INTRODUCTION:

Now days the colon has recently become accepted as an increasingly important site for drug delivery. Colon specific diseases are often inefficiently managed by oral therapy, colon specific drug delivery systems, which can deliver drugs to the lower gastrointestinal tract without releasing them in the upper GI-tract, can be expected to increase the quality of life for patients suffering from colon specific diseases. Treatment might be more effective if the drug substances were targeted directly on the site of action in the colon.^1-3 The concentration of drug reaching the colon depends on formulation factors, the extent of retrograde spreading and the retention time.

Number of serious diseases of the colon might be capable of being treated more effectively if drugs were targeted on the colon.^4-6

Colon drug delivery is a relatively recent approach to the treatment of diseases and irritable bowel syndrome, recommended treatments include the administration of anti-inflammatory drugs, chemotherapy and antibiotics, which must be released in colon.⁷ Such local treatment has the advantages of requiring small drug quantities, possibly leading to reduce the incidence of side effects and drug interactions.^8-10 The usual treatment of anti-inflammatory bowel disease consists of frequent intake of anti-inflammatory drugs at high doses in order to induce remission of active diseases leads to side effects like dizziness, GI disturbances, headache and skin rash.^11,12 The pH dependent approach for colonic drug delivery is based on the pH differential along the gastrointestinal tract with values increasing from about 1 to 2.5 in the stomach through 6.6 in the proximal small bowel to a peak of about 7.5 in the terminal ileum followed by a fall in pH to 6.4 in the colon.^13,14 This concept utilizes polymeric carriers that are insoluble in the low pH media of the upper gastrointestinal tract, but dissolve at the higher, near neutral pH of the distal gut.^15,16.

Drug delivery to the colon is beneficial for many drug molecules, especially for those drugs that are used to treat ulcerative colitis, diarrhea and colon cancer. NSAIDs cause side effects such as indigestion, stomach ulcers, headache, dizziness, etc. 5-ASA is a commonly used NSAID belonging to BCS Class IV. Also daily required dose ranges from 2.4-4.8g/day.

To overcome these side effects, there was need to design a suitable drug delivery system with minimum dose that targets 5-ASA to colon releasing it after a predetermined lag time. This will not only increase effectiveness, so the therapy will help to reduce dose, dosing frequency, side effects along with improved patient compliance.^17-20

Various polysaccharides have been explored for controlled drug delivery system. Fenugreek gum is easily available, biodegradable, biocompatible and shows solubility in alkaline pH thus drug release can be achieved in colon itself. Hence, abundantly available fenugreek gum has been investigated as an enteric coating polymer for designing of a targeted drug delivery to colon. The amino acid group present in the chitosan carries positive charge, where as in case of fenugreek gum, it carries a negative charge due to presence of coo^-group. The formation of complexes between these two polymers employed protecting drug release in the stomach and allows it to release drug into colon.

The present investigation was to prepare enteric coating tablet and investigate it’s characteristics and study of prolong the release of the anti-inflammatory drug 5-ASA to the colon using one such pH dependent polymeric systems, this new system will stay intact and enable the drug to be delivered in a delayed manner in order to provide effective treatment for IBS.

MATERIALS AND METHODS:

5- amino salicylic acid was obtained as a gift sample from Cipla Pvt. Ltd., Mumbai, India. Chitosan was purchased from Molychem, Mumbai, India. Polyvinyl pyrolidone was purchased from Loba chemie Pvt. Ltd. Mumbai. Micro crystalline cellulose was purchased from Evonik India Pvt. Ltd., Mumbai, India. All other solvents and reagents in this work were of analytical/HPLC grade and used as provided.

Preformulation studies:

The 5-ASA drug was evaluated for their colour, odour, taste, state etc. Melting point of pure drug was determined by open capillary tube method. Solubility of 5-ASA was carried out by gravimetric method.

