Glass Containers for Pharmaceutical Packaging

A. A. Joshi.

GLASS AS A PACKAGING MEDIA

• GLASS BOTTLE - CONTAINER OF CHOICE FOR PACKAGING.

• IMPERVIOUS TO MOISTURE & GASES.

• INERT.

• PROVIDES GOOD PROTECTION.

GLASS CONTAINERS

RAW MATERIALS

TYPE I TYPE III

FLINT AMBER FLINT AMBER

SAND 68% 65% 72.5%

ALUMINA 5.5 6 2

SODIUM OXIDE 10 9.5 14

BORIC OXIDE 10 10 0.5

CALCIUM OXIDE 1 0.5 11.5

Glass container making

• 15-30% cullets- broken glass are added which helps in melting the glass in the furnace.

• Colorless glass is obtained by using decolorizers like selenium or cobalt oxide.

• Reducing Iron content to below 0.3% can limit green tinge to acceptable level.

• Amber colour glass is obtained by adding iron & manganese oxide.

Glass container making process

• Glass container making has 4 stages –

• 1. Glass gathering

• 2. Parison Forming

• 3. Transfer

• 4. Blowing

DEFECTS IN GLASS BOTTLES

• BOTTLE MANUFACTURING INVOLVES HIGH TEMPERATURE - 1400 C.

• BOTTLES COMING OUT OF MOULD AT HIGH TEMPERATURE ARE EXPOSED TO ROOM TEMPERATURE AND ARE THUS SUBJECTED TO THERMAL SHOCK, SETTING STRESSES WITHIN ITS BODY.

Annealing to release stresses

• Glass containers receive a thermal shock as it comes out of the mould & placed on a conveyor which is at room temperature, as inner side is hot while outer side is exposed to room temp.

• To release the stresses built in the container body, it is passed though a tunnel called Annealing lehr which gradually reduces the temp. from about 550 C at the beginning of the tunnel to near room temp. at the other end of the long tunnel.

Glass container defects

• Mould Design- cavity wears out due to fluctuation in Temperatures bet 450-600 C as red hot glass drops in to the mould which is at near room temp. & then parison is transferred to another mould for blowing

• This results in bottle capacity variation & other defects

• GLASS IS ONLY AS STRONG AS ITS SURFACE.

• SCRATCHING, BRUISING CAUSE SIGNIFICANT REDUCTION IN THE STRENGTH OF CONTAINER.

• BREAKAGE IS REDUCED TO LESS THAN 1% BY SHRINK PACKAGING FROM OVER 2% WITH CFB PACKAGING IN ONE CO.

COATNGS ON GLASS BOTTLES

• COLD END / HOT END COATINGS TO IMPROVE DURABILITY.

Importance of Glass • Glass is preferred as packing

material in pharmaceutical industry mainly because:

1. Glass is chemically inert and this property enables us to pack the products without any risk of reaction or spoilage.

2. Compatible with majority products.

3. Not allow gases, moisture and other odour to penetrate through its walls.

.

4.Transparent nature allows visual inspection of filled products.   

5. Can be made in any shape and size as desired.

6.The basic raw materials for making glass are silica sand, soda ash and lime, which are readily available in India as a natural source.

So procurement of materials is not a problem.

Importance of Glass ...cont

Importance of Glass.. cont

7. It is ideal for running on high speed automatic packing lines.

8. It can be made pilfer proof by using cap seals.

9. 100% Recycling is possible hence environment friendly.

  Types of Glass Containers

All bottles used in liquid packing are normally of soda lime glass of USP Type III. However, if high resistance glass is required for the product, for example, injectables and transfusions, Borosilicate USP Type I glass is being used. USP Type II is same as the Type III but inside of the glass is coated, which reduces the alkalinity level.

TYPE OF CONTAINERS

I - NEUTRAL / BOROSILICATE

II - INNER SURFACE COATED

III - LIMITED ALKALINITY

Type II –Surface coated glass

• Glass bottles type III are treated in Annealing lehr by adding Amonium sulphate tablet in each bottle or injecting sulpher dioxide.

• By this treatment excess surface alkalinity is neutralized.

Selection of a ContainerGlass container selection for a pharmaceutical product will depend mainly on the product properties and container availability.

The product properties to be taken into account will be such as

1) Nature of product

i.e. acidic /neutral /alkaline. –

Selection of a Container...cont

2)Frothing, effervescent, releasing gases on storage, requiring inert atmosphere.

Selection of a Container..cont

 3) The processes the container will

undergo such as washing sterilization, hot or cold filling, method of sealing & type of

closure.

Selection of a Container...cont

3)Frothing, effervescent, releasing gases on storage, requiring inert atmosphere.

4)Physical properties such as specific gravity, density.

5)Light and heat sensitive ingredients.

6)Shelf life - After filling, storage, exposure to heat, cold, moisture, and light exposure.

Selection of a Container..cont

 7) The processes the container will

undergo such as washing sterilization, hot or cold filling, method of sealing & type of

closure.

8) Container size and shape, design, narrow mouth OR wide mouth, Tall OR short in height.

