The outcome of topical dermatological therapy depends on drug potency,
topical bioavailability and patient adherence to treatment regimen. A basic
understanding of the physicochemical (drug and vehicle) and physiological (skin at
treatment site, anatomic site variation in permeability, age and metabolic activity)
parameters that govern skin absorption is critical to topical dermatological therapy. An
understanding of these parameters can enhance efficacy and reduce or eliminate side
effects due to local and/or systemic exposure to drug or vehicle components
(excipients). Studies have shown that patients do not prefer the use of an inconvenient
and messy topical preparation even if justified by the drug’s effectiveness since the
treatment may adversely affect patients’ quality of life. For topical therapy to be
successful, it is imperative that healthcare practitioners discuss with patients the
advantages and limitations associated with the different vehicle options available for a
topical dermatological drug. Such an approach ensures that patients’ desires and
preferences are central to the treatment regimen and are therefore expected to improve
patient adherence to treatment and treatment outcome. This chapter provides a summary
of the physiological and physicochemical aspects of topical drug absorption and
methods of optimizing topical dermatological therapy (including the use of
microspheres, occlusion by dressings, spray and foam vehicles).
Keywords: Therapeutics, drug therapy, drug delivery systems, drug carriers,
pharmaceutical vehicles, drug administration routes, administration, topical,
administration, cutaneous, skin, dermis, epidermis, stratum corneum, dermatological
vehicles, topical efficacy, topical bioavailability, topical foams.
