The present investigation was done based on the many frequencies of drug taken orally per single day so, for altering the dose frequency of the drug delivery for the colonic diseases diclofenac sodium was loaded with the microsponges. The colonic targeted microsponges are prepared by acid resistant polymers such as eudragit L100, eudragit RS 100, eudragit EPO 100. These acid resistant polymers release the drug for controlled manner and site specific action. Diclofenac sodium was incorporated into microsponges which help in controlled release of the diclofenac sodium. The polymer used for the preparation of microsponges was useful in forming sponges in which drug was entrapped. FT-IR studies were performed and from the FT-IR spectra it was evident that there were no interactions between the diclofenac sodium and polymer. Formulations of microsponges were prepared by quasi-emulsion solvent diffusion technique using eudragit L100, eudragit RS 100 and eudragit EPO 100 in various ratios such as (1:0.5, 1:1, 1:2 and 1:2). By using the 3 polymers 12 formulations were prepared from the 12 formulations 3 formulations were selected as optimized formulations based on the production yield(%),drug loading(%), encapsulating efficiency and in vitro drug release studies (90.4.7%). Hence, it was proposed that diclofenac sodium microsponges having porous structure and drug release is controlled by predetermined rate. By comparing these three formulations (L2, S3, EPO1) L2 formulation containing EL100 gives the best results.

The objective of the present work is to design sustained release matrix tablets of Cefixime Trihydrate by incorporating drug in a matrix made up of release retardant polymers, which prolongs the drug release leading to minimize the peak and valley effect in the plasma and provide patient convenience. The effect of combination of polymers on parameters like release pattern, release mechanism of the drug were studied. Total nine formulations each containing 200 mg of drug were prepared by direct compression method. The formulations F-1, F-2, F-3 were prepared 1:1 drug to polymer ratio using HPMC, sodium CMC and Ethyl cellulose. F-4 was prepared by 1:1 ratio of HPMC and sodium CMC ,F-5 was prepared by 1:1 ratio of HPMC and Ethyl cellulose, F-6 was prepared by in 1:1 ratio of sodium CMC and Ethyl cellulose, F-7, F-8, F-9 were prepared by using polymers HPMC, sodium CMC and Ethyl cellulose in the ratios of (0.5:0.5:1), (0.5:1:0.5), (1:0.5:0.5). Designed matrix tablets evaluated for various pre-compression and post-compression parameters. Formulation F-5(1:1 ratio of HPMC and Ethylcellulose) showed 102.15 % release at the end of 12 hours and it is selected as the best formulation. All Formulations follows zero order with nonfickian diffusion method.

Janakidevi and Ramanamurthy: Development of Colon-targeted MicrospongesThe present study is aimed to develop and characterize microsponge-based novel colon-specific drug delivery systems containing 5-amino salicylic acid for the treatment of inflammatory bowel disease. Initially, microsponges of 5-amino salicylic acid were prepared by quasi-emulsion solvent diffusion method using Eudragit RS100, Eudragit S100 and Eudragit L100. Different formulations of microsponges using three acid resistant polymers, Eudragit S100, Eudragit L100, Eudragit RS100 in drug:polymer ratios of 1:1, 1:0.5, 1:0.25 with each polymer were prepared and evaluated for physicochemical, morphological characteristics and in vitro parameters. Among these nine formulations, ES1, EL1 and ERS1 were selected, sieved and compressed into tablets, T-ES1, T-EL1, T-ERS1 and evaluated. Among the 3 batches of tablet formulations prepared, T-ES1 showed the best release rate for the drug, which followed zero order release kinetics with diffusion case-II transport mechanism.