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Rabeprazole sodium is highly acid-labile and presents many formulation challenges and to protect it from acidic environment of the stomach an enteric coated tablet formulation is tried in the present study. This study is aimed to develop pharmaceutically equivalent and stable enteric-coated tablets of Rabeprazole sodium comparable to innovator product. Different Formulations of Rabeprazole core tablets were developed using mannitol as diluent and croscarmellose as super disintegrant in different proportions. Further optimized formulation was coated with varying the compositions of sub coating and enteric coating using opadry white and enteric yellow. Compatibility studies were performed for drug, physical mixture tablet which shows no interaction. From the dissolution the formulation F6 shows highest percentage of drug release. The kinetics of drug release for F6 & Innovator followed first order and 'n' value (0.5>n<1) shows that the mechanism may be erosion control rate release. The f1 and f2 were found to be 3.03 and 72.01 respectively for formulation F6 and innovator product. Hence these two products were considered similar and comparable. In the accelerated stability testing carried out at 40°c and 75% RH for three months, no significant change in the physical properties, drug content, and dissolution rate of formulation F6 was observed. From this it can be concluded that formulation F6 developed is found to be an efficient delayed release formulations of Rabeprazole comparable to the innovator product. Thus the study fulfilled the objective of developing efficient Rabeprazole delayed release tablets.

In the present work, double walled microspheres of Tamoxifen (antiestrogenic drug) using Sodium alginate, Hydroxy propyl methyl cellulose (HPMC) K100,Guar gum, Xanthun gum were formulated to deliver Tamoxifen (TMX) through  oral route to treat breast cancer patients. Details regarding the preparation and evaluation of the formulations have been discussed in results. From the study following conclusions could be drawn. The results of this investigation indicate that Ion gelation method can be successfully employed to fabricate TMX microspheres. FT-IR spectra of the physical mixture revealed that the drug is compatible with the polymers and copolymer used. Microspheres containing sodium alginate along with HPMC in 1:1 ratio had a least size range of 610µm. Increase in the polymer concentration led to increase in % Yield, % Drug entrapment efficiency, Particle size. The  invitro drug release decreased with increase in the polymer and copolymer concentration. Among all formulations F7 shows Maximum drug release in 12 th hr  when compared with other formulations. Analysis of drug release mechanism showed that the drug release from the formulations followed the Non fickian diffusion mechanism and follows zero order kinectics. Based on the results of evaluation tests formulation coded F7 was concluded as best formulation. Keywords : Tamoxifen, sodium alginate, HPMC, Microspheres, Diffusion, Copolymers,  Entrapment efficiency.

In present work Colon targeting drug delivery system was developed for Busulfan an anticancer drug by using combination of delayed systems one is pH dependant and other is time dependant delayed system.  Rapid release core tablet (RRCT) formulations were prepared using Busulfan drug with different disintegrating agents in different concentrations. The pre-compression and post-compression parameters of all formulations were determined and the values were found to be satisfactory. From the In-vitro dissolution studies, F6 formulation with 12% Hydroxy propyl cellulose (HPC) was the best formulation. For optimized RRCT formulation press coat was done by using Xanthum Gum and Ethyl Cellulose (EC) in different ratios. Press coated tablet delays the drug release up to 8 hours based on the nature and concentrations of the polymer. Each press coated tablet was coated using enteric solution made of HPMC phthalate, Myvacet and color dissolved in ethanol. Enteric press coated tablets (EPCT) were delayed drug release up to 2hrs in fed condition due to pH dependant delayed system.  Based on dissolution studies of EPCT formulations, C3OPF formulation was optimized and showed delayed release pattern in a much customized manner. As a result of this study it may be concluded that the colon targeted drug delivery tablets using a combination of two polymers in optimized concentrations can be used to increase the delayed action of drug release to deliver the drug in a delayed manner. Key words: Colon, RRCT, HPC, Xanthum gum and EPCT

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