Xanthan and alginate-matrix used as transdermal delivery carrier for piroxicam and ketoconazole.

This study presents new drug delivery systems based on xanthan, unmodified or modified by esterification with oleic acid, and alginate for controlled release of bioactive substances with anti-inflammatory (piroxicam) and antifungal properties (ketoconazole). The mechanical properties of the developed drug carriers showed that their compressive strength was affected by the encapsulation of the bioactive principles. When ketoconazole was added into the xanthan/alginate matrix, an increment in the mechanical strength was recorded (66.68% compression). The release of the active principles from the materials was best described by the Korsmeyer-Peppas model, with non-Fickian or Fickian diffusion (the values of the exponent of release are between 0.29 and 0.75), depending on the composition of the polymeric matrix. The release rate constant presents smaller values for the materials based on chemically modified xanthan (between 0.89 and 20.11) as compared with materials based on the unmodified form (between 4.27 and 25.00). All materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The designed systems prove to have antimicrobial and anti-inflammatory activity. The findings make prone these biomaterials for the manufacture of transdermal drug delivery systems.