Nonlinear oscillatory shear tests of pressure-sensitive adhesives (PSAs) designed for transdermal therapeutic systems (TTS)

Transdermal therapeutic systems (TTS) based on pressure-sensitive adhesives (PSAs) allow for the application of pharmaceutical substances via diffusion through skin. The rheological performance PSA is largely investigated within small amplitude oscillatory shear (typically up to 1 %), although skin motions exceed strains beyond 40 %. In this paper, amine-compatible (AC) and non-amine-compatible (NAC) silicone-based compounds differing in resin content were subjected strain sweeps a twin drive rheometer. Carreau-Yasuda-like fitting storage loss moduli curves intercepts substantial effect both compounds; four times higher, AC determined SAOS, their higher molecular mass combined with enhanced interactions contributed an earlier transition nonlinear viscoelastic region. range, elastic viscous properties are affected by different manner trend favorable as TTS. third relative harmonic from Fourier transformation I3/1 well intra-cycle stiffening thickening ratios provide information relevant optimization large deformations.