Extraction, purification and characterization of fenugreek gum:

Fenugreek gum was prepared from dry seeds of fenugreek according to the method.²³The seeds (125g) were ground to fine powder (300 mesh) and extracted by the soxhlet procedure in the presence of 200ml n-hexane for 5h. The solid fraction was further extracted with ethanol (200ml) followed by methanol (150ml). The extract was vacuum evaporated.

The remaining solids were further treated and dissolved in water (800-1000ml) to form a viscous aqueous solution of crude fenugreek gums and centrifugation at 1000rpm and 2500rpm. The water soluble fractions were combined and the hydrocolloid fractions were precipitated by adding ethanol (1:1, w/w). The precipitated gum was dried in desiccators for complete removal of water.

Characterization of fenugreek gum:

Determination of the Percentage yield of fenugreek gum:

The percent yield of the fenugreek gum was calculated from

Practical yield

% yield = ---------------------- ×100…………….1

Theoretical yield

Preliminary chemical tests:

Fenugreek gum was subjected for preliminary tests like, identification of presence of different carbohydrates. Morphological properties of gum was evaluated for their colour, odour, taste, state etc. Solubility of Fenugreek gum was carried out by gravimetric method in which 1gm of fenugreek gum was dispersed in different solvent like water, ethanol, acetone, chloroform, methanol, 0.1N HCL, Lithium bromide solution, calcium chloride and magnesium chloride solutions.

Swelling index:

The study was carried out using a 100 ml stoppered graduated cylinder. The initial bulk volume of 1gm of fenugreek gum was noted. Water was added in sufficient quantity to produce 100 ml of a uniform dispersion. The dispersion was stored at room temperature and the sediment volume of the swollen mass was measured after 24 h.

(V2-V1)

Swelling index = ----------------- ×10……………2

Where: V1 = Initial volume of material before hydration. V2 = Volume of hydrated material

Table 1: Preparation of core tablets

Ingredients	BATCHES ( weight in mg)
Ingredients	F1	F2	F3	F4	F5	F6	F7	F8	F9
Drug	150	150	150	150	150	150	150	150	150
Microcrystalline cellulose	40	36	37	35	43	44	42	44	42
Lactose	38	44	43	45	37	36	38	36	38
Poly vinyl pyrrolidone	12.5	11.5	10.5	9.5	8.5	7.5	6.5	5.5	4.5
Isopropyl alcohol	qs	Qs	qs	qs	Qs	qs	qs	qs	qs
Sodium starch glycolate	7	8	9	10	11	12	13	14	15
Isopropyl alcohol	qs	Qs	qs	qs	Qs	qs	qs	qs	qs
Magnesium stearate	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
	250	250	250	250	250	250	250	250	250

Micromeritic properties and solid state analysis of fenugreek gum was evaluated for bulk density, tapped density, carr’s index, hausner’s ratio, angle of repose etc. ATR-FTIR analysis, differential scanning calorimeteric analysis and powder x-ray diffraction analysis of fenugreek gum.

Preparation and characterization of granules:

Core tablets of 5-ASA were prepared by wet granulation technique using PVP as a binder. Lactose and microcrystalline cellulose (MCC) were used as diluents and sodium starch glycolate as a super disintegrant was granulated by passing through #10 mesh and prior to granulation by passing all the materials were passed through #10 mesh. The dried granules were passed through #20 mesh and these granules were lubricated with magnesium stearate. Finally granules were compressed into tablets by using rotary tablet press.

The angle of repose for blend of each formulation was determined by the funnel method. The blend was allowed to flow through the funnel orifice on a plane paper kept on horizontal surface. This forms a pile of angle of blend on the paper. The angle of repose was calculated by substituting the values of the base radius ‘r’ and pile height ‘h’ in the equation 3.

tan ϴ = ----- …………………………………3

Bulk density is the ratio of mass and bulk volume. 20 gm powder blend was allowed to flow in a fine stream into a graduated measuring cylinder and final volume was noted. The bulk density was obtained by dividing the weight of the sample in grams by final volume in cm³and it was determined by formula 4.

