Drug release permeation mechanism

The basic physical parameters of polymeric matrices prepared by simple physical mixing of drug and polymer powders are reviewed The wettability of the matrix, its pore structure and the permeability of the polymer particles resulted to be the controlling factors in the overall penetration process and in the subsequent drug release mechanism A simple experimental approach to the identification of the penetration mechanism is proposed, which allows to distinguish between a capillary driven penetration and a diffusion controlled permeation process ... 

Tokudome, Y., and K. Sugibayashi. 2004. Mechanism of the synergic effects of calcium chloride and electroporation on the in vitro enhanced skin permeation of drugs. J Control Release 95 (2) 267. 

A new generation of transdermal drug delivery (TDD) system was developed to contain one or more skin permeation enhancers in the surface adhesive coating layers. This TDD system has been found, experimentally, to release the enhancers to the surface of stratum corneum to modify the skin s barrier properties, prior to the controlled delivery of the active drug. The extent of enhancement in skin permeability appears to be dependent upon the chemical structure of drug to be delivered transdermally as well as the type and the concentration of enhancer used. The mechanism of skin permeation enhancement have been explored and are analyzed in this report. 

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