FORM 2
THE PATENTS ACT (39 OF 1970)
COMPLETE SPECIFICATION (See section 10)
1. Title of the invention: "Synthesis and characterization of novel di-azo cross-linked polymer for colon specific delivery".
2. Applicant-
Sanjay Baburao Wagh
Martru Darshan, Opp.Vasant market, Old Gangapur Naka, Nashik-422005, Maharashtra, India
Nationality: Indian
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.
3. Preamble to the description
Complete
The present invention deals with colon targeted acrylate polymer having azobenzene-4,4'-dicarboxylic allyl ester & azobenzene-4,4'-diacetic allyl ester, as core linker. The invention also provides methods for the production of these polymeric compounds and a method of characterization of these polymeric compounds in animal models..
4. Description of the invention:
Field of invention: The invention relates to the field of novel di-azo cross-linked polymer for
colon specific delivery.
Background of invention: The colon is liable to numerous pathological conditions, such as Constipation, Crohn's disease, ulcerative colitis, carcinoma & infections, Inflammatory Bowel Disease, Protozoal diseases, Chronic pancreatitis, Pancretactomy and Cystic fibrosis, Diverticuliti setc. Recommended treatment includes the administration of anti-inflammatory drugs, chemotherapeutic agents and / or antibiotics, which must be released in the colon. From the medical point of view, it is also useful to have dosage forms that are able to specifically release drugs, such as peptides, proteins, vermifuges & diagnostic agents in the colon due to its capacity to absorb these drugs. Therefore the search for an effective release pattern of required drug in treatment of complete spectrum of symptoms of colonic disease is still progressing on many fronts.

Object of the invention: Object of the invention is to identify, synthesize & characterize novel and specific drug delivery carrier compound like di-azo polymer with better efficacy and fewer side effects as compared to existing anti-psychotic agents.
A summary of the invention: The present invention deals with colon targeted acrylate polymer having azobenzene-4,4'-dicarboxyIic allyl ester & azobenzene-4,4'-diacetic allyl ester, as core linker. The invention also provides methods for the production of these polymeric compounds and a method of characterization of these polymeric compounds in animal models.
A brief description of the accompanying drawing: The drawings in the sheet consists of structural formulas of the claimed compound (I), (II) and synthetic scheme for the same (III), and (IV) respectively.
Detailed description of the invention: The present invention is concerned with compounds having the formula I (refer sheet I) & formula II (refer sheet II) as colon specific delivery agents (polymers) for treatment of humans having colonic diseases. The site of action at colon offers the distinct advantages of neutral pH, increased transit time, less digestive enzymatic activity and greater responsiveness to absorption enhancers. This enables the visualization of this distal part of the GIT as a site for delivery of various drug molecules including proteins and peptides. For local pathological condition of the colon, colon specific drug delivery not only increases the bioavailability of the drug at the target site, but also reduces the dose to be administered and reduce the adverse effects. Rational for the Development of Oral Colon Targeted Drug Delivery is treatment of local pathologies & less enzymatic activity, chronotherapy (asthma, hypertension, cardiac arrhythmias, arthritis or inflammation), greater responsiveness to the absorption enhancers, site for delivery of delicate drugs (Proteins and Peptides), oral delivery of vaccines as it is rich in lymphoid tissue.
This is also having advantages like drug directly available at the target site, decreased dose to be administered, decreased side effect and improved drug utilization. In the present study we have designed polymeric compounds to be active carrier for colon specific delivery without causing serious side effects which will degrade microbially in colon. The azoreductase enzyme from the human colonic bacteria degrades di-azo bond from the cross-linked polymer and reduces to amine through amide formation. Taking all above facts in consideration, we have designed the stated polymeric compounds. We have synthesized azobenzene-4,4'-dicarboxylic allyl ester (linker I) & azobenzene-4,4'-diacetic allyl ester (linker II), as core linkers and cross linked acylate monomers to synthesize polymer.
The target compounds (linker I) was synthesized starting from p-nitro benzoicacid (a), was converted to azobenzene-4,4'-dicarboxylic acid (b) by reacting with D-glucose & Sodium

