1966_conrad Et Al._surface Modifying Effects of Lanolin Derivatives (Jscc)

8/13/2019 1966_conrad Et Al._surface Modifying Effects of Lanolin Derivatives (Jscc)

1/13

J. Soc. CosmeticChemists, 17, 157-169 (1966)

SurfaceModifyingEffectsLanolin Derivatives

of

LESTER I. CONRAD, B.S., HENRY F. MASO, B.S.and SHIRLEY A. DERAGON, B.S.*PresentedMarch 1O, 1965, A ustralian SocietyofCosmeticChemists,Sydney

Synopsis--The influence of lanolin derivatives on the physical aspects of dispersions s dis-cussed. Particular reference is made to pigment wetting, rheological patterns in emulsionsystems,solubilization, emulsificationand spreadingcoefficients. Practical applications ofthese phenomena are illustrated by typical cosmetic formulations.

INTRODUCTIONThis presentation is concernedprimarily with the influence oflanolin derivatives on the physical aspectsof dispersions. Lanolin isknown to contain many chemicalgroupsand configurationswhich arepotentially surface-active. However, due to the manner in which these

groups are chemically bound, they cannot achieve that potential. As aresult, lanolin itself is relatively poor when considered rom the view-point of surfaceactivity. Fortunately, by meansof chemicaland phys-ical proceduresanolin can be converted nto very useful unctional deriv-atives of predictable surface activity. Whereas formerly lanolin wasemployed mostly for the marketing advantages of having ContainsLanolin on the label, derivatives of lanolin are now widely used or theirability to modify the surfacesof dispersed ystemsas well as for emollienteffects on the skin.* American Cholesterol Products, Inc., Edison, N. J.

157


2/13

158 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS

CHEMISTRY OF LANOLINFor a clear understanding of the subject it is necessary o reviewbriefly the chemistry of lanolin and its derivatives. Unfortunately, thecompositionof lanolin fluctuateswidely, both qualitatively and quanti-tatively, from lot to lot. Variables such as heredity, environment, andfood supply affect the complexchemistry of this natural secretionof thesheep's sebaceous glands. Additional variations are introduced byaging, wool storage conditions,and scouringmethods.

Esters

Lanolin consists f approximately95% esters,4% free alcohols, ndfree fatty acids and hydrocarbons. The ability of lanolin to formW/O emulsions s due to the small free alcohol and fatty acid content.

Figure 1. Composition of lanolinesters

The ester fraction contributes very little to surface activity but is im-portant as a chemical ntermediate and raw material of unique composi-tion for the synthesisof derivatives. The nature of the esters s pre-sentedgraphically n Figure 1, which showsa 50/50 division of the alco-hols and acidswhich composehe esters. There are presentboth mono-and dihydric alcoholsas well as normal, branched, and hydroxy acids.This assortmentof reactive groups n compounds aving a wide range ofmolecularweights (Co to C3,) results n an extremely large variety ofesters.

AlcoholsThe compositionof lanolin alcoholss detailed n Table I. Cholesterol,of course, s the best known of these, but there are many other usefulalcoholspresent. It is interesting hat squalene, he highly unsaturatedhydrocarboncharacteristicof human sebum, s not found n the unsapon-ifiable fraction of lanolin. Glycerol s also completelyabsent.


3/13

SURFACE EFFECT OF LANOLIN DERIVATIVES

Table IComposition of Lanolin Alcohols

159

A liphatic AIcoholsNormal (Cs to C.,)Branched chain (C17 to C.,)Diols (C1 to C.,4) five members isolated in 1951

SterolsCholesterol C.,7H460Dihydrocholesterol (cholestanol) C.,,H4sOCerebrosterol C27H4702

Triterpene AlcoholsLanosterol C.0H500Dihydrolanosterol Ca0H520Agnosterol C30H4sODihydroagnosterol Ca0H00

Hydrocarbons-Unclassified--at present

18%4-5%25%5%

snall amount

o%lo%1%4%


4/13

160 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTSFlow Diagram

The Lanolin Derivatives Flow Diagram (Fig. 2) graphicallyportraysthe chemical nd processingelationshipsetweenhe various eriva-

