1. Development And Evaluation Methods
For Polymeric Films
Prepared By-Vijaylaxmi Yadav
DEPT- Pharmaceutics
Y.B.CHAVAN COLLEGE OF PHARMACY
AURANGABAD
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2. INDEX
 Introduction
 Definition
 History
 Classification
 Properties
 Polymerization methods
 Development methods
 Evaluation techniques
 References
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3. Introduction
POLYMERS
Polymers also known as macromolecules, are very large
molecules consisting of many repeating units and are formed by a
process called polymerization, which links together small
molecules known as monomers. The monomers can be linked
together in various ways to give rise to linear polymers, branched
polymers (thermoplastic material), or cross-linked polymers
(Billmeyer,1971).
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4. HISTORY (Dubois,1972)
Before 15th century-animal skin (polymer) used by early man
to cover his body.
In 15th century -Christopher Columbus found Ruble or Yen (a
solid mass collected from the exudates of a tree, called weeping
wood).
In the mid 19th century-Christian Schonbein, a Swiss scientist
introduced gun cotton, a nitro derivative of a natural polymer
cellulose.
In 19th century- Leo Baekeland developed Bakelite from
phenol and formaldehyde
In 1912- Jacques Brandenburger introduced cellophane.
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5. CLASSIFICATION (Billmeyer,1971)
Based on origin :
Natural :- e.g. cotton ,silk , wool, rubber,leather,cellulose rayon etc.
Synthetic :- e.g.polyethlene , PVC, nylon, terylene.
Based on backbone chain :
Organic polymers :- made of carbon toms, e.g. PE , PVC ,nylon.
Inorganic polymers :- e.g. glass ,silicon, rubber
Thermoplastic :- soften on heating and stiffen on cooling .e.g. PVC
Thermosetting polymers :- melamine formaldehyde, urea
formaldehyde.
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6. Based on its ultimate form and use :
Plastics :- e.g. PE,PVC,PVP,PMMA
Elastomers :- e.g. natural rubber, synthetic rubber, silicone
rubber.
Fibers :- e.g. nylon ,terylene
Liquid resins:- e.g. epoxy adhesives and polysulphide sealant
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7. Properties of polymers
• High Tensile strength
• Light weight
• Good flexibility
• Special electrical properties
• Resistance to chemicals
• Ability for quick and mass production
• Can be fabricated into complex shapes
• Good Swelling Bhaviour
• Bond objects , seal joints, fill cavities, bear loads
In fact, anything from clothing the naked to powering a
space vehicle to even replacing a human organ !
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8. POLYMERIC FILMS
Processing/development techniques :-
It involves conversion of monomers or bulk polymer into
the desired useful form, various methods are :-
1) Film casting
2) Melt fabrication/Bubble blowing
3) Calendring
4) Melt press
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9. Film casting :-
Polymer dissolved in a
suitable solvent to form a
viscous solution, spread on
a flat non-adhesive
surface, solvent evaporates
slowly and the film is
peeled off slowly. At lab.
scale films thickness
controlled by gardener
knife.
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10. Preparation of films containing nano-particles (Atul et al 2010)
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11. BUBBLE BLOW TECHNIQUE
Films can be produced by extrusion through a suitably shaped die
or by first extruding a tube and then expanding the hot tube by
compressed gas into a tube of thin film.
Bubble blow technique 11

12. CALENDERING
It consists of metal roller
rotating in opposite to each
other. The gap between the
rollers that determines film
thickness. Polymeric material is
fed between the rollers(elevated
temp.)and the sheet emerging
from the rollers are cooled by
passing through cooled rollers.
The sheets are finally wound up
in rolls .
For thin films, a series of
rollers with diminished gap
between them is used.
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13. MELT PRESSING
Polymer is placed between
two metal plates and the
plates then placed between
two heated plates in a press.
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14. EVALUATION TECHNIQUES
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15. The various methods for polymeric film evaluation are :-
(Wong Fun et al1999,Atul et al ,2010)
1) Physical appearance
films are evaluated for color, clarity, flexibility and
smoothness.
2) Film thickness
Micrometer and screw gauze :- thickness measured at 5
different locations (centre, 4corners), mean thickness is
calculated and % deviation is determined. If deviation >5%
rejected.
3) Uniformity of weight(B.P.)
Film is cut into10 strips of 1cm 2 each and their average
weight is calculated, % deviation determined. 15

