Development of Novel Skin Mimetic Substrate to Assess the Adhesion Properties of Transdermal Patches

Abstract

Abstract The objective of the present study was to develop novel skin mimetic substrates using 3D Fused Deposition Modeling (FDM) printing using materials with similar surface energy as skin and evaluate the adhesion property of pressure-sensitive adhesives (PSAs). Additionally, the objective was to study the effect of various intrinsic factors, including coat weight, elastic properties of backing membranes, and viscosity of PSAs on adhesion properties of PSAs. Our novel 3D-printed polypropylene (PP) probe was successfully printed and postprocessed using FDM printing coupled with an automated robotic arm setup for adhesion testing. Probe tack test results showed no significant difference in peak adhesive force in case of skin and PP probes. However, PP probes showed about a 10.26-fold decrease (p < 0.0001) in the adhesive force compared to the SS probe. Probe tack and peel adhesion tests of the marketed Salonpas patch also showed a significant decrease (p < 0.0001) in the adhesive force in case of PP as compared to the SS probe/plate. Effect of coat weight using PP probe results revealed that both amine (PSA-4302) and non-amine (PSA-4501) compatible silicone PSAs showed significant (p < 0.05) increase in their adhesion prosperities at 10 mg/cm2 as compared to 5 mg/cm2 coating. Further, the choice of backing membrane and viscosity of silicone PSAs also showed a significant (p < 0.0001) effect on the PSA’s adhesion property. In conclusion, PP probes/plates could be a promising approach for in vitro adhesion testing of TDS products. Further, intrinsic properties, including coat weight and viscosity of silicone PSAs, significantly affected their adhesion properties.