LANOLIN

IsaponilficationI TOALFA}TLCOHOSlACIDS

fraetionation

adsorption

extraction

SURFACE

ACTIVE

ALCOHOL

acylation (acetic)ethoxylation 75 molesEO)solvent fractionation

Acetylated fanolinEthoxylated lanolinLanolin oil

esterificationisopropanol) Isopropylanolate

--further fractionation -L blendingLiquidmulti-sterolxtractolid multi-sterol extractAbsorption base--crystallization CholesterolSPethoxylation24olesO)Ethoxylatedholesterol

(16molesO)-- ethoxylationI-(25 moles EO)---- Ethoxylated lanolin alcohols

Ethoxylated lanolin alcohols

(acetie)--fractionation--Aeetylatedanolinlcohols--esterificationI-(ricinoleic) Lanolinalcoholsicinoleater- acetylation

thoxylation-]I_ acetylationPartially acetylated ethoxylated esterCompletely eetylated thoxylated ster

Figure . Flowdiagramhowingheusual rocessesmployedor themanufacturefdifferent lanolin derivativestives. It will be notedthat there are four generalprocessespplicableto anolin irectly. These reacylation,thoxylation,olventractiona-tion,andsaponification.n additionalrocess,earrangement,s alsobeing sedo produceew roductsytheacidolysisf anolin3).

The anolinatty acidsend hemselveso esterification,eutraliza-tion o form oaps,ndethoxylation. he anolin lcoholsresubjectedto manyprocessesncludingractionation,dsorption,nd extraction


5/13

SURFACE EFFECT OF LANOLIN DERIVATIVES 161

to obtain the surface-active raction, which can then be processedurtherto form multi-sterol extracts and absorptionbases. Cholesterol s pro-duced rom this fraction by crystallization. By ethoxylating cholesterol,a derivative with hydro-alcoholic solubility properties is obtained.Other lanolin alcohol products are prepared directly from the surface-active alcohol fraction by ethoxylation. Another processemployed isesterification. Stepssuchas ethoxylation and acetylation are then car-ried out on esterified lanolin alcohols. g2uaternizationhas resulted ininterestingexperimentalproductswith unusualsubstantivitywhen ap-plied to skin and hair.

KSULTS AND DISCUSSIONPigment Wetting

The effect of lanolin derivatives on the wetting and dispersingoffinely ground solids n various iquid vehicleshas been exploredexten-sively. Lanolin products differ considerably n their pigment wettingaction, a number of them being outstanding n this regard. It was as-sumed hat wetting and dispersingmplied deflocculation r reductionofagglomerated articles o the primary particlestate. Consideration asgiven o the role of the derivative n terms of its orientation o and ad-sorptionon the particle surface. The hydrophilic-lipophilic ontrastwithin the molecule and association endenciesof portions of the deriva-tive molecule were all regarded as important factors contributing tocompatibilitybetween he particle surface, he lanolin derivative, andthe vehicle. Lanolin products probably also function by lubricatingthe particle surfaceand by displacing herefrommaterialswhich mightinterfere with their adsorption onto the surface.Wetting is regardedas a significant nterfacial phenomenon nvolvedin dispersing olids. After preliminarystudies,a simple echniquewasselected to evaluate the comparative wetting performance of lanolinderivatives. The method employedwas adapted from the paint indus-try where t hasbeenusedextensively4). Recentstudies avealsoap-plied hismethod o materials f interest n cosmetics5).The test consistsof adding increments of vehicle from a burette topowders ontaininganolinderivatives s additives. The incorporationof each ncrement s accomplishedmanually, and the mixture is workedto a uniform consistency. When a cohesivemass is formed, an endpoint s read, referred o as the Wet Point. Further vehicleadditionssoften he mixture until a point is reachedat which it flows; this volumeis called the Flow Point.