Bulk mass

Bulk density = -------------------……………...4

Bulk vloume

Tapped density was determined, 20 gm blend was allowed to flow in a fine stream into a graduated cylinder of a mechanical tapping device. The measuring cylinder was tapped for 100 times and final tapped volume was noted. The tapped density was obtained by dividing the weight of the sample in grams by final tapped volume in cm3 and it was calculated by using formula 5.

Bulk mass

Tapped density = ----------------------………...5

Tapped vloume

Carr’s index was determined the percentage compressibility of a powder was a direct measure of the potential powder arch or bridge strength and stability. Carr’s index of each formulation was calculated by using formula 6. The grading of blend according to Carr’s index was shown in table 2. Hausner’s ratio, is essential to determine the compressibility strength of powders and it was determined by using formula 7.

Tapped density – Bulk density

Carr’s index = -------------------------------------- × 100…6

Tapped density

Hausner’s ratio = ------------------------- ………7

Bulk density

Preparation and evaluation of inner core tablets:

The formulated inner core tablets were evaluated for different parameter like thickness, diameter, hardness, uniformity of weight and in-vitro dissolution studies. Thickness and diameter were measured using vernier caliper. The hardness of tablet of each formulation was measured by Monsanto hardness tester. Friability of tablets was measured by Roche friabilator. In brief ten tablets were weighed accurately and placed in the drum that revolves at 25 rpm dropping the tablets through a distance of six inches with each revolution. After 4 min the tablets were weighed and the percentage loss in tablet weight was determined by using formula 8. In vitro disintegration time of six tablets from each formulation was determine by using disintegration test apparatus (VEEGO). In vitro disintegration test was carried out at 37 ± 0.5ºC in 900 ml of distilled water.

Initial wt of tablet – Final wt of tablet

% Friability = ------------------------------------ × 100 …………..8

Intial wt of tablet

Coating of core tablets:

Preparation and characterization of enteric coating solution:

The enteric coating solution was prepared by dissolving fenugreek gum and chitosan in to water and 1% glacial acetic acid. The core tablets were coated with the concentration of 2%, 5%, and 7% in the ratio of 50:50, 40:60, 60:40, 70:30 and 30:70 of fenugreek gum and chitosan. Coating of core tablets was performed using a pan coating machine. In brief, tablets were charged in coating pan for 30 minutes. Spray air pressure is 3kg/cm², temperature 35-50ºC, rotating speed of pan 20rpm. The amount of coating was up to 30mg (4%w/w) per tablet. Various evaluation parameters of prepared coated tablets such as thickness, diameter, hardness, friability and in vitro disintegration were determined.

In vitro dissolution study:

In vitro drug release study was conducted by using USP type II apparatus. The dissolution media (900ml) comprised of buffer pH1.2 for first 2h then phosphate buffer (pH 6.8) for 10h kept at 37±0.5ºC and rotation 100rpm. The contents of 5-ASA were determined by measuring absorbance by using UV-Visible Spectrophotometer. An aliquot of 5ml sample was withdrawn and replaced with same of fresh dissolution medium at various time intervals, dissolution was continued in phosphate buffer pH6.8 till end of the test, absorbances were recorded.

ATR-FTIR Analysis:

ATR-FTIR spectra of optimized batch was recorded using Infrared spectrophotometer (Jasco-V-530 model). About 2mg of sample was ground thoroughly with KBr; uniformly mixed sample kept in sample holder and spectra were recorded over the wave number 400-4000cm^-1. The procedure consisted of dispersing sample in excess of potassium bromide nearly at the ratio 1:100, mixed well and mixture kept in to sample holder for analysis. FT-IR spectra of the optimized batches were taken to study drug-polymer interaction.

Differential Scanning Calorimetry:

Differential scanning calorimetry (DSC) studies were carried out using Mettle-Toledo DSC821 instrument. Indium and zinc standards were used to calibrate the DSC temperature and enthalpy scale. The optimized batch of coated 5-ASA are hermetically sealed in aluminum crucible and heated at a constant rate of 10°C/min over a temperature range of 25-400°C. Inert atmosphere was maintained by purging nitrogen gas at flow rate of 50ml/min, respectively.

