Nanoemulsion as a tool for improvement of Cilostazol oral bioavailability

Cilostazol (CLZ) is a well known therapeutic agent which is used for antithrombotic activity but suffers from the drawback of poor oral bioavailability. Research studies have explored the utilization of various lipid based formulations like nanoemulsions to overcome such limitations. CLZ nanoemulsions were produced by aqueous titration technique to improve the oral bioavailability. CLZ solubility in oils and emulsifiers was estimated to select the excipients for the formulation. Triacetin and Capryol 90 (1:1) were used as the hydrophobic phase. Amongst various surfactants and co-surfactants, CLZ showed solubility of 4.0 ± 0.2 mg/ml and 8.0 ± 0.04 mg/ml in tween 80 and transcutol P, respectively and therefore they were selected for the formulation of nanoemulsions. Results of droplet size for optimized batch were found to be 93.72 nm. CLZ nanoemulsions exhibited polydispersity index (PDI) of 0.278. Enhanced CLZ release was obtained with nanoemulsions. Pharmacokinetic studies showed that the optimized nanoemulsion (X1) showed 3.29 times improvement in bioavailability in comparison to CLZ suspension.