Silicone Polymers in Scar Remediation: The Role of Migration of Oligomers Through Stratum Corneum

Abstract

A cross-linked silicone gel for burns scar rehabilitation has been analyzed to determine the oligomeric species that may migrate from the gel into skin. From MALDI–MS (matrix assisted laser desorption ionization–mass spectrometry) these were shown to be hydroxyl-terminated linear oligomers with a mass of up to 2100 Da. The migration of the extracted oligomers through stratum corneum has been determined by breakthrough times using ATR–FTIR (attenuated total reflection Fourier-transform infrared) spectroscopy. The upper value of the estimated diffusion coefficient of 2.5 × 10−9 cm2 s−1, determined from a breakthrough time of 31 h, is similar to that of large hydrophobic solutes, but penetration times from the silicone gel are low (7–10 days) due to the lower concentration of oligomers partitioning into the lipid bilayer of the skin in an aqueous environment.