RESUMEN
Objective: To prepare the self-microemulsion gel drug delivery system of Carthamus tinctorius extract based on Mentha haplocalyx oil as oil phase. Methods: M. haplocalyx oil was used as the oil phase, and C. tinctorius extract was used as the water phase. The prescription of self-microemulsion were optimized by pseudo-ternary phase diagram, the process and prescription of gel were screened by single-factor method and the appearance, viscosity and pH value were evaluated. Result: The optimal formulation of CTE-SMEDDS-BGs was as following: F68 was the emulsifier, anhydrous ethanol was the co-emulsifier, the Km ratio was 1:1, and the total amount of emulsifier and co-emulsifier to M. plocalyx oil was 8:2, carbopol-980 was 2%, glycerin was 6%, and C. tinctorius extract was 5 mL. The CTE-SMEDDS-BGs was obtained by adding the CTE-SMEDDS into swelling gel matrix and triethylamine was used to adjust the pH to 6.0. The characteristics of appearance were yellow translucent, moderate viscosity, uniform and delicate, non-greasy, and easy to spread on the skin, the viscosity was 4.98 × 104 mPa•s (RSD was 1.53%), pH was 6.04 (RSD was 0.44%). Conclusion: The CTE- SMEDDS-BGs with M. plocalyx oil as oil phase is simple and stable, and meets the requirements of gel topical preparations.