X-Ray Diffraction Studies:

The XRD patterns were recorded on X-ray diffractometer (PW1729, Philips. Netherlands). Samples were irradiated with monochromatized Cu-K a radiation (1.542 A˚) and analyzed from 50 to 500 2θ. The voltage and current used were 30kV and 30mA, respectively. The X-ray diffraction procedure to estimate the degree of crystallinity was based upon the measurement of the total scattering and the scattering from the crystalline region of formulations.

Stability studies:

Stability studies of the potential enteric coating formulation was performed at accelerated condition (40°C±2°C, 75%±5% RH) conditions as per ICH guidelines. Samples were withdrawn at 1, 2 and 3 month from the time of placing sample into the chamber. The thickness, diameter, hardness, friability, disintegration and % drug release were analyzed.

RESULTS AND DISCUSSION:

Preformulation studies:

The sample of 5-ASA was found to be tan to light pink crystalline powder with characteristic odour. The melting point of 5-ASA was in the range of 286-289°C. ATR-FTIR Analysis of 5-ASA, peaks were found to be similar to the peaks that represent the basic aromatic ring, carboxylic group and amino groups.

Fig.1: ATR-FTIR spectra of 5-ASA (A) and pure Fenugreek gum (B)Extraction, purification and characterization of fenugreek gum:

ATR-FTIR spectra of 5-ASA shown in figure 1(A), characteristic peaks at 1621.24, 2976.52, 1487.79, 1355, 1194.90 cm_-1. DSC thermogram of pure 5-ASA showed a sharp endothermic peak at 289.14°C. From the thermogram it was clear that 5-ASA was crystalline in nature. PXRD spectra of 5-ASA shows characteristic peaks at11.29, 17.71, 21.78, 23.56, 32.25, 36.38, and 39.24 2θ values. PXRD spectra showed sharp and intense diffraction peaks, which were an indication that 5-ASA can be considered as crystalline in nature.

Characterization of fenugreek gum:

Molisch’s test, Benedict’s tests were positive test. Melting point of fenugreek gum as determined by capillary method was found to be in the range of 299-302°C. Physicochemical characterization of Fenugreek gum were light yellowish brown, odourless, tasteless, amorphous powder, pH 6.8, loss on drying 11%, swelling index 74.15%, slightly soluble in cold water, but moderately dissolves in warm water, forms viscous solution, insoluble in organic solvents, yield 18% and viscosity (1%) 293.94 cps. Micromeritic properties of gum was bulk density 0.396g/cm3, tapped density 0.413 g/cm3, compressibility index 14.11%, hausner’s ratio 1.042 and angle of repose 22.4°.

Attenuated total reflectance -Fourier Transform Infrared Spectrophotometer Study (ATR-FTIR), Due to the presence of OH groups in fenugreek gum, the characteristic chelate formation around 3279.13cm_-1 were assigned to the absorption peak, bands around 1631.38cm_-1(C=O stretching), to the bands around 2924.23 (C-H stretching), and cyclic quinines around 1529.74 cm_-1. All these characteristic absorbance peaks indicate the existence of glycosidic bond. The molecular conformation of fenugreek gum was characterized by β-sheet absorption peaks around 3279.13, 2924.23, 1631.38 and 1529.74 cm_−1, random coil conformation absorption peaks at 3288, 2901, 1654 and 1262 cm₋₁. The FTIR spectra fenugreek gum was shown in figure 1(B). The DSC thermogram of Fenugreek gum showed broad endothermic peak at 302.32°C indicating that it was amorphous in nature. PXRD study of Fenugreek gum powder found a diffraction peak near 2θ=22°, and shoulder peak at near 2θ=13.16°, 18.14_o, 20.52° and 22.46°. Intensities of these peaks were very short so, it can be considered that less crystalline or can be said to be amorphous in nature.

