Effect of tocopherol on Pluronic microemulsions: turbidity studies and Dynamic light scattering and dynamic surface tension measurements

The development and design of the biocompatible and biodegradable thermodynamically stable micellar and microemulsion transparent dispersions to reduce the free and unbounded drugs concentration in the blood is a basic challenge in field of drug efficacy and bioavailability of drugs. In the current work, solubilization capacity of the drug (Tocopherol), oil (Ethyl Butyrate), and oil+drug (1:1 molar ratio) into F127 pluronic microemulsions was studied as a function of F127 concentration through simple turbidity or transparency experiments. Pluronic F127-based oil-in-water microemulsions of various compositions were synthesized and titrated with concentrated Tocopherol drug, Ethyl Butyrate oil, and oil+drug (1:1 molar ratio), separately, to determine clear /turbid transition zone. We observed that, at certain Pluronic F127 concentrations , microemulsions were gel-like. This specific concentration of F127 was different for three systems mentioned. We also observed that by increasing sodium caprylate fatty acid in the system , solutions became transparent. By the simple logic, we were able to determine the optimal binding ratio of F127 and/or SC to ethyl butyrate oil, Tocopherol drug, and oil+drug (1:1 molar ratio) in microemulsion. We also measured the dynamic surface tension and dynamic light scattering of the microemulsion formulations to further prove the hypothesis that all fatty acid is bound to the F127 in the microemulsion.