ABSTRACT
INTRODUCTION The merits of topical application of medicines have been well documented (1-5). Topical dosage forms intended for local effects have the advantage of facilitating drug delivery to the site of interest to produce a local therapeutic effect while avoiding or minimizing systemic side effects. However, not all drugs are suitable candidates for topical administration due to their physicochemical properties amongst others (6). Ideally, a suitable drug candidate for topical use should have a low molecular mass (<500 Da), high lipophilicity (log P in the range of 1-3), low melting point (<200◦C), and high potency (<50 mg/day). Nevertheless, the relative ease of use and increased patient acceptance of topical formulations have made their use widespread (7) and many products for topical administration are currently available. Commercially available topical products include antibacterials, antifungals, antivirals, nonsteroidal anti-inflammatories, analgesics, corticosteroids, and also local anesthetics.