Preparation of core tablets:

1. Characterization of granules:

The granules were prepared by wet granulation methods. The optimum concentrations of binder (PVP) required for the granules to be free flowing. The concentration of binder in the granules is around 4% according to IP. The results of core tablets shown in table 2. The prepared mass was pass through the sieve no 10. These granules were dried in oven at 60⁰C for 1 h. The dried granules were further passed through sieve no 20. In collected granules 5% fines were added and characterization by various parameters.

From the results of 9 batches, the F-9 batch shows values for all parameters within standard range. The optimum range for Carr’s index and angle of repose was around 5-15% and 25° respectively. The F-9 batch shows Carr’s index and angle of repose was around 10% and 24° respectively, indicating that F-9 batch having excellent flow property. The Hausner’s ratio of F-9 batch was 1.14. This indicates lesser the Hausner’s ratio better would be the flow property. The other batches shows bulk density, tapped density, Carr’s index, friability and angle of repose were found to be in the range 0.444 to 0.384, 0.545 to 0.574, 15 to 18, 1.23 to 1.36. and 25 to 30° respectively.

Characterization of core tablets:

The core tablets were evaluated for several properties. The concentrations of binder (PVP) and super disintegrant (sodium starch glycolate) were varies in all batches. The optimized batch F-9 was selected because; it shows values for all parameters within a standard range. The optimum concentration of PVP and sodium starch glycolate was 4.5mg and 15mg respectively, which shows disintegration, time 2min. The core tablets of F-9 batch shows weight variation, hardness, friability were 1.20±0.004, 5.1±0.10kg/cm² and 0.94±0.005%, which follows standard parameters according to IP. The other batches shows the weight variation, hardness, thickness, friability and disintegration time were 1.20 to 2.20, 4.5 to 5.5kg/cm², 4.6 to 5.3mm, 0.95 to 1.95 and 5 to 15min. Various parameters for tablet properties shown in table 3.

Table 2: Characterization of granules

Bathes	Bulk density	Tapped density	Carr’s index	Hausner’s ratio	Angle of repose
F1	0.384±.002	0.574±0.08	18.14±0.09	1.36±0.141	29.14±0.02
F2	0.414±0.045	0.566±0.09	17.22±0.06	1.11±0.237	27.50±0.04
F3	0.401±0.057	0.597±0.03	19.65±0.08	1.24±0.217	26.20±0.04
F4	0.411±0.006	0.588±0.06	20.59±0.06	1.50±0.169	20.10±0.06
F5	0.416±0.035	0.579±0.05	16.77±0.04	1.64±0.142	22.40±0.05
F6	0.423±0.045	0.557±0.07	17.94±0.02	1.44±0.045	29.50±0.04
F7	0.456±0.067	0.597±0.06	19.47±0.03	1.65±0.067	23.59±0.06
F8	0.444±0.079	0.551±0.07	12.17±0.07	1.54±0.078	25.58±0.097
F9	0.425±0.099	0.555±0.08	10.00±0.054	1.14±0.097	24.00±0.099

* Indicates average readings± SD (n=3)

Table 3: Characterization of tablet

Batches	Weight variation	Hardness	Thickness	Friability	Disintegration Time in min
F1	1.65±0.02	4.9±0.12	5.1±0.17	0.52±0.026	13
F2	1.93±0.20	5.1±0.18	5.2±0.29	0.67±0.012	11
F3	2.22±0.05	5.3±0.24	5.1±0.25	1.34±0.014	10
F4	1.67±0.10	4.8±0.20	5.0±0.19	1.56±0.021	9
F5	2.24±0.09	4.9±0.16	5.1±0.14	2.34±0.009	8
F6	2.06±0.06	5.1±0.37	5.1±0.04	1.10±0.015	6
F7	1.24±0.02	4.5±0.11	4.6±0.09	1.65±0.024	5
F8	1.12±0.015	4.9±0.09	5.1±0.10	1.95±0.015	3
F9	1.20±0.004	5.1±0.10	5.1±0.13	0.94±0.005	2

* Indicates average readings± SD (n=3)

