Formulation and Evaluation of Nanoparticle Based Drug Delivery System for Antihypertensive Drugs

Abstract

Telmisartan is a potent angiotensin II receptor blocker extensively prescribed for the treatment of hypertension. However, its therapeutic efficacy is compromised by poor aqueous solubility, slow dissolution rate, and low oral bioavailability, classifying it as a Biopharmaceutical Classification System (BCS) Class II drug. The present study aimed to formulate and evaluate Telmisartan-loaded polymeric nanoparticles using the solvent evaporation technique to improve its dissolution behavior and enhance oral drug delivery. Poly(lactic-co-glycolic acid) (PLGA) was employed as the biodegradable polymer, while polyvinyl alcohol (PVA) served as the stabilizing agent. Preformulation studies, including solubility analysis, melting point determination, UV spectrophotometric method development, and drug-excipient compatibility studies, were performed. Compatibility was further confirmed using Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). The prepared nanoparticles were evaluated for percentage yield, drug loading, entrapment efficiency, particle size, polydispersity index (PDI), zeta potential, surface morphology, in vitro drug release, release kinetics, and accelerated stability. The optimized formulation exhibited a mean particle size of 198 nm, PDI of 0.214, and zeta potential of −32.8 mV, indicating a stable and uniformly dispersed nanosystem. FTIR and DSC analyses confirmed the absence of significant drug-polymer interactions and demonstrated reduced crystallinity of Telmisartan within the PLGA matrix. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) revealed spherical nanoparticles with smooth surfaces and uniform distribution. The optimized formulation achieved high drug entrapment efficiency and approximately 96.8% cumulative drug release, showing a significant improvement in dissolution compared with the pure drug. Drug release followed the Higuchi kinetic model, suggesting diffusion-controlled release from the polymeric matrix. Stability studies demonstrated that the formulation remained physically and chemically stable under accelerated storage conditions. Overall, the findings indicate that PLGA-based polymeric nanoparticles prepared by the solvent evaporation method represent a promising and effective approach for enhancing the dissolution, stability, and oral bioavailability of Telmisartan.