Formulation and evaluation of piperine-loaded ultra-small unilamellar carrier

Background: Piperine is an alkaloid that has a stimulatory effect on the proliferation and dentricity of melanocytes. Therefore, it is a potential drug for vitiligo. Objectives: To formulate an Emulgel containing piperine-loaded Ultra-Small Unilamellar Carrier (USUC) with virgin coconut oil, soy lecithin and tween 80, and to evaluate the physicochemical properties. Method: Piperine-loaded USUC was formulated using a spontaneous water phase titration method at a stirring speed of 1500 rpm for 15 minutes with a base composition of 2.3% oil phase, 1% surfactant and 2.3% co-surfactant. Emulgel preparations were made by mixing USUC piperine into a 5% carbopol base. Result: Piperine-loaded USUC was obtained in the form of spherical globules with a Z-average size of 15.0 nm, a zeta potential of -39.5 mV and a polydispersion index of 0.312. The emulgel preparation has a pH of (6.5 ± 0.1), and a viscosity (of 44.800 ± 0.367) cP and is physically stable. Permeation of piperine from USUC emulgel follows zero-order kinetics (y = 0.130x-2.027; R2 = 0.9998) with a flux value of (3.408 ± 1.110) µg/cm2/hour, which is significantly different from permeation of non-USUC piperine gel (0.000 ± 0) µg/cm2/hour)(p <0.05). Conclusion: Piperine-loaded USUC in emulgel formulation produced nanosized spherical globules, indicating a significantly different amount of permeated piperine compared to conventional piperine gel.