Dermal drug delivery, microemulsions

Shukla, A., Krause, A. and Neubert, R.H.H. (2003) Microemulsions as colloidal vehicle systems for dermal drug delivery. Part IV Investigation of microemulsion systems based on a eutectic mixture of lidocaine andprilocaine as the colloidal phase by dynamic light scattering. /. Pharm. Pharmacol., 55, 741-748. 

Shukla, A., Janich, M., Jahn, K., and NeuberL R.H.H. 2003 Microemulsions for dermal drug delivery studied by dynamic light scattering Effect of interparticle interactions in oil-in-water microemulsions, J. Pharm. Sci. 92 730-738. 

In addition to traditional dermal and transdermal delivery formulations, such as creams, ointments, gels, and patches, several other systems have been evaluated. In the pharmaceutical semisolid and liquid formulation area,these include sprays, foams, multiple emulsions, microemulsions, liposomal formulations, transfersomes, niosomes, ethosomes, cyclodextrins, glycospheres, dermal membrane structures, and microsponges. Many of these novel systems use vesicles to modulate drug delivery. Novel transdermal... 

The cosmetics and transdermal drug delivery fields are also expected to further benefit from the formulation of microemulsions from mild sugarbased surfactants. Lehmann et al. have studied the effect of such a microemulsion on dermal and corneal irritation, and hydrocortisone incorporation [105]. A microemulsion containing commercially available sucrose esters, isopropyl myristate, and propylene glycol and water was prepared as a water continuous system, and 16.5% hydrocortisone was loaded into the anhydrous base mixture. The formulation spread well on the skin due to the low surface tension of the system at 26 mN/m. While the microemulsion provided greater drug penetration, it also resulted in irritation and barrier compromise. The authors make the point that the formulation may be better suited to drugs that do not induce an irritation themselves. 

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