6/13


The Wet Point and the Flow Point are indicative of the wettingability of a particular additive for a specificsystem. Since the wettingactivity is inversely proportional to the volume of liquid vehicle added,a lower value signifiesgreater activity.The ratios of derivatives to powders employed were in practicalranges for eventual use in finished formulations. The Wet and FlowPoints were found to be reproducibleand demonstrateda quantitativerelationship in each specificsystem.Table III shows he comparative efficiency of three lanolin deriva-tives in the wetting of several powders n mineral oil (70 Saybolt).

Table IIIWet and Flow Points in Mineral Oil (70 Saybolt)

TiO2 Tale Oxy Red D&C Red #9Wet Flow Wet Flow Wet Flow Wet Flow

Deriv./powder ratio Pt. Pt. Pt. Pt. Pt. Pt. Pt. Pt.Amerchol L-101

10% of powder 30 238 31 174 30 113 28 10520% of powder 12 47 18 165 7 58 16 83A cetulan

lO% of powder 34 242 28 198 30 129 32 9820% of powder 14 34 15 184 7.5 109 18 86A merlate P

10% of powder 23 61 27 127 11 43 3,5 9320% of powder 16 51 18 106 3 35 20 81Control Min. Oil)

10% of powder 44 258 33 259 38 124 33 10820% of powder 36 249 23 247 26 112 23 96

The results are given in terms of cc. of mineral oil per 100 g. of powder.Controls at 10 and 20% show he effect of usingmineral oil insteadof thederivative n the powdermixture. The data in Table III representonlyonephaseof the work on pigmentwetting and are ncludedhere o showthe value of the test method as a screening echnique. Differences nwetting performance re shown. These are validated by actual experi-ence with finished formulations employing the above materials.Microscopicexaminationwas also employedand found to be veryuseful or supplementingWet and Flow Point data. Systemsexaminedmicroscopically t the Flow Point exhibitedcompletedeflocculation ndgood dispersionwhen the Flow Point was low. At high Flow Points


7/13


incompletedefiocculation nd poor dispersionwere apparent under fairlylow magnification (100X). Sedimentation studies were utilized forestimating the influence of lanolin derivatives on the deflocculationofagitated iquid dispersions. It is apparent at this stageof the investiga-tion that Amerlate P is an outstanding dispersingagent for pigments inboth emulsified and anhydrous systems. This may be attributed to itschemicalcomposition, onsisting f the isopropylestersof branchedandhydroxy lanolin fatty acids in a broad range of carbon lengths. Theunique lubricity resulting from this compositionmay play a significantrole in the dispersingactivity of the product. These factors also con-tribute to a reduction of shear requirements in formulations containingAmerlate P. The data in Table III confirm empirical findings whichhad led to the extensiveuse of this material in pigmented products.The following formulas (a and b) illustrate the practical applicationof these principles in makeup items:

(a) Anhydrous MakeupAcetulan 6%Amcrlate P 3Mineral oil (70 Saybolt) 36Microwax, m.p. 170 F 15Talc, TiO2, Pigments 40Perfume q.s.

(b ) Liquid Crearn Makeup (Highly Pigmented)Amerchol L-101 4.0Amerlate P 3.0Stearic acid, XXX 2.0Glyceryl monostearate 1.0Mineral oil (70 Saybolt) 15.0Triethanolamine 0.8Propylenc glycol 5.0Water 69.2Perfume q.s.

100.0 PartsPigments 15-25 Parts

These are elegant emollient preparations with good applicationpropertieson skin. They spreadwell with matte coverageand withoutstreaking or leathering. Acetulan in the anhydrousmakeup acts as adegreasingagent for the waxy vehicle. The lubricant properties ofAmerlate P help to overcome the frictional drag of the high pigmentlevels of these two formulations.

