studies on phthalic acid

8/3/2019 Studies on Phthalic Acid

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Welcome

ToThe Seminar Talk


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STUDIES ON PHTHALIC ACID-PROPANE-1, 2-DIOL-GLYCEROL

CO-POLYESTER AS AN ENTERIC COATING MATERIAL.

Presented byMd. Moinul Haque

M.Sc (Thesis), Exam. 2006Examination Roll No. 02115054

Department of Applied Chemistry and Chemical Technology,University of Rajshahi.


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OBJECTIVE OF THE PRESENT WORK

The polymers, which are being produced synthetically, are not erodable in nature.

For non-biodegradability they are stable for long time and are imparting various

inconveniences, producing environmental pollution.

Recently considerable interest is being focused on the development of

biodegradable polymers for specialized applications. Such as controlled release

formulation, insecticide and pesticide carriers, as well as non-toxic surgical implant

materials.

Our aim is, therefore, to develop novel commercially viable polymers, specifically

designed to degrade under controlled biological conditions. In this connection, we

have chalked out to synthesize biodegradable polymers from phthalic acid, propane-

1, 2-diol and glycerol.


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EXPERIMENTAL

EQUIPMENTS

The following equipments were used in the investigation

Round bottom flask.

Dean stark apparatus.

Desiccators.

Vacuum pumpType: Edward High Vacuum Crawly F-550 (England).

5. Electrical balance

Type: H-51, Metter Instrument Co. (Switzerland).

6. IR Spectrophotometer

Type: FTIR-470 (400-4000 cm-1 wave no.) Shimadzu, Japan.

7. pH meterType: pH-3C, Rex, China.

Melting point measurement machine

Type: PIC- CLARITON, India.

8. Tablet Dissolution Tester USP (XXIII).

Type: ELECTROLAB TDT-01, Shimadzu, Japan.,

etc.


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SYNTHESIS OF POLYMER

Polymer from phthalic acid and propane-1, 2-diol along with 1%, 2%, 3%, 4%

and 5% glycerol as crosslinking agent on the basis of total weight respectively

was synthesized by Dean-Stark Apparatus using Ferric chloride

(approximately 0.4% of the total weight) as catalyst and o-xylene as the

reaction medium at temperature 137-141oC for about 5 hours. The expected

reaction of the co-polyester is -

COOH

COOH

CH2 CH CH3

OH

HO

C

O

CO

O

CH2 CH

CH3

O

FeCl3

+

PhthalicacidPropane-1,2-diol

Anhydrous

n

+

Phthalicacid-propane-1,2-diol-Glycerol Copolyester

2n-1 H2O

n n


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PURIFICATION OF POLYMER

Polymer formed as such, however, be contaminated with the

unreacted monomer, initiator, low molecular weight polymer, solvent

and hence, need to be isolated and purified.


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CHARACTERIZATION OF PHTHALIC ACID-

PROPANE-1, 2-DIOL-GLYCEROL CO-POLYESTER

vM nM

1.IR Spectra

Ester linkage appeared at 1252.5 Cm-1 region

2. Molecular weight determination

>


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3. SolubilitySolubility of PPGC in various organic solvents at theambient temperature such as acetone, ethyl acetate,

acetic acid, and mixed solvent (toluene: ethanol, 1:3) are

good solvents. Ethanol, rectified sprit, chloroform are poor

solvents and diethyl ether, xylene, benzene carbon tetrachloride and water are non-solvents.


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4.1 Swelling behavior in water

0

20

40

60

80

100

120

0 20 40 60 80 100

Swelling time (Hours)

%ofSwellinginwater

Sample-I(1%

glycerol)Sample-II(2%

glycerol)Sample-III(3%

glycerol)Sample-IV(4%

glycerol)Sample-V(5%

glycerol)

Swelling behavior of PPGC in water at the ambient temperature.


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0

20

40

60

80

100

120

0 20 40 60 80 100Swelling Time (Hours)

%ofSwelling

inEthanol

Sample- I

(1%Glycerol)

Sample-

II(2%Glycerol)

Sample- I

II(3%Glycerol)

Sample- IV

(4%Glycerol)

Sample- V

(5%Glycerol)

Swelling behavior of PPGC in ethanol at ambient temperature.

Ethanol > Water

4.2 Swelling behavior in ethanol


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5. Hydrolytic test

Degrade in basic solutions (pH = 7.149.16).

6 Melting point

The melting point of the co-polyester is 83-89oC.

7. DensityDensity of the co-polyester at 31OC is 1.42 g / c.c

8. Elemental analysis


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9. Soil degradation test

0

20

40

60

80

100

120

0 20 40 60 80

Time (days)

%

ofwe

ightloss

SoildegradationofPPGC atnormalweatheringcondition.


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PPGC as an enteric coating material

Medium:

Simulated gastric fluid (pH 1.2)

Simulated intestinal fluid (pH 7.4)

Temperature: 37 C (Body Temp.)

Time: Two hours in simulated gastric fluid (Samples Withdraw at 30 min).

intervals)

One hour in simulated intestinal fluid (Samples Withdraw at 15 min. intervals)

Main instrument used:

Tablet dissolution tester (Model : usp type II, Electrolab-04)

UV-Spectrophotometer (Model: Shimadzu UV- 1200)

Absorbance measured at: 274 nm.


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0

10

20

30

40

50

30 40 50 60 70 80 90 100 110 120

Time (min.)

%ofdrugrelease

core

tab1

tab2

tab3

tab4

tab5

Percentage of drug release from diclofenac sodium

core and coated tablets in simulated gastric fluid

(pH=1.2)


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0

30

60

90

120

135 150 165 180

Time (min)

%ofdrugrelease

CoreTab-1Tab-2Tab-3Tab-4Tab-5

Percentage of drug release from diclofenac sodium core and coated tablets in

intestinal fluid (pH=7.4).


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0

20

40

60

80

100

120

0 30 60 90 120 150 180

Time (min.)

%ofdrugrelease

Coated

Core

pH= 1.2

pH= 7.4

Percentage of drug release from diclofenac sodium core and

coated tablets (coated by PPGC) in simulated gastric fluid

(pH=1.2) and in simulated intestinal fluid (pH-7.4)


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CONCLUSION

This co-polyester (PPGC) remained intact in gastric fluid (pH=1.2) but

gradually degraded in intestinal fluid (pH=7.4). It has been found that, in

gastric fluid the polymer did not release till two hours but in intestinal fluid it

gradually release within 45 minutes. So PPGC has investigated as an enteric

coating material on Diclofenac Sodium (DS) core tablet and results according

to B.P. have been obtained. Toxicological test of the co-polyester is yet to be

performed. If the co-polyester be proved to be non-toxic it might be usable as

an enteric coating material.


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Thank You All

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