Applications in transdermal and dermal delivery

1 Potential mechanisms for improved dermal/transdermal transport 

2 Microemulsions as smart dermal/transdermal delivery vehicles 

The number of studies reported on the utility of the micro emulsions is the highest for dermal delivery. Numerous studies are reported in the literature which establish the utility of the microemulsions to improve the transdermal delivery of APIs. However, only some important examples will be discussed in this chapter. 

Lidocaine is a local anaesthetic which is available as a free base and hydrochloride salt. Lidocaine base is known to form eutectic mixture with prilocaine base and this eutectic mixture forms a dispersed phase of EMLA emulsion cream. Shukla et al. reported that with the help of microemulsification, the drug loading can be increased from 5% (present in EMLA cream) to 20% which may result in quick action by virtue of higher concentration gradient across the skin [49]. 

Last but not least, Changez etal. have explored the potential oflecithin-based microemulsions in improving the transdermal delivery of tetracaine hydrochloride and compared 

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