Formulation and Evaluation of Microparticulate Controlled Release Solid Dosage Form of Nateglinide

C. Venkata Sai Manoj Kumar*, A. Deepthi, Dr. U. Mohan Kumar, P. Sravanthi, G. Balachandra, T. Mounika
Department of Pharmaceutics,  Nirmala College of Pharmacy, Kadapa Dist., Andhra Pradesh

A B S T R A C T
Nateglinide is a widely used oral antihyperglycemic agent for managing non-insulin-dependent diabetes mellitus (NIDDM), belonging to the meglitinide class of short-acting insulin secretagogues. Due to its rapid pharmacokinetics with a half-life of 1.5 hours, controlled release formulations have been pursued to optimize therapeutic efficacy. This study focuses on preparing Nateglinide-loaded alginate microparticles (ALG) through ionotropic gelation. The microparticles were characterized for morphology, drug loading efficiency, and in vitro release profiles under varying conditions of curing time (6 hr and 24 hr) and drug loading (10%, 15%, and 25%). Scanning electron microscopy revealed spherical particles with surface roughness, whose size increased with higher initial drug loading and slightly decreased curing time. Drug loading efficiency exceeded 82%, influenced by formulation variables. In vitro release studies in phosphate buffer (pH 7.4) demonstrated that drug release decreased with higher drug loading and longer curing times, consistently achieving rapid release within 2.5 hours. Fourier-transform infrared spectroscopy and differential scanning calorimetry indicated drug stability within the microparticles. However, the rapid release kinetics suggested that alginate alone was insufficient to control release. Future strategies involving blending with non-ionizing polymers or forming polyelectrolyte complexes are recommended to extend release duration, particularly in alkaline pH environments. This study underscores the potential of natural hydrophilic polymers for achieving controlled release of Nateglinide, advocating further exploration through clinical trials to validate these findings in therapeutic applications.
Keywords: Nateglinide, diabetes mellitus, in vitro release, meglitinide