Preparation and Physicochemical Characterization of a Diclofenac Sodium-Dual Layer Polyvinyl Alcohol Patch.

The aim of this study is to prepare a dual layer polyvinyl (PVA) patch using a combination of electrospinning techniques and cryogelation (freeze-thaw process) then subsequently to investigate the effect of freeze-thaw cycles, nanofiber thickness, and diclofenac sodium (DS) loading on the physicochemical and mechanical properties and formulation of dual layer PVA patches composed of electrospun PVA nanofibers and PVA cryogel. After the successful preparation of the dual layer PVA patch, the prepared patch was subjected to investigation to assess the effect of freeze-thaw cycles, nanofiber thickness and percentages of DS loading on the morphology, physiochemical and mechanical properties. Various spectroscopic techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), water contact angle, and tensile tests were used to evaluate the physicochemical and mechanical properties of prepared dual layer PVA patches. The morphological structures of the dual layer PVA patch demonstrated the effectiveness of both techniques. The effect of freeze-thaw cycles, nanofiber thickness, and DS percentage loading on the crystallinity of a dual layer PVA patch was investigated using XRD analysis. The presence of a distinct DS peak in the FTIR spectrum indicates the compatibility of DS in a dual layer PVA patch through in-situ loading. All prepared patches were considered highly hydrophilic because the data obtained was less than 90°. The increasing saturation of DS within the PVA matrix increases the tensile strength of prepared patches, however decreased its elasticity. Evidently, the increasing of electrospun PVA nanofibers thickness, freeze-thaw cycles, and the DS saturation has improved the physicochemical and mechanical properties of the DS medicated dual layer PVA patches, making them a promising biomaterial for transdermal drug delivery applications.