Selection of a Container..cont

  9)  Colour - Amber or Flint.

10) Chemical Durability.

11) Types of machinery used for washing, filling, sealing labeling

etc.

PACKAGING OF LIQUIDS.

• PACKAGING MACHINES - 1) PRODUCT FILLING. 2) CONTAINER CLOSING / SEALING. 3) CONTAINER LABELLING. 4) OVERPRINTING / CODING.

• CARTONING / SHRINK PACKAGING.• PACKAGING IN SHIPPER (CASE

PACKER.)

Standard Containers   The products such as expectorant,

cough formulas, drops and such other products have been filled into conventional type of bottles but with varying capacity. These types of containers are mainly in 22 mm and 25 mm pp (pilfer proof) neck.

Standard Containers ..cont

  In selection of these packs the

quantum of off take is another factor. In large volume products selection of a simple type of bottle help in packing of the product. This type of bottles can be filled, sealed and labeled with machinery readily available

Non – standard containers

 

  The different size and shape containers

are selected mainly for the products, which an organization wants to be identified in the market place OR a brand image needs to be established. These are either a unique type or fancy shape containers that attract the consumer. These types of products fall under the category of multi vitamins, tonics, food supplements and nutraceuticals. e.g. Santivani of Novartis, RB tone of Medley etc.

   FinishNeck

Bead or Collar

Shoulder

Push Up

Bottom

InSweep

Bore

Contactpoint

Heel

Various Parts of Container

Finish:- This is the top of the container above the neck ring parting line . I t includes : Sealing surf ace, Bore, Bead or collar.

The sealing device is in the fi nish, also the bore or mouth f or fi lling and emptying. The bead or collar s used to assist o transf erring the parison into the blow mold.

Neck:- The part which extends f rom the parting line to the curve at the base of the neck.

Shoulder:- This extends f rom the base of the neck to the straight part of the body.

Body:- The main part of the container which holds the product.

GLASS BOTTLE SHAPE.

• SHAPE OF THE BOTTLE AFFECTS BOTTLE PERFORMANCE. 1) LONG NECK BOTTLES ARE DIFFICULT TO FILL. 2) TALL BOTTLES ARE UNSTABLE ON HIGH SPEED MACHINE. 3) CYLENDRICAL BOTTLES ARE STRONGER & GOOD FOR STACKING.

BOTTLE DIMENSIONS.

• IMPORTANT DIMENSIONS ARE - 1) BODY DIAMETER. 2) NECK DIMENSIONS. 3) HEIGHT.

• BOTTLE CAPACITY.

TOLERENCES IN GLASS BOTTLE.

• TOTAL HEIGHT - +/- O.6 = 1.0 MM.• DIAMETER - +/- 0.5 = 1.0 MM.• VERTICALITY - 0.3 + 0.01 HEIGHT.• CAPACITY - +/- 5 ML FOR 500ML

& ABOVE.

• 10% REJECTION IN BOTTLE MFG. IS NORMAL.

Siliconised vials

• To prevent powders sticking to the side walls, vials are silicon coated & dried in the oven.

COLOURED BOTTLES.

• COLOUR OF BOTTLE INFLUENCE PRODUCT PROTECTION. 1) TRANSPERENT ARE GOOD FOR EASY INSPECTION. 2) AMBER COLOUR FILTERS CERTAIN LIGHT RADIATIONS & HELPS PREVENT PRODUCT DEGRADATION.

PRINTED GLASS BOTTLES

• IT IS POSSIBLE TO PRINT GLASS CONTAINERS WITH CERAMIC INKS . THIS MAY REDUCE THE LABELLING OPERATION AND ITS COST.

• PRINTING OF MULTICOLOUR GRAPHICS IS ALSO POSSIBLE.

IMPORTANT TESTS  

  The glass bottles manufacturer and user pharmaceutical organization normally have a common understanding about the Accepted Quality Levels (AQL). The defects are categorized as Critical, Major and Minor.

AVERAGE QUALITY LEVEL (AQL)

• CRITICLE DEFECTS - CONTAMINTES PRODUCT WITH LOSE GLASS PARTICLES - 0.4%.

• MAJOR DEFECTS - WHICH CAUSE LOSS OF PRODUCTION - 0.6 TO 1 % .

• MINOR DEFECTS - NO FUNCTIONAL PROBLEM BUT POOR APPEARANCE - 4%.

IMPORTANT TESTS  

  1. Critical dimensions (height, diameter, neck finish etc.)  2. Capacity and weight.  3. Wall thickness.  4. Thermal shock test  5. Limit of alkalinity.  6. Verticality test.  7. Annealing test.  8. Visual defects.

TESTS FOR GLASS

• ANNEALING RELEASES THE STRAIN IN GLASS.

• 1) ANNEALING TEST - TESTED BY PASSING POLARISED LIGHT THROUGH GLASS AND VIEWING THROUGH POLARISCOPE - SHOULD NOT SHOW PLAY OF COLOURS - STANDARD DISC NO.1 TO 5 USED.

• OPTICAL GLASS TO PASS WITH DISC NO.1.