hydroxide, which further upon reacting with thionyl chloride catalyzed acid chlorination gave azobenzene-4,4'-dicarboxylic acid chloride (c), which was converted to azobenzene-4,4'-dicarboxylic allyl ester (d) as our targeted compound linker I by treating with sodium salt of allyl alcohol (prepared by reacting allyl alcohol with sodium metal). Further the target compounds (linker II) was synthesized starting from p-nitrophenylaceticacid (e), was converted to azobenzene-4,4'-diacetic acid (f) by reacting with D-glucose & sodium hydroxide, which further upon reacting with thionyl chloride catalyzed acid chlorination gave azobenzene-4,4'-diacetic acid chloride (g), which was converted to azobenzene-4,4'-diacetic allyl ester (h) as our targeted compound linker II by treating with sodium salt of allyl alcohol (prepared by reacting allyl alcohol with sodium metal). The structures of the compounds were established by spectral and elemental analysis. After that these linkers are incorporated in acrylic monomers (methyl methacrylate & butyl methacrylate) to form di-azo cross linked polymers by bulk polymerization and varying linker amount. Further these polymers were coated on capsules containing drug like budesonide by deep coating method and characterized & evaluated for organoleptic, disintegration & dissolution studies. Lastly from the obtained results were applied for zero order, first order, Higuchi & korsmayer Peppes models for drug release pattern study.
EXPERIMENTAL PART (A] Preparation of linkers
1) Synthesis of I Crosslinking agent Azobenzene-4,4'-diacid allyl ester
Azobenzene-4,4'-dicarboxylic acid:Thirteen grams of 4-nitrobenzoic acid (79 mmol) was heated in a solution of 50 g of sodium hydroxide in 250 ml of water at 50°C. A solution of 100 g of glucose in 150 ml of water was added slowly at this temperature with occasional shaking. The reaction mixture was then cooled to ambient temperature and aerated for 8 hr with vigorous stirring until orange-colored crystals were formed. The mixture was acidified with dilute acetic acid; then the liberated diacid was filtered, washed with water and dissolved in hot potassium carbonate solution to get an orange-colored solution. This solution was concentrated to get orange-colored crystals of potassium salt of diacid. On acidifying with dilute acetic acid, rose-colored azobenzene-4,4'-dicarboxylic acid was obtained.
Azobenzene-4,4'-diacid allyl ester: The synthesized Azobenzene-4,4'-dicarboxylic acid (3gm) was refluxed with excess of thionyl chloride for 10 hrs. The excess of thionyl chloride was distilled off to get azobenzene-4,4'-dicarboxylic acid-chloride. Also sodium salt of allyl alcohol was separately synthesized by reacting 1 mole of allyl alcohol with 2 moles of sodium metal. Then azobenzene-4,4'-dicarboxylic acid-chloride is dissolved in 1,4-dioxane and refluxed with sodium

salt of allyl alcohol for 3-4 hrs. Finally the 1,4-dioxane layer was decanted & precipitate was filtered to take filtrate & concentrated to get solid product. Progress of reaction was monitored by using pre-coated TLC plates and structure was confirmed with IR spectroscopy.
2) Synthesis of 2nd Crosslinking agent Azobenzene-4,4'-diacetic acid allyl ester:
p-Nitrobenzylcyanide: In a round-bottomed flask, with a stopper, a dropping fimnel and a mechanical stirrer, was placed with a mixture of 275 ml. (4.3moles) of concentrated nitric acid and 275 ml. (4.9 moles) of concentrated sulfuric acid. This was cooled to I0°C in a freezing mixture, and 100 g. (0.85 moles) of benzylcyanide (free from alcohol and water) was run in slowly, at such a rate that the temperature remains at about 10°C and did not exceed 20°C. After all the benzyl cyanide has been added (about one hour), the ice bath was removed, and the mixture was stirred for one hour and then poured onto 1200 g. of crushed ice. A pasty mass slowly separated; more than half of this mass was p-nitrobenzylcyanide, the other constituents being o-nitrobenzylcyanide, and a variable amount of an oil which resists hydrolysis; apparently no di-nitro compounds were formed. The mass was filtered on a porcelain funnel with suction, pressed well to remove as much oil as possible & recrystalized from 500 ml boiling 95% alcohol,
p-Nitrophenyl acetic acid: In a round-bottom flask was placed 81 g. (0.5moles) of p-nitrobenzylcyanide. A solution of 242 ml. (4.35 moles) of concentrated sulfuric acid in 226 ml. of water was prepared, and two-third of this solution was poured onto the p-nitrobenzylcyanide. The mixture was shaken well, until the solid was all moistened with the acid. Any solid material adhering to the walls of the vessel was washed down into the liquid with the remainder of the acid; the flask was attached to a reflux condenser, then set for reflux without shaking and heated until the mixture boils. The boiling was continued for fifteen minutes. The reaction mixture,which becomes rather dark, was diluted with an equal volume of cold water and cooled to 0°C or below. The solution was filtered; the precipitate was washed several times with ice water and then dissolved in 1600 ml. of boiling water. This solution is filtered as rapidly as possible in hot condition & recrystalized from boiling water.
Azobenzene-4,4'-diacetic acid: Similar procedure of cross linker I was applied for II cross linker using 4-nitrophenyl acetic acid as starting material instead of 4-nitrobenzoic acid. Fourteen grams of 4-nitrophenyl acetic acid (79mmol) was heated in a solution of 50g of sodium hydroxide in 250 ml of water at 50°C. A solution of lOOg of glucose in 150 ml of water was added slowly at this temperature with occasional shaking. The reaction mixture was then cooled to ambient temperature and aerated for 8 hr with vigorous stirring until orange-colored crystals were formed. The mixture was acidified with dilute acetic acid; then the liberated diacid was filtered, washed with water and dissolved in hot potassium carbonate solution to get an orange-colored solution. This solution was