16. 4) Tensile strength
for polymer characterization :-
Strain = Tensile strength (TS)
Elastic modulus(EM)
TS(kgmm-2 ) = Force at break(kg)
Initial cross-sectional area of sample (mm2)
ES(kgmm-2 ) = Force at corresponding strain(kg) X 1
Original length (mm) area(mm2)
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17. Polymer Tensile Elastic Elongation at
nature strength modulus break
Soft and weak low low Low
Hard and brittle moderate high low
Soft and tough moderate low high
Hard and tough high high high
Strain defines the mechanical quality of the film
More the strain strong and elastic is the film.
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18. 5) Film folding endurance
Five films selected randomly and folded repeatedly until it
shows any crack or break. The number of times the film could
be folded without breaking or cracking gave the value of folding
endurance.
6) Swelling behaviour
In medias like-
distilled water
simulated saliva solution (phosphate buffer saline)
Swelling index = wt – w0 where,
w0
wt  weight of film at time t
w0 weight of film at time t = 0
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19. 7) Surface pH
The prepared films are left to swell in double distilled water for
two hrs with stirring.
The surface pH was measured by means of pH paper placed on
surface of swollen film. The mean of two reading is recorded.
8) Surface topography
using- DSC
SEM
9) Bioadhesive strength
Texture analyzer
10) Dissolution test
As per individual monograph
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20. 11) A rupture test
Performed by using the compression mode and a film support ring
with 5 mm stainless steel ball probe. A circular strip film with an area of
3.88 cm2 was used. The force needed to break the film was calculated.
The average and standard deviation for three samples were also
recorded.
12) Erosion study
The polymeric films were cut into a size of 10 mm 10 mm. The
erosion degree of the polymeric film was determined by placing the
polymeric film in 25 ml sol. (pH 4.0) on 20 rpm of Orbital Shaker . At
predetermined time intervals, a sample was removed and completely
dried in the oven at 60 C for 24 h to determine its weight. Percentage
remaining was calculated by using parameter -
100 − (Wp − Ws) 100/ Wp
Where, Wp and Ws are the original weight of the film and the weight of
the dry film after erosion, respectively. 20

21. 13) Contact angle measurement
A contact angle is used as an indication of degree of wetting. The higher value
of contact angle means the less degree of wetting. It was also reported that
contact angles are correlated to the work of adhesion, which represents strength
of mucoadhesiveness. As shown in the degree of contact angle decreased as
Carbopol concentration in the films increased. The film with the highest
concentration of Carbopol (i.e., the composition of C:H:P = 2:1:1) showed the
lowest contact angle, which means having high wetting capability and work of
adhesion.
Measurement of contact angel of polymeric films. Each data point represents the
mean ± S.D. of three replicates.
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22. 14) Moisture uptake study
The film was weighed and kept in a desiccators containing calcium
chloride at 400C in a drier for at least 24 h or more until it showed a
constant weight.
The moisture content was the difference between the constant
weight taken and the initial weight and was reported in terms of
percentage (by weight) moisture content.
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23. 15) Antibacterial Activity
The bacteriostatic effect of the films containing drug can be
determined by agar-plate diffusion assay. A cotton swab charged
with S.aureus (ATCC 25923), klebsiella pneumonia (ATCC
13883), Escherichia coli (ATCC 25922) and Proteus vulgaris
(ATCC 13315) suspension (106 CFU/ml) were inoculated on
plates and bacteria was spread evenly over the surface of the
Luria agar media. These plates were incubated at 37 C for 24
hrs. and the zone of inhibition were measured and recorded.
This procedure was repeated until no zone of inhibition was
seen (> 10 mm).
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24. 16) Drug content
Drug content (%w/w) = mass of drug x 100
mass of film
17) Accelerated stability testing
As per ICH guidelines (ICH Q1A[R2])
At 400c + 20c and 75 + 5% RH
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25. References
1) Billmeyer , F.W. ,Textbook of Polymer Science, Wiley Interscience, New
York,1971
2) Kumar, A. and Gupta, S.k., Fundamentals of a polymer Science and
Engineering, Tata McGraw-Hill , New Delhi,1978
3) Dubois, J.H., Plastics History- USA,Cahners,Batson,1972
4) Wong Fun Choy et al ,Polymeric film as a vehicle for Buccal
delivery, Jpharm Pharmaceut Sciences, vol-2,1999 page no.53-61.
5) Gaikwad Atul et al, Design and Development of HPMC based Polymeric
Film of Enalpril Maleate, International Journal of Pharma Tech
Research, vol-2,no..1, 2010,page no.274-282.
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26. Thank you !!!!!
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