Formulation Development and in-vitro Evaluation of Sulfasalazine and Dexamethasone Combination Tablets Containing Natural and Semi Synthetic Polymer for Colon Targeting

摘要

The present research was to develop oral sustained release tablets for colontargeting. Two drugs in combination form were used in this researchto prepared tablets. Combination of sulfasalazine and dexamethasoneused with natural and semi synthetic polymers (tragacanth and HPMCK15). Sustained release matrix tablets of sulfasalazine and dexamethasonewere prepared by using different ratios of drug, HPMC K15 and tragacanth.Microcrystalline cellulose (MCC) and lactose were used as diluents. Bothpolymers were mixed with other ingredients and formed a matrix systemusing direct compression technique. All the ingredients of formulationwere compressed using concave punches in ZP 19 compression machine.Compressed tablets were evaluated for assay, diameter, hardness, thickness,friability, weight variation and in vitro dissolution using USP dissolutionapparatus type II. Different formulations were prepared and evaluatedwith respect to dissolution profile in 900 mL 0.1 N Hcl and phosphatebuffer pH 6.8 and pH7.4 including microbial flora for 12 h at 37ⅹC. Risingthe amount of polymer (HPMC K15) in the formulation led to slowrelease of drug and decreasing the amount of polymer gave enhancedrelease of sulfasalazine and dexamethasone. Different mathematical modelsused to evaluate the matrix system (Zero order, First order, Higuchi andHixson-Crowell). T5, T7, T8 solid matrix formulations followed zero orderand Higuchi. The results showed that the formulation T7 containing 17%HPMC K15 and 17% gum tragacanth gives better results in microbial florawith phosphate buffer.