Evaluation of paromomycin sulphate permeation using ex vivo human skin model

Ex vivo evaluation of drug release and skin permeation from topical formulations of antileishmanial drug paromomycin sulphate was carried out using intact full thickness human skin. Potency-based microbiological assay was used for the analysis of paromomycin concentrations. A total percentage drug recovery of 86 +/- 26% was obtained. Incubation periods of 1 and 3h resulted in percentage drug permeation into deep skin layers ranging from 1.3 +/- 0.04% to 5.3 +/- 2.0% with paraffin-based ointment and from 1.6 +/- 0.8% to 3.9 +/- 1% with microemulsion-based emulgel. Although a small percentage, this is still significantly higher than those previously reported using animal skin models.