The Distribution of Diclofenac Sodium in Porcine Skin: A Quantitative Approach Using Franz Diffusion Cells and Tape Stripping

Abstract

While transdermal drug delivery techniques have advanced over the years, there are still gaps in understanding how different drugs pass through the skin. This project aims to address one of these gaps by investigating the permeation behavior of diclofenac sodium (DS) through the porcine ear skin at different time intervals, using Franz diffusion cells and tape stripping. Porcine skin, known for its similarities to human skin, was used along with Franz diffusion cells to measure drug permeation. Tape stripping (TS) was implemented for drug quantification in the stratum corneum—the rate-limiting barrier in percutaneous absorption. Data obtained from these techniques, combined with the results from the remaining dermis and subcutaneous fat layer, provided a more comprehensive assessment of the distribution profile of DS—from the donor chamber through the skin and into the receptor chamber. Initial analysis using a high-performance liquid chromatography (HPLC) instrument was limited by sensitivity. Subsequently, the analysis was switched to an ultra-performance liquid chromatography (UPLC) instrument, which demonstrated more than 37-fold sensitivity than the HPLC instrument. The UPLC results, along with those from the ultra-high performance liquid chromatography (UHPLC) instrument, demonstrated that the permeation and distribution of DS could be effectively tracked, with detection levels reaching the 90th percentile. Although a decrease in the diffusion coefficient was observed, drug accumulation in both the skin and receptor solution increased over time. These findings suggest that DS may be more effective as a long-term transdermal patch, potentially leading to improved therapeutic outcomes and better long-term patient compliance.