concentrated to get orange-colored crystals of potassium salt of diacid. On acidifying with dilute acetic acid, rose-colored Azobenzene-4, 4' -diacetic acid was obtained.
Azobenzene-4,4'-diaceticacid allyl ester: The synthesized Azobenzene-4,4'-diacetic acid (3gm) is refluxed with excess of thionyl chloride for 10 hrs. The excess of thionyl chloride was distilled off to get azobenzene-4,4'-diacetic acid-chloride. Also sodium salt of allyl alcohol was separately synthesized by reacting 1 mole of allyl alcohol with 2 moles of sodium metal. Then azobenzene-4,4'-diacetic acid chloride was dissolved in 1,4-dioxane and refluxed with sodium salt of allyl alcohol for 3-4 hrs. Finally the 1,4-dioxane layer was decanted & precipitate is filtered to take filtrate & concentrated to get solid product. Progress of reaction was monitored by using precoated TLC plates and structure was confirmed with IR spectroscopy.
[B] Synthesis of polymers: Acrylic acid networks crosslinked with Azobenzene-4,4'-diacid allyl ester were prepared using a bulk polymerisation technique. The inhibitor (hydroquinone monomethyl ether) was removed from the acid monomers by distillation process at following temperatures. After distillation nitrogen gas was bubbled in the container sealed properly and used within 24 h. benzoyl peroxide was used as the initiator.
Table No. 1: Temperature of monomer distillation

MONOMERS TEMPERATURE EOR DISTILLATION (°C)
n-Methyl methacrylate n-Butyl methacrylate 100 145
Predetermined quantity of acrylic monomers and azobenzene-4,4'-dicarboxylic acid allyl ester (linker 1st) / azobenzene-4,4'-diacidallyl ester (linker II) were introduced in Quickfit test tubes containing 5 ml of dry 1,4-dioxane. The reaction vessels were sealed and placed in a thermostated water bath at 70 C. After 24 h the vessels were uncapped and the polymeric networks were retrieved in the form of rods. The materials were pulverised in boiling methanol for 12 hr in order to remove any residual monomer and/or initiator & washing was done. The washed samples were dried under reduced pressure at 70°C for 24 hr.

Table No. 2: Quantities of monomers, cross-linker I (Azobenzene-4,4'-diacid allyl ester), initiator taken for Polymer synthesis.

Monomer (Ml) Monomer (M2) Molar Ratio (w/w) Volume taken (gm) Cross linker 1st (gm) Polymer Code Initiat
or
(gm)


Ml M2

Methyl methacrylate Butyl methaGrylate 1:1 3 4.27 0.1454(2%) PMB 1:1:2: A 0.121

0.2181(3%) PMB1:1:3:A

0.2908 (4%) PMB 1:I:4:A

0.5816(8%) PMB 1:1:8: A

Table No. 3: Quantities of monomers, cross-linker 2nd (Azobenzene-4,4'-diacetic acid allyl ester), initiator taken for Polymer synthesis.