• FOR COMMERCIAL GLASS - DISC NO.3 PASSING IS OK.

• 2) RING SECTION ANALYSIS IS DONE TO TEST HOMOGENITY OF GLASS – DONE BY CUTTING 1 CM HIGH RING FROM THE CONTAINER AND VIEWING THROUGH MICRO POLARISCOPE.

3) THERMAL SHOCK TEST -

• FOR TESTING, HOT AND COLD WATER IS USED.

• FOR TYPE I, THERMAL SHOCK OF 60OC. IS GIVEN.

• FOR OTHER TYPES, THERMAL SHOCK OF 45OC IS GIVEN.

• THIN WALLED CONTAINERS HAVE BETTER RESISTANCE .

• BOROSILICATE GLASS HAS BETTER THERMAL SHOCK RESISTANCE THAN SODA GLASS.

• 4) PRESSURE TEST -

• DONE FOR BOTTLES USED FOR LIQUOR, SODA WATER, ETC.

• PRESSURE IS APPLIED IN THE CONTAINER FOR 1 MINUTE.

• AT HIGHER TEMPERATURE PRESSURE RESISTANCE IS REDUCED i.e. PR. REST. AT 30OC > PR 60OC.

5) IMPACT TEST -

• FOR CONTAINER UNDERGOING MULTIPLE HANDLING e.g. MILK & BEVERAGE BOTTLES.

• STEEL BALL OF 400 GMS IS DROPPED FROM THE HEIGHT OF 10 CMS. FOR MILK BOTTLE, THE BALL IS DROPPED 3 TIMES ON THE SAME SPOT AND BOTTLE SHOULD NOT BREAK.

6) DENSITY TEST -

• USES MIXT. OF MONOCHLOROBENZENE AND XYLENE OF 2.5 DENSITY.

• TEST AND CONTROL (REFERENCE) SAMPLES ARE DROPPED IN THE TEST TUBE WITH THE MIXT. AND HEATED IN A WATER BATH.

• BOTH THE PIECES TO SINK SIMULTANEOUSLY.

7)Alkalinity- Type of Glass-USP

• By titrating extracts of distilled water with N/50, H2SO4

• Type I 1ml

• Type II 0.2 ml for up to 100 ml bottle

• Type III 8.5 ml

• Type IV 15 ml

REDUCED BREAKAGE OF GLASS CONTAINERS

• THE GLASS INDUSTRY IS INCREASINGLY ADOPTING SHRINK/STRETCH WRAPPING TECHNIQUES FOR PACKAGING OF EMPTY GLASS VIALS/BOTTLES.

• THIS HELPS IN REDUCED BREAKAGES IN TRANSIT AND ALSO AVOIDS CONTAMINA-TION DURING STORAGE.

CLEAN GLASS CONTAINERS

• EARLIER OWING TO CONTAMINATION DURING STORAGE AND TRANSPOR-TATION, GLASS BOTTLE USERS WERE REQUIRED TO WASH THE BOTTLES BEFORE USE.

• OWING TO IMPROVED HOUSE-KEEPING AND (SHRINK) PACKAGING, THE USER INDUSTRY CAN USE BOTTLES FOR PRODUCT FILLING DIRECTLY.

LIGHT WEIGHTGLASS CONTAINERS

• LIGHT WEIGHT GLASS -- WITH IMPROVEMENT IN GLASS CONTAINER TECHNOLOGY, UNIFORM DISTRIBUTION OF GLASS IN THE CONTAINER IS POSSIBLE.

• THIS HAS RESULTED IN REDUCING THE WEIGHT OF THE GLASS BOTTLES WITHOUT SACRIFICING THE STRENGTH.

COST SAVING

• REDUCE NECK SIZE - PARTICULARLY FOR LIQUID PRODUCTS, IT IS SUGGEST-ED TO REDUCE THE NECK SIZE FROM 25 MM OR MORE TO SAY 22 MM.

• THOUGH THIS DOES NOT REDUCE THE COST OF BOTTLE, IT HELPS IN REDUC-ING THE SIZE OF CAP AND MEASURING CUP ETC. WHICH MAY RESULT IN COST SAVING.

BOTTLE CLOSURE.

• 1) METAL CAP -ALUMINIUM / TINPLATE( FOR PILFER-PROOOFING).

• 2)WADING - CORK / EXPANDED POLYETHYLENE.(FOR GOOD SEALING).

• 3) LINERS - LDPE / PVC. ( PREVENT CONTAMINATION FROM WADDING).

CHILD RESISTANT CLOSURES

• FOR SOME PRODUCTS, IT IS DESIRABLE TO HAVE A CHILD RESISTANT CLOSURE.

• IN SOME COUNTRIES IT IS MANDATORY FOR SOME OF THE SCHEDULED DRUGS.

SENIOR CITIZENFRIENDLY CLOSURES

• THERE IS A TREND TO USE CLOSURES WHICH ARE RELATIVE-LY SIMPLE & EASY TO OPEN PARTICULARLY FOR PRODUCTS MEANT FOR SENIOR CITIZENS.

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