,ou$lin5 o! #i!!usion an#

solution- . Polym. =ci. - Part > Polym. ,"em. G2 (1EE4) rela;ation- nt. . P"arm. 37 (1EDE) 16E.

3E1. B166C P.A. Rit5er- .. Pe$$as- sim$le e8uation !or #escri$tion

B14EC *.+. Sao- . Ain- R.T. T"ao- L.?. Lan5- A. Lei- +ynamic o! solute release. . Fician an# non@Fician release !romwater asor$tion c"aracteristics o! c"itosan ase# "y#ro@ non@swellale #evices in t"e !orm o! slas- s$"eres- cylin@

5els- n5ew. aromol. ,"em. 233 (1EED) 71. #ers or #iscs- . ,ontrol. Release 3 (1ED7) 2G.

B130C =.=. *im- S.. Aee- ,.=. ,"o- =ynt"esis an# $ro$erties o! B167C *.+. Sao- 9. Pen5- .. Su- .Q. Qu- .F.. Moosen-

semi@inter$enetratin5 $olymer networs com$ose# o! b @ icroca$sules/micros$"eres relate# to c"itosan- ..=.@

c"itin an# $oly(et"ylene 5lycol) macromer- Polymer G6 Rev. acromol. ,"em. P"ys. ,G3 (1EE3) 133.

(1EE3) 44E7. B16DC S.. Su'i- .Q. Qu- Q. ,"en- *.+. Sao- +ru5 release

B131C =.=. *im- S.. Aee- ,.=. ,"o- =emi@inter$enetratin5 $oly@ e"avior o! c"itosan/5elatin networ $olymer micro@

mer networs com$ose# o! b @c"itin an# $oly(et"ylene s$"eres- ,"in. =ci. :ull. 41 (1EE6) 1266.

5lycol) macromer- . Polym. =ci.- Part > Polym. ,"em. GG B16EC .,. Mo"el- .. ="et"- .. Patel- M.*. ani- ?. Patel-

(1EE3) 22D3. +esi5n o! c"itosan micros$"eres containin5 #iclo!enac

B132C S.. Aee- =.=. *im- ,.=. ,"o- Loun# coverin5 materials o! so#ium- n#ian . P"arm. =ci. 36 (1EE4) 210.

semi@inter$enetratin5 $olymer networ "y#ro5els com$ose# B170C R. Mre!- S. inamitae- .9. Peracc"ia- . 9ruetsoy- .

o! $oly(et"ylene 5lycol) #iacrylate macromers an# b @c"it in 9orc"ilin- R. Aan5er- :io#e5ra#ale lon5@circulatin5 $oly@

an# t"eir release o! silver sul!a#iaine- in> G6t" P, meric micros$"eres- =cience 1D (1EE4) 1600.

nternational =ym$osium on acromolecules- =eoul- B171C . mi'i- *. Par- in> =.L. ="alay- S. a#a- R. Aan5er- .*orea- u5. 4E- 1EE6. Lilliams ( e!!ect o! structure enca$sulate# materials on

ater. =ci.> ater. e#. D (1EE7) 3G7. t"eir release- Process :ioc"em. G1 (1EE6) 743.

B137C *.+. Sao- S.. Sin- .Q. Qu- F. Lan5- nvesti5ation o! $? B177C .A. ?u5uet- R.. eu!el#- com$arison

$olymer networ- Polym. nt. GD (1EE3) 77. o! c"itosan an# +


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materials- Polym. nt. 4D (1EEE) 7G2


B17EC M. #a- ,. onica- . nnalia- ,. :ice- . Auisa- nKuence B1DDC =. ?irano- . ?ayas"i- =. Juno- in> L.F. =tevens- .=.

o! 5lutaral#e"y#e on #ru5 release an# mucoa#"esive $ro$@ Rao- =. ,"an#raranc"an5 ( ,.M. Meelein- ,.


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28501488 a Review of Chitin and Chitosan Applications