Mono mer (Ml) Vlonomer
(M2) Molar Ratio
(w/w) Volume taken (gm) Cross linker 2nd (gm) Polymer Code Initiat
or (gm)

Ml M2

Methyl methacrylate Butyl methacrylate 1:1 3 4.27 0.1454(2%) PMB 1:1:2:B 0.121

0.2181 (3%) PMB 1:1:3:B

0.2908 (4%) PMB 1:1:4:B

0.5816(8%) PMB 1:1:8:B

Azobenzene-4,4'-dicarboxylic acid: The synthesis of Azobenzene-4,4'-dicarboxylic acid was carried out and structure was confirmed with the help of IR spectroscopy and following parameters were studied.

Table 4: Characterization of Azobenzene-4,4'-dicarboxylic acid

Parameters Observation
Color Pink
Melting point Above 360oC
Sodium fusion test for nitrogen Positive (persian blue color)
% Practical yield 80%
Solubility Methanol; 1,4-dioxane
Table 5: Interpretation of FTIR spectrum of Azobenzene-4,4'-diearboxyl acid

Peak observed (cm-1) Interpretation Peak observed
(cm-1) Interpretation
3030 C-H stretching (aromatic) 1423 N=N stretching
3448 O-H stretching 1296 Aryl conjugated C-0 stretching
1689 C=0 stretching (aryl conju.) 1215 O-H bending
1604 C=C stretching (aromatic) 871 Disubst. Benzene
1581 C ===C skeletal vibration
Azobenzene-4,4'-diallyl ester: The synthesis of Azobenzene-4,4'-di allyl ester was carried out and structure was confirmed with the help of IR spectroscopy, MS-MS analysis & Proton-NMR analysis. Also following parameters were studied.
Table 6: Characterization of Azobenzene-4,4'-di allyl ester

Parameters Observation
Color Orange red
Melting point Above 360oC
Sodium fusion test for nitrogen Positive (persian blue color)
% Practical yield 60%
Solubility Methanol; 1,4-dioxane

Table 7: Interpretation of FTIR spectrum Azobenzene-4,4'-diaIlyl ester

Peak observed
(cm"1) Interpretation Peak
observed
(cm"1) Interpretation
3124 Aromatic C-H stretching 1506 C===C skeletal vibration
2952 C-H stretching 1454 N=N stretching
1724 Aryl conjugated vinyl ester C=0 stretching 1365 C-N stretching
1604 C=C stretching (aromatic) 1288 Aryl conjugated C-0 stretching
2846 Aliphatic C-H str.(-CH2-) 1257 C-0 str. Acetates
1049 Aliphatic C-H bending(-CH2-) 995 Aliphatic C-H bending (-CH-)
875 Di substituted Benzene (aromatic)
Table 8: PMR Interpretation for Azobenzene-4,4'-diacid allyl ester.

Sr. No. δ ppm Splitting Assignments
1 3.49-3-74 Multiplate, 2*2H -CH2(a,a')
2 4.86-4.87 Double dublet 2 *1H -CH (b, b')
3 5.31-5.34 Multiplate, 1H =CH2 (He)
4 5.424-5.427 Double dublet 1H =CH2(Hcl)
5 5.46-5.47 Double dublet 1H =CH2(Hc2)
6 6.03-6.10 Multiplate, 1H =CH2(Hc3)
7 7.98-8.02 Multiplate, 4H Ar-CH (d)
8 8.21-8.27 Multiplate, 4H Ar-CH(d')


Table 9: Fragmentation pattern for Azobenzene-4,4'-diallyl ester.
Synthesis of 2nd Cross-linking agent (Azobenzene-4,4'-di acetic acid allyl ester):
p-Nitrobenzylcyanide: The synthesis of p-Nitrobenzylcyanide was carried out and structure was confirmed with the help of IR spectroscopy and following parameters were studied.
Table 10: Characterization of p-Nitrobenzylcyanide

Parameters Observation
Color Yellow prisms (crystals)
Melting point 116oC
Dye test for nitro group Positive (orange colored dye)
Sodium fusion test for nitrogen Positive (persian blue color)
% Practical yield 85%
Solubility Methanol, Ethanol, Ether

