Trans-dermal formulations

Although sensitising properties can be also detected in the classical development program of a drug substance, the need for dermal sensitization studies is of importance for the development of certain drugs. The increasing importance of trans-dermal formulations demonstrate the need of testing for dermal sensitization on the one side, on the other side, there are classical examples which cause dermal sensitization (e.g. neomycin, procaine, sulphonamides). 

In light of the recognized importance of achieving stable, reproducible plasma concentrations of drugs, particular attention is given to pathways and devices, including sustained-release formulations, pumps, and trans-dermal entry processes that ensure such properties. 

Pyrrolidones show activity with numerous molecules including hydrophilic (e.g., mannitol, 5-fluorouracil, and sulfaguanidine) and lipophilic (betamethasone-17-benzoate, hydrocortisone, and progesterone) permeants. As with many studies, higher flux enhancements have been reported for the hydrophilic molecules. Recently, NMP was employed with limited success as an absorption promoter for captopril when formulated into a matrix-type trans-dermal patch [20]. 

Solid lipid nanoparticles have been investigated in many different administration routes parenteral, oral, (trans)dermal, ocular d64,i97 pulmonary.Furthermore, cationic SLN formulations were used to complex DNA for cell transfection. In the following chapter, selected studies are summarized with respect to a parenteral, oral and dermal administration as well as for gene delivery to illustrate the versatility of solid lipid nanoparticle formulations in drug delivery. 

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