Development and evaluation of Self Micro-emulsifying drug delivery for rosuvastatin calcium

Bioavailability of a drug depends upon the solubility of the drug in gastrointestinal environment; most of the new chemical entities coming out through synthesis are of low solubility (less than 1 mg/ml). The oral bioavailability of Rosuvastatin calcium is less, it may be due to its low water solubility. The objective of the study is to improve solubility of Rosuvastatin Calcium by development of liquid self micro-emulsifying dosage form development. The solubility of Rosuvastatin Calcium is determined in different oils (Sefsol 228, IAS, Ethyl oleate, Olive oil, castor oil, HCO 40), surfactant ( Tween 20, Tween 80, Cremophore RH 40, Lauroglycol) and co-surfactant ( PEG 400, Propylene glycol, Transcutol P, Lutrol 400). The identification of micro emulsifying region is identified by constructing pseudo ternary phase diagram using water titration method. The optimized formulation contain oil phase as LAS (20 % w/w), Tween 20 (5 % w/w) as surfactant and co-surfactant as lutrol 400 (5 % w/w) containing 100 mg Rosuvastatin Calcium. The prepared liquid self micro-emulsion is evaluated for Phase separation (No phase separation for 24 hrs at room temperature), Self micro emulsifying time (less than 1 min), Particle size (0.2 micron), robustness to dilution (no phase separation), In-vitro dissolution study in distilled water. The in-vitro dissolution study showed improvement in solubility of Rosuvastatin Calcium over plain Rosuvastatin calcium.