Table 11: Interpretation of FTIR spectrum p-Nitrobenzylcyanide

Peak observed
(cm"1) Interpretation Peak observed
(cm'1) Interpretation
3024 Aromatic C-H stretching 1523,1350 Aromatic C-N02 stretching
2943 Aliphatic C-H stretching 1415 -CH2 (in plane) Deformation
2254 Aryl conjugated C==N stretching 1217 C-N stretching
1712 -CH2 Deformation (overtone) 812 Para Disubsituted benzene ring
1602 Aromatic C=C skeletal vibration
p-Nitrophenyl acetic acid: The synthesis of p-Nitrophenyl acetic acid was carried out and structure was confirmed with the help of IR spectroscopy and following parameters were studied.
Table 12: Characterization of p-Nitrophenyl acetic acid

Parameters Observation
Color Pale yellow long needles (crystals)
Melting point 153oC
Dye test for nitro group Positive (orange colored dye)
Sodium fusion test for nitrogen Positive (persian blue color)
% Practical yield 90%
Solubility Methanol, Ether, Benzene, Ethanol

Table 13: Interpretation of FTIR spectrum p-Nitrophenyl acetic acid

Peak observed
(cm1) Interpretation Peak
observed (cm1) Interpretation
3085 Aromatic C-H stretching 1521,1346 Aromatic C-NO2 stretching
2927 Aliphatic C-H stretching 1307 O-H bending
1710 Aryl conjugated C=0 str. 1323 C-N stretching
1602 Aromatic C-C skeletal vibration 817 Para disubsti. benzene ring
2848 Bonded O-H stretching (broad) 1199 Aromatic C-0 stretching
Azobenzene-4,4'-di acetic acid: The synthesis of Azoben2ene-4,4'-diacetic acid was carried out and structure was confirmed with the help of IR spectroscopy and following parameters were studied.
Table 14: Characterization of azobenzene-4,4'-diacetic acid

Parameters Observation
Color Dark Red
Melting point Above 360oC
Sodium fusion test for nitrogen Positive (persian blue color)
% Practical yield 60%
Solubility Methanol; 1,4-dioxane
Table 15: Interpretation of FTIR spectrum of Azobenzene-4,4'-diacetic acid

Peak observed (cm-1) Interpretation Peak observed (cm"1) Interpretation
3056 Aromatic C-H stretching 1450 N=N stretching
3367 O-H stretching 1255 O-H bending
1680 Aromatic C~0 stretching 1290 Aryl conjugated C-0 stretching
2916 Aliphatic C-H stretching 1521 C C skeletal vib.
1652 C=C stretching (aromatic) 1389 C-N stretching
858 Para disubstituted benzene.
Azobenzene-4,4'-diaceticallyl ester: The synthesis of azobenzene-4,4'-diacetic allyl ester was carried out and structure was confirmed with the help of IR spectroscopy and NMR analysis. Also following parameters were studied.

Table 16: Characterization of Azobenzene-4,4'-diacetic allyl ester

Parameters Observation
Color Brown red
Melting point Above 360UC
Sodium fusion test for nitrogen Positive (persian blue color)
% Practical yield 60%
Solubility Methanol; 1,4-dioxane
Table 17: Interpretation of FTIR spectrum Azobenzene-4,4'-diacid allyl ester

Peak observed Interpretation Peak observed Interpretation
(cm1) (cm"1)
3045 Aromatic C-H stretching 1508 Aromatic C C
deformation
2966,2918 Aliphatic C-H stretching 1444 N=N stretching
1724 Aryl conju. C=0 stretching (vinyl ester) 1369 C-N stretching
1649 C=C stretching 1290,1255 Aryl conjugated C-0 stretching (acetates)
1063 Ali. C-H bend. (-CH2-) 1017 Ali. C-H bend. (-CH-)
Table 18: PMR Interpretation for Azobenzene-4,4,-diacetic allyl ester.

