Development of piperine nanoemulsions: an alternative topical application for hypopigmentation.

This study, it was aimed to develop a topical piperine nanoemulsion (P-NE) using an ultrasonic emulsification process to find an alternative treatment option for some hypopigmentation disorders such as vitiligo. Results showed that 150 mg piperine loaded NE with 1:2 oil phase to Smix ratio and manufactured with 20 min ultrasonication duration with the pre-emulsification step was the most durable formulation with a mean globule size of 216.00 ± 2.65, a PdI value of 0.094 ± 0.02 and a zeta potential value of -27.50 ± 2.48 mV. After three months of storage, the selected P-NE (coded as F3P2) remained kinetically stable without visual changes. This formulation displayed a sustained release pattern with a release of 81.92% ± 3.04% piperine after 72 h. According to our in vitro activity experiments, it was determined that the P-NE had no toxic effect including the dose of 5 mg/mL, and the highest P-NE formulation dose of 5 mg/mL increased tyrosinase activity by 32.77% ± 9.09% and melanogenesis activity by 34.90% ± 0.73%. In conclusion, it was demonstrated that the P-NE formulation may serve as a promising therapy for the efficient treatment of vitiligo. Moreover, P-NE formulation may also help in preventing irregular pigmentation and skin cancer, associated with the conventional treatment methods.