Table 4: Characterization of coated tablet

Batches	Weight variation	Hardness	Thickness	Friability	Disintegration Time in min
F1	1.60±0.002	4.7±0.12	5.1±0.17	0.52±0.026	8
F2	1.83±0.20	5.5±0.18	5.2±0.29	0.67±0.012	6
F3	2.35±0.05	5.1±0.24	5.1±0.25	1.34±0.014	5
F4	1.99±0.10	5.1±0.20	5.4±0.19	1.56±0.021	6
F5	2.20±0.09	4.6±0.16	5.3±0.14	2.34±0.009	7
F6	2.65±0.06	5.1±0.37	4.9±0.04	1.10±0.015	4
F7	1.24±0.02	4.9±0.11	4.6±0.09	1.65±0.024	8
F8	1.76±0.015	4.7±0.09	5.1±0.10	1.95±0.015	6
F9	1.60±0.004	5.3±0.10	5.3±0.13	0.90±0.005	4

* Indicates average readings± SD (n=3)

Coating of core tablets:

The coating of core tablets were conducted by using fenugreek gum, chitosan with different concentration and proportions such as 2%, 5%, 7% and 50:50, 60:40, 40:60, 70:30, 30:70 respectively. The coated tablet shows slight difference in the hardness, thickness and friability. The disintegration of coated tablets were increased. The disintegration of coated tablets was found to be 4 min. Characterization of coated tablet shown in table 4.

In vitro dissolution studies:

In vitro release studies was carried out at various conditions that simulate in vivo colonic transition of a formulation. 5-ASA release was studied in various dissolution medias that includes simulated gastric fluid (SGF) pH1.2 for 2h, simulated intestinal fluid (SIF) pH 7 for further 2h and finally in simulated colonic fluid (SCF) pH6.8 till 10h. From the coated 5-ASA tablets release profile of drug was shown at fenugreek gum: chitosan, 50:50 concentration of coating solutions in figure 2(A). The dissolution study was shows that the optimum concentration of coating solution 7%. There was only 28% of drug released within 5h, where as other batches show 50% drug releases in the 5h.

The release profile of drug with 5% concentration of coating solution gives about 45% drug release within 5 h, which was not suitable for colonic targeting. About 80% drug release occurs in 8 h. So there was a need to be increase in the concentration of coating solution. The release profile of drug was shown in figure 2(B). Release profile of drug with 7% concentration of coating solution of tablet. The tablets coated with 7% concentration of fenugreek gum and chitosan in the ratio 70:30 gives only 15.69% drug release within 5 h, where as other batches show around 30% drug release. About 89.99% drug release was achieved at 10 h. The optimum concentration of fenugreek gum and chitosan for coating of core tablet was 7% in the ratio 70:30, which was shown in figure 2(C). The graph of the optimised batch (F 70:30) shows the sigmoidal drug release. The formation of complexes between fenugreek gum and chitosan prevents the drug release in the stomach. The tablets coated with 7% concentration solutions in the ratio 70:30 shows better swelling property and 89.99% drug releases in the colon.

ATR-FTIR analysis of coated tablet:

The FTIR of coated tablet showed the interaction of polymers such as fenugreek gum and chitosan with pure drug. This study demonstrates the proper coating to the tablets has been achieved or not. The peak of the coated tablets shows nearly similar as that of pure drug and only there was change in the peaks of coated polymers. So there was no interaction takes place between drug (5-ASA) and polymer (fenugreek gum and chitosan) indicates the formation of amide linkage at 1569.52 cm^-1 and 1440.15cm^-1. FTIR spectra of coated tablet shown in figure 3(A). It was confirmed that the coating of fenugreek gum and chitosan was done successfully since its characteristic peaks could be differentiated from that of pure drug. FTIR shows that there was no any change in the peak of the drug indicating that no interaction with the drug and polymer. Overlain ATR-FTIR spectra of Fenugreek gum, 5-ASA and coated tablet shown in figure 3(B).

