PhD Scientific Days 2022

Pharmaceutical Sciences II. (Poster discussion will take place in the Aula during the Coffee Break)

Use of an in vitro skin parallel artificial membrane assay (Skin-pampa) as a screening tool to compare transdermal permeability of 4-phenylethyl-resorcinol dissolved in different solvents

Text of the abstract

In the development of topical formulations, especially during the early stages, it is important to investigate absorption through the skin. However, the supply of human skin is limited, and the traditional in vitro methods have low throughput. Skin Parallel Artificial Membrane Permeability Assay (Skin-PAMPA) provides an alternative solution. It has been developed to mimic the permeability through the stratum corneum. In our study, this assay was used to measure the permeability of a model compound, 4-phenylethyl-resorcinol (PER). The PER was dissolved in 13 different solvents, that are commonly used in cosmetic formulation development. On the one hand the aim of the research was to prove that the method works as a suitable screening test for solvents with different physicochemical properties. On the other hand to the effect of solvents on permeability was investigated. The study was performed using such concentrations, which are close to the saturated solution of PER in each solvent. It makes it possible to investigate the maximum thermodynamic potential of the solvents. During the 6-hour measurment period, samples were taken at predetermined times to establish permeability profiles. For comparison, the permeability of PER in selected solvents was also measured on ex vivo pig skin, which is an accepted alternative model of human skin. The permeability coefficient, which is independent of the concentration of the applied solution, showed a good correlation (R2 = 0.844) between the Skin-PAMPA and the pig skin permeation data. Our results support the use of the Skin-PAMPA to screen the suitability of different solvents for non-polar compounds at an early stage of formulation development.