A composition for topical application to a part of the body comprises a vasodilator, for example glyceryl trinitrate, as active ingredient dissolved in a blend of volatile and non-volatile solvents of different solvating capacities for the vasodilator. The vasoldator is present in the composition at a concentration at or slightly below saturation, whereby evaporation of the volatile solvent in use will maintain the vasodilator at saturated or super-saturated concentrations in the residue, whereby the vasodilator will become saturated or supersaturated in the solvent remaining and, as the active ingredient passes through the skin and is absorbed in the bloodstream, and thus becomes depleted in the residual composition, continuing evaporation of volatile solvent will maintain the active ingredient substantially at saturation or supersaturation level in the residual composition throughout the major part of the absorption phase, thereby maximising absorption levels but at a moderate dosage level.
