FORMULATION AND IN VIVO EVALUATION OF SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM OF RAMIPRIL IN WISTAR RATS

Abstract

Objective: The aim was to formulate and evaluate self-nanoemulsifying drug delivery systems (SNEDDS) of ramipril, an antihypertensive drug to improve the solubility and bioavailability. Methods: Based on solubility studies oil phase (Sefsol 218), surfactant (Acrysol EL135), and cosurfactant (Transcutol P), respectively, were selected to prepare SNEDDS. Ramipril SNEDDS optimized employing box-Behnken design through the study of factors. All formulations were evaluated for particle size, zeta potential (ZP), polydispersity index (PDI), entrapment efficiency (EE), drug content, and in vitro drug release. The optimized formulation was characterized for Fourier transform infrared (FTIR), scanning electron microscopy (SEM), stability studies, and pharmacokinetic study. Results: The mean particle size, PDI, ZP, EE, content uniformity, and in vitro drug release profile of optimized ramipril-loaded SNEDDS (RF14) were found to be 75.3±2.21nm, 0.126±0.05, −24.4±5.78mV, 98.74±1.97%, 99.52±1.67%, and 98.65±1.73%, respectively. FTIR studies revealed that there is no incompatibility between drug and excipients, SEM images exhibited nanoparticles to be more porous and in spherical shape. Stability studies indicated formulation was stable for 6 months. In vivo studies were conducted for optimized formulation RF14, the Tmax was found to be 0.5±0.62 and 0.5±0.95 h for the optimized and commercial formulations respectively, while Cmax was 25.16±1.73 ng/mL was significant (p<0.05) as compared to the ramipril pure drug 8.02±0.086 ng/mL. AUC0-t of the SNEDDS formulation was higher 355.49±1.76ng h/ml compared to pure drug 116.57±1.64 ng h/ml indicated higher amount of drug concentration in blood proving better systemic absorption of ramipril from SNEDDS formulation as compared to the pure drug. Conclusion: It is concluded from the results that ramipril was successfully formulated into SNEDDS with higher concentration with fast action.