The present invention generally relates to transdermal delivery and, in particular, to transdermal delivery using nanoemulsions and other emulsions. In one aspect, the present invention is directed to emulsions comprising a first, continuous phase and a second, discontinuous phase. The first phase may be an aqueous liquid and the second phase may comprise a lipid, such as isopropyl myristate. In some cases, a surfactant, such as Pluronic® L61, is used to stabilize the emulsion. Surprisingly, it has been found that such emulsions are effective at delivering pharmaceutically active agents, such as ciprofloxacin, when the formulation has a very low water content, for example, less than 30 wt % or less than 10 wt %. This is surprising because high water contents—not low water contents—are typically correlated with greater transdermal drug delivery, and thus, a low water content would have been considered to be unfavorable for facilitating transdermal drug delivery.