DEVELOPMENT AND EVALUATION OF FLOATING GASTRORETENTIVE MICROPARTICLES OF NIFEDIPINE

ABSTRACTBackground: Nifedipine is a poorly water-soluble calcium channel blocker with a relativelyshort biological half-life and marked photosensitivity. Floating gastroretentivemultiparticulate systems may provide prolonged gastric residence and controlled drug releasewhile offering protection against photodegradation.Objective:The current work used ethyl cellulose, Eudragit E100, and stearyl alcohol asformulation components to create and optimize nifedipine-loaded floating gastroretentivemicroparticles.Methods: Nifedipine floating gastroretentive microparticles were prepared by a modified oilin-water solvent diffusion–evaporation method. Drug release, entrapment efficiency, andparticle size were the responses in a three-factor Central Composite Design (CCD) that usedethyl cellulose, stearyl alcohol, and Eudragit E100 as independent variables.Seventeenformulations were prepared and evaluated for particle size, percentage yield, entrapmentefficiency, micromeritic properties, swelling index, buoyancy and in-vitro drug release. Theoptimized formulation was further evaluated for release kinetics and photostability.Results:With an overall desirability of 0.912285, the improved formulation included 400 mgof ethyl cellulose, 40 mg of stearyl alcohol, and 75 mg of Eudragit E100. It showed anentrapment effectiveness of 93.5%, a percentage yield of 81.3%, and a particle size of 81.2µm. At six and twenty-four hours, the swelling index was 68.4% and 94.7%, respectively,while the buoyancy was 71.6% and 86.3%. At 0.5 hours, cumulative drug release was 11.8%;at 24 hours, it was 87.6%. The Korsmeyer-Peppas model produced a n value of 0.406,although the first-order model displayed the strongest correlation coefficient (R² = 0.9643).Drug degradation was 57.70% for the optimized microparticles and 87.86% for purenifedipine after 7 hours of UV exposure.Conclusion: The optimized nifedipine floating gastroretentive microparticles demonstratedprolonged drug release, satisfactory floating and swelling behaviour and improvedphotostability compared with the pure drug. The developed system may therefore serve as apotential multiparticulate gastroretentive delivery system for nifedipine.