Evaluation of paromomycin sulphate permeation using ex vivo human skin model

Area of Science:

• Pharmacology
• Dermatology
• Infectious Diseases

Background:

• Leishmaniasis is a significant global health concern requiring effective topical treatments.
• Paromomycin sulfate is an established antileishmanial agent, but its topical delivery needs optimization.
• Current topical formulations and their skin penetration efficacy require further investigation.

Purpose of the Study:

• To evaluate the ex vivo drug release and skin permeation of paromomycin sulfate from topical formulations.
• To compare the efficacy of a paraffin-based ointment and a microemulsion-based emulgel for delivering paromomycin sulfate.
• To assess the potential of these formulations for treating cutaneous leishmaniasis.

Main Methods:

• Ex vivo drug release and skin permeation studies were conducted using intact full-thickness human skin.
• Potency-based microbiological assays were employed to quantify paromomycin concentrations.
• Drug recovery and permeation percentages into deep skin layers were analyzed after 1 and 3-hour incubation periods.

Main Results:

• A total drug recovery of 86% ± 26% was achieved.
• Permeation into deep skin layers ranged from 1.3% ± 0.04% to 5.3% ± 2.0% for the paraffin-based ointment.
• Permeation ranged from 1.6% ± 0.8% to 3.9% ± 1% for the microemulsion-based emulgel, significantly higher than previously reported with animal models.

Conclusions:

• Topical formulations of paromomycin sulfate demonstrate measurable skin permeation in an ex vivo human skin model.
• Microemulsion-based emulgels may offer superior delivery of paromomycin sulfate compared to paraffin-based ointments.
• These findings support the potential of topical paromomycin sulfate for treating leishmaniasis, warranting further clinical investigation.