Enhancing the solubility of ramipril using a new essential oil based microemulsion system

Ramipril is a good angiotensin converting enzyme (ACE) inhibitor. This drug is found to be poorly aqueous insoluble due to its lipophilic nature. But the efficacy of the drug directly depends on the solubility. Hence, we tried to improve on the solubility using a new lipophilic environment. Our novel microemulsion drug delivery system for ramipril was formulated using cinnamon oil, tween 20 and water (6:30:64 v/v) without any high-energy methods. The optimized formulation was checked for various parameters to demonstrate the internal state of the system. Cinnamon oil based drug-incorporated system (F5) showed higher solubility, hydrodynamic diameter of 9-48 nm and good stability. Also, the surfactant concentration was found to have a direct relation to stability and viscosity. Moreover, the system due to the presence of cinnamon oil may have additional influence on the efficacy against certain pathogens. Thus, our novel formulation has added advantage in serving as best drug delivery agent for ramipril.