Sr. No. δppm Splitting Assignments
1 0.80-0.83 Multiplate, 1H -CH2 (Ha)
2 1.21-1.24 Singlet, 2*1H -CH2(Hal, Ha2)
3 3.33-3.426 Singlet, 2*5H =CH2(b,bVCH(c,c'), -CH2(d,d')
4 6.56-6.58 Multiplate, 1H -CH2(Ha3)
5 7.26-7.67 Multiplate, 2*4H Ar-CH (e, e')

Table 19: Appearance and Percentage Practical yield of polymers

Polymer code Appearance % Practical yield
PMB1:1:2:A Whitish Orange crystalline powder 82.30
PMB1:1:3:A Yellowish Orange crystalline powder 78.80
PMB1:1:4:A Faint orange red crystalline powder 79.20
PMB1:1:8:A Dark Orange red crystalline powder 83.30
PMB1:1:2:B Whitish orange sticky opaque crystals 26.80
PMB1;1:3;B Yellowish orange sticky opaque crystals 32.90
PMB1:1:4:B Orange sticky opaque crystals 35.80
PMB1:1:8:B Dark red orange sticky opaque crystals 28.20
Film forming property studies;
Table 20: Film forming properties

Polymer code Ethanol (Solvent) with Dibutyl phthalate (plastisizer %w/v)

3 (%w/v) 4 (%w/v) 5 (%w/v)
PMB 1:1:2:A + ++ ++
PMB 1:1:3: A - + ++
PMBI:1:4:A - + ++
PMB 1:1:8:A - + ++
PMB 1:1:2:B + ++ ++
PMB 1:1:3:B - + ++
PMB1:1:4:B - + ++
PMB 1:1:8:B - + ++

- .'negligible film formation, +.non-continuous film formation, ++:continuous film formation.
Solubility study:
Table 21: Solubility study of polymers in various solvents

Polymer Code Solubility

S1 s2 S3 s4 s5 s6 s7 s8 s9 S10 S11
PMB1:1:2:A + ++ ++ + + ++ + ++ + * ++
PMB 1:1:3:A 4- ++ ++- + + ++ + ++ + ++ *
PMB1:1:4:A + ++ ++ + + ++ + ++ + * *
PMB1:1:8:A + ++- ++ + + ++ * ++ 4- ++ ++
PMB1:1:2:B + ++ ++ + + ++- + ++ + ++ ++
PMB1:1:3:B + ++ ++ + + ++ + ++ + ++ *
PMB1:1:4:B - + + + + + + ++ + ++ *
PMB1:1:8:B - + + + + + * + + * *
S1: Acetone, S2: ethanol, S3: Methanol, S4: Ethyl acetate, S5: Methylene dichloride, S6: Methylene dichloride: Ethanol (50:50), S7: Toluene, S8: Dioxane, S9: Chloroform, S10: Dimethyl sulfoxide, S11- Dimethyl formamide; - .insoluble, +:partially soluble, ++ completely soluble, * dwelling.

Bio-degradation Studies of polymers: Table 22: Biodegradation study of polymers

Polymer Code Polymer Degradation

pH 6.8 Buffer (Control) pH 6.8 Buffer + Rat caecal content (-ve Control) pH 6.8 Buffer + Rat caecal content+ anaerobic conditions
PMB1:1:2:A 0 0 ****
PMB 1:1:3:A 0 0 ****
PMB1:1:4:A 0 0 ***
PMBI:1:8:A 0 0 **
PMB 1:1:2:B 0 0 ****
PMB 1:I:3:B 0 0 ****
PMB1:1:4:B 0 0 ***
PMB1:1;8:B 0 0 **
0:No pore formation, **:partial pore formation, ***:complete pore formation, ****:Complete film
degradation
Table 23: Interpretation of FTIR spectrum of polymers

Peak observed (cm1) Interpretation Peak observed
(cm-1) Interpretation
3700-2500 O-H Intermolecular 1739 C=0 strech ester
3400-2400 O-H stretching 1710 C=0 strech acid
3020 Ar C-H stretching 1508 Ar C=C stretching
2966 C-H stretching 1433 N=N stretching
1724 C=0 stretching 1323 C-N stretching
1604 C=C stretching 1288 C-0 stretching

Table 24: Comparison of results of identification tests of drug sample with the reported stds.