RHEOLOGICAL ACTIVITYLanolin derivatives influencethe rheologicalpattern of emulsionsys-tems in a profound manner. They participate as emulsifiers n the for-mation and stabilization of an emulsionand can also affect developmentof its ultimate viscosity. Such viscosity trends are often thought ofonly in terms of the external phase. Elementary emulsion considera-tions point to crowding of the external phase by the volume of the dis-


8/13


persedphaseand the useof external hydrocolloids s the prime sources fviscosity control. These studies show that the incorporation of lanolinderivatives in the interfacial film is an effective way to modify viscositybehavior and simultaneouslyadd emollient properties.The formulations shown in Table IV utilize Solulan C-24, an O/Wemulsifier,together with cholesterol,a W/O emulsifier, n various ratioswhich determine the viscosity pattern of a cosmetically elegant O/Wlotion. Brookfieldreadingsshow the dramatic influence of slight ad-

Table IVViscosity Changes in O/W Lotion

Cholesterol USP ...Solulan C-24 ...Stearic Acid XXX 3.0%Glyceryl monostearate

(pure) 3.0Mineral oil (70 Saybolt) 25.5Triethanolmnine 1.0Propylene glycol 4.0Water 63.5Observations fter one

month:Appearance at room

temp.Viscosity readings

Brookfield--cps.#3 spindle 3 rpmRoom temp. stability goodIncubator stability good

(42C)

0.5% 0.5% 0.5- 0.5%.. 0.15 0.3 0.75

3.0 3.0 3.0 3.03.0 3.0 3.0 3.0

25.0 25.0 25.0 25.01.0 1.0 1.0 1.04.0 4.0 4.0 4.0

63.5 63.35 63.2 62.75

medium heavy no flow heavy flow medium heavy mediumflow flow flow

23,000 off-scale 39,000 26,000 9,400(solid)good good good goodgood fair good fair

justments in concentrationof Solulan C-24 [ethoxylated (24 moles)cholesterol]on the reduction of the viscosity of the system. Extendedtime studiesof this formula show hat an optimum concentrationof 0.3%Solulan C-24 prevents the undesirable hickening of this formula whilemaintaining ts stability. This antigellingeffect is a very usefulprop-erty whichmay be applied o many lotion systems.

SOLUBILIZATIONTransparent gels involve the use of microemulsionsn modern cos-metic technology. Lanolin derivatives are essential components nmany of these interesting systems n which the dispersedphase is in-visible to transmitted ight (theoretically particle sizeof less han one-


9/13


fourth of the wavelength of light). Extensive studies of this type ofsolubilizationhave been reported previously (6). The following ormu-las (c and d) illustrate someof the transparent gels; in these cases, helanolin derivative promotes stability in the presenceof a large amountof both oil and water phasesat a relatively low surfaetant to oil ratio,important from irritation considerations.

Ernollient Clear Gels (c and d)Solulan C-24 15% Solulan 16 10%Isopropyl myristate 25 Atlas G-1292 10Oleyl alcohol 5 Mineral oil (70 vis.) 20Atlas G-1292 15 Oleyl alcohol 4Propylene glycol 5 Propylene glycol 5Water 35 Hostaphat KL340 4Water 47

Experiencewith transparent colloidal dispersionsndicates that, al-though they are generally considered o be thermodynamically stable,they must be formulated very carefully if they are to survive the tem-perature extremes o which commercialproducts are normally exposed.Aging tests with microemulsions hould ake this into consideration,andthe formulator should examine his experiments closely for changes ntheir physicalstate ndicatedby gradualopacification,ossof consistency,and a lossof their resonantor vibrating character. The latter often ap-pears first and may precedeother adversechanges.

EMULSIFYING EFFECTSThe performance of lanolin derivatives as emulsifiers has been re-ported previously n somedetail (7). More recently these aboratorieshave been concernedwith the participation of lanolin derivatives in as-sociationphenomena related to the construction of emulsion nterfaces.Much of this work has been of an empirical nature, and many formulas

have been developed n which so-called heoretically balanced systems(e.g., HLB) utilizing conventionally paired O/W and W/O emulsifiershave been supplemented by the addition of lanolin derivatives. Forexample,use of one of the Amerchols W/O) together with a Solulan(O/W) will add stability by associatingat the interface with the otherhydrophilic and lipophilic emulsifiers. This can be demonstrated inboth nonionic and ionic systems and, in addition, leads to added bene-fits in terms of improved feel and texture. This work is actually an out-growth of the classical experiments demonstrating the interfacial cou-pling of cholesterolwith anionic emulsifiersof the sodium alkyl sulfatetype (8). Examplesof emulsion ormulas (e, f, and f) having well as-


