ABSTRACT
The broad spectrum of topical preparations in use today vary in their physicochemical nature from powders to liquids to semisolids. While early topical formulations were often crude mixtures of chemicals, the drug delivery vehicles commonly used today attempt to achieve a balance between the physicochemical requisites for stability, preservation against microbial spoilage, and release of the active ingredient to the stratum corneum; in addition to ensuring the esthetics and user-acceptability of the formulation.
