Transdermal patches with drug substances

Transdermal patches are marketed worldwide with the drug substances glycerole trinitrate, estradiol, testosterone, clonidine, scopolamine, fentanyl and nicotine, respectively. The patch has to remain for up to one week at the appropiate body site. In this case the drug amount in the reservoir is rather high. As liquid crystalline vehicles with lamellar microstructure have... 

The study should be a randomized, controlled, repeat patch test study that compares the test patch with the innovator patch. Placebo patches (transdermal patch without active drug substance) or high- and low-irritancy controls (e.g., sodium lauryl sulfate 0.1% and 0.9% saline) can be included as additional test arms. 

In membrane diffusion systems the polymer membrane with a given pore size or pore size distribution controls the diffusion of the active substance from the drug reservoir. Dosage forms with membrane-controlled drug delivery can be coated tablets, coated granules or pellets, or so-called multiparticulate systems on which various coats are applied. One possibility for transdermal drug administration is the transdermal patch controlled with a membrane [4-7,34-39]. 

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