Fig. 2: % release profile of drug (A), 5% coating solution (B) and 7% coating solutions(C)

DSC of coated tablet:

DSC thermal profile of pure drug 5-ASA showed a sharp endothermic peak at 289.14°C attributed to melting of 5-ASA. If there was change in the melting point of the formulation indicates the interactions between the drug and polymers. The DSC thermal profile was determines the nature of drug either in amorphous or crystalline form. The change in the peak width indicates change in the crystallinity. The broader the peak indicates that drug was in amorphous form. The melting point of coated tablet was found to be 293.81°C which relates to pure drug which has melting point 289.14°C.

Fig.3: FTIR spectra of coated tablet and Overlain of ATR- FTIR spectra a) 5-ASA coated tablet

b) Physical mixture of polymers and drug c) Fenugreek gum d) Pure drug 5-ASA

Hence there was no interaction between drug and fenugreek gum and chitosan. The DSC of polymer coated tablet shown in figure 4(A). The DSC of physical mixture shows that there was no any change in the melting point of 5-ASA. Hence the polymers used for coating of tablets were compatible with each other. The melting point of mixture is found to be 285.89°C. The melting point of pure drug is 289.14°C, which was similar almost near to physical mixture indicating that there was no any interaction between fenugreek gum, chitosan and 5-ASA drug shown figure 4(B).

PXRD Analysis:

X- ray diffraction spectral studies of Fenugreek gum, 5-ASA and coated tablets were carried out for to study the crystallinity and possible polymorphic transformations in the formulation, showed in figure 4(C). The P-XRD results were in good agreement with the thermal analysis data. Pure 5-ASA was clearly in crystalline state as it showed sharp distinct peaks notably at 2θ° diffraction angles of 11.29, 17.71, 21.78, 23.56, 32.25, 36.38, and 39.24 2θ values. X-ray diffractogram of coated tablets show few peaks of 5-ASA, which were strongly suppressed. Characteristic peaks of fenugreek gum were observed in diffractogram of coated tablets indicating presence of Fenugreek gum but with reduced intensity. Thus, XRD spectra indicate that the developed coated tablets formulations having less crystalline in nature.

CONCLUSION:

This study presents a new approach for colonic delivery of drug by using fenugreek gum and chitosan. The release the drug in the controlled manner at appropriate pH. In FTIR studies presence of peak at 1569.3 cm^-1 and 1440.1 cm^-1 indicated the existence of –NH³⁺ ions and –COO^- ions, respectively, thus indicating the presence of ionic interaction between –NH³⁺ moieties of chitosan and –COO^- moieties of fenugreek gum. The importance with these ionic interactions does not change the properties of 5-ASA drug and allows the drug release in the colon. The tablets coated with 7% concentration of fenugreek gum and chitosan as coating solution shows desire drug release in the colon. The tablets were coated with fenugreek gum and chitosan in the ratio 70:30 allows only 10% drug release in the stomach. This indicates that the fenugreek gum and chitosan in the ratio 70:30 shows a lag phase of around 5-6 h. In vitro drug release around 89.99% at 10 h indicating better drug release in the colon as compared to other concentrations. Thus, it can be concluded that developed fenugreek gum and chitosan coated tablets can be considered as a promising system for targeted delivery of 5-ASA to Colon for local action.

ACKNOWLEDGEMENTS:

Authors are also grateful to Dr. H. N. More, Principal, Bharati Vidyapeeth College of Pharmacy, Kolhapur for providing excellent facility to carry out this work. We are also grateful to Cipla Ltd. Mumbai for providing gift sample of 5- amino salicylic acid.

CONFLICT OF INTEREST:

“The authors declared no conflict of interest”

AUTHOR CONTRIBUTIONS:

The author designed and performed the experiment, analyzed data and prepared the manuscript. All authors played an equal role in completing this research work.

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Received on 14.05.2021 Modified on 21.11.2021

Research J. Pharm. and Tech 2022; 15(10):4490-4498.

DOI: 10.52711/0974-360X.2022.00753