Identification Test Observed Result Reported Standard
Appearance Crystalline powder Crystalline powder
Colour White White
Odour Odourless Odourless
Melting point 231-234°C 231-233° C
Table 25: Maximum wavelength of absorption (X max) of Budesonide in different media

Solvents λ max (nm)
pH 1.2 acid buffer + 1% v/v Tween 20 247.00
pH 6.$ phosphate buffer + 1% v/v Tween 20 247.00
6.8 phosphate buffer + Rat caecal content + 1% v/v Tween 20 244.00
Table 26: Interpretation of FTIR spectrum of drug

Peak
observed
(cm-1) Interpretation Peak observed
(cm-1) Interpretation
2869 C-H stretching (aliphatic) 1600 C=C stretching (aro.)
2954 C-H stretching (aromatic) 1292 C-0 stretching (aro.)
3494 O-H stretching 1049 C-O stretching
1720 C=0 stretching 1396,1438 C-H bending
1353 O-H bending 1623 C=C, C=0 conjugated
Solubility study:
Table 27: Solubility of budesonide in different media

Solvent Solubility (mg/ml)
Water Insoluble
pH 6.8 phosphate Buffer +Tween 20 (1%) 0.30

Table 28: Evaluation of Capsules

* Each sample was analyzed in triplicate (n=3) Table 29: Disintegration study

Parameter Polymer uncoated Polymer coated
budesonide capsules budesonide capsules
Outer Diameter* (mm) 6.35 (±0.066) 6.75 (±0.0471)
Height of capped 18.05 (±0.136) 18.47 (±0.0384)
capsule* (mm)

Tablet Disintegration Fluid Criteria as per IP Results
Coated Hydrochloric acid No evidence of No evidence of
capsules* buffer pH 1.2 disintegration (2 hr) disintegration (2 hrs)

Phosphate Buffer pH No evidence of No evidence of
6.8 disintegration (60 min) Disintegration (60 min)
Uncoated Hydrochloric acid All tablets should All tablets disintegrated in
capsules* buffer pH 1.2 disintegrate in Less than 5 min. 2.10±0.102(min)
* Each sample was analyzed in triplicate (n=3)

Table 30: Drug release study of polymer coated capsules.

Time (Hrs) Medium PMB1:1:2:A coated capsules (n=3) (In %) PMBsl:l:2:B coated capsules(n=3) (In %)
2 pH 1.2 acid buffer +1 % Tween 20 0 0
5 pH 6.8 phosphate buffer +1 % Tween 20 6.76±1.63 5.68±0.14
6 pH 6.8 phosphate buffer + 1 % Tween 20 + rat caecal content 32.44±0.28 22.36±0.57
7
44.55±0.63 25.99±1.46
8
50.59±0.94 30.51±1.65
9
56.77±1.59 37.42±0.38
10
57.86±0.92 45.51±0.71
11
61.45±0.04 47.41±0.34
12
62.99±0.93 50.73d=1.06
13
63.87±0.37 S5.09±1.00
14
70.98±1.17 56.97±0.18
15
74.87±0.77
59.08±0.83
16
79.89±0.84 63.51±2.23
17
85.77±1.06 68.03±1.22
18
91.56±1.48 72.78±1.43
19
97.75±1.63 78.74±1.20
20
82.44±0.01
21
93.69±0.91
22
98.99±1.47

Table 31: Comparison of Drug release of first 5 hours (media with & without Rat caecal content)

Time (Hrs) PMB1:1:2:A PMBs l:l:2:B coated
Medium coated capsules capsules
(n=3) (In %) (n=3) (In %)
Capsules were placed simultaneously in pH 1.2 acid buffer +1 % Tween 20 medium for 2 hrs &
then replaced with following media
5 pH 6.8 phosphate buffer +1 % Tween 20 6.76±1.63 5.68±0.14
5 pH 6.8 phosphate buffer + 1 % Tween 20 + Rat Caecal Content 36.98 25.03
Drug release kinetics: The release data obtained were fitted to Zero order, First order, Higuchi and Korsmayer-Peppas equations to determine the corresponding release rate and mechanism of drug release. Table 32: Corelation coefficient values for various kinetic models.

Capsules coated with Zero order First order Higuchi Korsmeyers peppas

R R R R N
PMB1:1:2:A 0.943600691 0.784629379 0.8931117 0.907862605 1.72207
PMB 1:1:2:B 0.980060788 0.652637712 0.879999368 0.939860856 1.63671

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5. We claim:
1) We claim that Diazo group undergoes enzymatic reduction and cleavage to free NH2 by azoreductase enzyme
2) We claim that Methyl methacrylate as a biodegradable diazo cross-linking agent for all types of vinyl polymer and cross polymer.
3) We claim that Butyl methacrylate as a biodegradable diazo cross-linking agent for all types of vinyl polymer and cross polymer.
4) We claim that The process of manufacturing azobenzene-4,4'-