Development and Characterization of Ramipril Loaded Solid self Nanoemulsifying Drug Delivery System SNEDDS for Improved Oral Delivery of Lipophilic Drugs

SNEDDS are lipid based liquid formulations which are defined as self nanoemulsifying drug delivery systems (SNEDDS) that offer potential vehicle for improved oral delivery of poorly water soluble and low bioavailable drugs. The primary goal of the present work was to formulate solid SNEDDS (SSNEDDS) in order to improve the solubility of highly lipophilic drug Ramipril. The main intention behind choosing SNEDDS formulation for Ramipril was that lipid based formulations enhance solubility of lipophilic drugs and as a result dissolution rate and absorption may be further enhanced. SNEDDS are generally liquid form preparations obtained by homogenously mixing drug along with oils, surfactants and co-surfactants using cyclomixer. After screening various vehicles for solubility studies, Capmul MCM C8, Gelucire 50/13 and Transcutol P were selected as oil, surfactant and co-surfactant respectively in order to prepare ramipril loaded SNEDDS. Nine different liquid SNEDDS (L-SNEDDS) formulations were prepared and subjected to various evaluation tests. Out of these nine different L-SNEDDS, L-SN9 formulation was optimized as it formed thermodynamically stable emulsion without any drug precipitation and phase separation on storage and also showed least globule size (22.5nm).This optimized formulation, was loaded on to inert carrier (Sylysia FCP 350) to obtain solid SNEDDS (S-SNEDDS). They were further processed for solid state characterization such as PXRD, SEM and the results confirmed the transformation of native crystalline nature of drug to amorphous state. FTIR analysis was also performed and showed no drug-excipient interaction. Finally, Ramipril loaded S-SNEDDS formulation was successfully prepared, encapsulated in hard gelatin capsules and this formulation proved to have improved solubility for Ramipril.