10/13


sociatednterfaces,with lanolin derivativesas the key auxiliary emulsi-tiers, are given below:(e) Anionic Lotion O/W (g) Nonionic Lotion O/WHair Dressing (f) Cationic Lotion O/W Roll-On Antiperspirant

Waxolan 5.0% Amerchol L-101 5.0% Amerlate P 1. $%Amerchol L-101 4.0 Solulan 98 2.0 Amerehol L-101 3.5Amerlate P 3.0 Cetyl alcohol 1.0 Solulan 98 2.0Stearic acid 2.0 Arlacel 165 4.0 Cetyl alcohol 2.0Mineral oil (70 10.0 Emcol E-607S 0.1 Glycerol 2.0Saybolt) Glycerol 2.0 Polyoxyl 40 stearate 4.0Glyceryl monostearate 1.0 Water 85.9 Veegum HV 1.0Ucon 50 HB 660 5.0 Perfume q.s. Water 38.0Water 68.86 Chlorhydrol, 50% 36.0Carbopol 941 0.15 Alcohol 10.0Triethanolamine 1.0 Perfume q.sPerfume q.s.

Formula e is a heavy bodied lotion with goodgroomingqualities forhair. It behaves like a cream-oil type but is washable and non-oily.The cationic otion f may be used or generalhand and body applicationsor for removing static from hair for good manageability. The roll-ong is a relatively non-tacky system which resists crystallization on theball applicator and depositsa flexible antiperspirant film on skin.SPREADING PROPERTIES

Surface activity can be expressedn terms of spreadingcoefficient(S) calculated from the following equation:S = ?B- 3A- 3'A

where B is the surface tension of water; A surface tension of the oil;and % is the interfacial tensionbetweenoil and water. The followingTable V presents surfaceand interfacial tension data determined onmineral oil solutionsof severalproducts; these data are comparedwiththe calculated spreading coefficients.The higher the value of S, the greater the tendency for the oil tospreadover the water surface. It is interesting o note here that severallanolin derivatives, which do not fit the classicaldescriptionof emulsi-fiers because heir molecular configurations how no hydrophilic-lipo-philic contrast,neverthelesseduce nterfacial tensionconsiderably ndshow correspondingly igh spreading coefficients. This indicates thatthere are other factorswhich may determine he interfacial activity oflanolin derivatives. An example of this is a comparisonof the value ofAcetulan with that of isopropyl myristate: Acetulan demonstrates


11/13


Table VSpreading Coefficients (S)

7A(oil) -AB(oil/water) S(calculated for 7B =72.3 for water)

5% Solutions in mineral oil(70 Saybolt)

Acetulan 32.0 21.2 19.1Amerchol L-101 32.8 7.6 31.9Modulan 32.5 15.0 24.8Polylan 31.7 16.8 23.8Ricilan B 32.6 19.1 20.6Ricilan C 32.4 21.7 18.2Viscolan 31.8 5.7 34.8Isopropyl myristate 31.7 32.9 7.7PEG 400 dilaurate 32.7 0.4 39.2

100% MaterialsAcetulan 32.9 17.2 22.2Isopropyl myristate 30.9 16.7 24.7Mineral oil (70 Saybolt) 32.4 45.3 -- 5.6

depressanteffect on interfacial tension even after dilution to 5% inmineral oil; isopropyl myristate does not show this effect.[[ The ollowingormulash, and ')orbathoils tilizehese rinciplesto promote their spreadingcharacteristicson water. This action of thelanolin derivatives can be fortified, if desired, by the addition of anoil soluble surfactant which will, in turn, promote emulsification ofbath oil throughout the bath water. The above formulas are surfaceorienting. Reducing the surfactant, in this case polyethylene glycol400 dilaurate, favors migration of the dispersedoil droplets to the sur-face of the water.

