FORMULATION AND EVALUATION OF CONTROLLED POROSITY OSMOTIC TABLET OF DILTIAZEM HYDROCHLORIDE

Diltiazem HCl is a newer class of antiarrhythmic agent and available in market tablets as a controlled and extended-release formulation. The release pattern is influenced by atmosphere, pH, the presence of food and other physiological conditions of GI tract. This is possible by formulating and osmotic tablets. A controlled porosity osmotic tablet of diltiazem HCl was formulated by incorporating leachable polymer Eudragit in a PEG-400 semipermeable coating membrane. The core tablet was prepared using the drug, mannitol, MCC, PVP K-30, talc and mg. stearate. The core tablet was evaluated using bulk and tapped density, carr’s index, angle of repose, hardness, weight variation, in-vitro dissolution. The thickness of PEG-400 coating was optimized to give a desired release of drug. The drug release study was done by USP-II dissolution apparatus (paddle). 2³ factorial design used to optimized the formulation. The release pattern was concluded from kinetics models as a zero-order release. Osmotic tablet of diltiazem can be successfully formulated using diltiazem HCl (120mg), HPMCK100M (100mg), PEG 400(20%), mannitol (3.5mg) giving 6% weight gain which give zero order release for 24 hrs.