Preparation and In Vitro Evaluation of Sustained-Release Matrix Tablets of Flutamide Using Synthetic and Naturally Occurring Polymers

Frequent dosing of the potent anti-androgen, flutamide, is necessary to reach a therapeutic level for the treatment of prostatic carcinoma. Sustained delivery of the drug could reduce the adverse effects such as gastrointestinal disorders and improve patient compliance. In the present study sustained-release matrix tablets of flutamide were prepared by direct compression method using different polymers. Cellulose ethers (HPMC and NaCMC), natural gums (guar and xanthan gums) and compressible Eudragits (RSPO and RLPO) and their combinations were used in different ratios to examine their influence on tablet properties and drug release profile. Tablets were evaluated by measurement of hardness, friability, content uniformity, weight variation and drug release pattern. All the tablets met the pharmacopoeial requirements for physical tests, based on USP 29. Almost in all formulations, with increasing the percentage of polymer, release rate decreased, though drug release pattern was mainly dependent on the type of polymer. Formulations H2F4 (contained 25% HPMC) and S3F4 (contained around 40% RSPO) met the desired requirements for a sustained-release dosage form. These two formulations released their drug content with a first order kinetic.