Emoilient Bath Oilsh i j

Acetulan 5% ......Modulan 5 ......Viscolan ... 10% ...Polylan ...... 3.5%PEG 400 dilaurate 5 5 4.5Isopropyl myristate 25 25 37.5Mineral oil (70 Saybolt) 60 60 54.5

SUMMARYVarious aspectsof studiesconcernedwith the participation of lanolinderivatives in surfacephenomenawere presented. These surfaceactive

effectsare valuable supplementalproperties to the establishedemollientcharacter of these derivatives.


12/13


Data on pigment wetting performance were presented utilizing asimple technique which permits the comparative evaluation of lanolinderivatives in a quantitative manner.The influenceof lanolin derivativeson the rheologicalpattern of emul-sion systemswas illustrated by the viscosity and stability behavior ofthese systems.Solubilizing and emulsifying effects of lanolin derivatives were dis-cussed, and formulas were presented illustrative of the principles in-volved.

Finally, data on the spreadingpropertiesof several anolin derivativesalong with their practical applications were presented.(Received April 21, 1965)

REFERENCES(1) Weitkamp, A. W., J. Am. Chem. Sac., 67,447 (1945).(2) Conrad, L. I., Am. Perfumer, 64, 177 (Sept. 1954).(3) British Patent//965,849; U.S. and other foreign patents pending.(4) Daniel, F. K., Qc. Dig. FederationPaint Varnish Production Clubs, 344, 635 (Sept.1953).(5) Bews, I. C., and Fisk, N. R., Am. Perfumer Cosmetics, 9, 89 (Oct. 1964).(6) Conrad, L. I., Motiuk, K. and Maso, H. F., roc. Sci. Sect. Toilet GoodsAssoc.,29, 14(1958).(7) Conrad, L. I., Am. Perf. 71, 70 (June 1958).(8) Schulman, J. H., and Cockbain, E.G., Trans. Faraday Sac., 36,651 (1940).

APPENDIX

AcetulaneAmerchol L-101Amerlate PModulanPolylanRicilan BRicilan CSoluln 16Solulan 97Solulan 98Solulan C-24Viscolan Waxolan

Raw Materials Used(A) Lanolin Derivatives*

Acetylated lanolin alcoholsLiquid multi-sterol extractlsopropyl lanolateAcetylated lanolinLanolin alcohols linoleateLanolin alcohols ricinoleateAcetylated lanolin alcohols ricinoleateEthoxylated lanolin alcoholsCompletely acetylated, ethoxylated lanolin alcohol-estersPartially acetylated, ethoxylated lanolin alcohol-estersEthoxylated cholesterolLanolin oilLanolin wax

* The above products are manufactured and the Trade Marks are owned by AmericanCholesterol Products, Inc., Edison, N. J.


13/13


Arlacel 165

Carbopol 941Chlorhydrol 50%Emcol E-607-SAtlas G-1292

Hostaphat KL340Microwax (m.p.170F)Ucon 50 HB 0Veegum HVOxy Red

(B) Miscellaneous ingredientsGlyceryl monostearate, acid type, self emulsifying, Atlas

Chemical Industries.Carboxy vinyl polymer, B. F. Goodrich Chemical Co.Aluminum chlorhydroxide complex, Reheis Co., Inc.N-(Stearoyl colamino formyl methyl) pyridinium chlo-ride, Emulsol Division, Witco Chemical Co.Ethoxylated hydrogenated castor oil, Atlas Chemical

Industries.Tertiary ester from o-phosphoricacid and lauryl tetra-glycol ether, Hostachem Corporation.Microcrystalline hydrocarbonwax, white, 170F m.p.,Bareco Wax Co.Polyalkylene glycol, Union Carbide ChemicalsConpany.Magnesium aluninum silicate, R. T. Vanderbilt Co.Purified grade of ferric oxide, Whittaker, Clark and

Daniels.

Documents

1966_conrad Et Al._surface Modifying Effects of Lanolin Derivatives (Jscc)