Transdermal pharmaceutical formulation for minimizing skin residues

A transdermal or transmucosal non-occlusive pharmaceutical formulation comprising testosterone as active ingredient;

• and a solvent system present in an amount sufficient to solubilise the active ingredient and the solvent system includes:
• (i) a pharmaceutically acceptable monoalkyl ether of diethylene glycol present in an amount of between about 1% and 30% by weight of the solvent system;
• (ii) a pharmaceutically acceptable glycol present in an amount of between about 1% and 30% by weight of the solvent system, with the monoalkyl ether of diethylene glycol and the glycol being present in a weight ratio of 1:4 to 1:10;
• and
• (iii) a mixture of a C2 to C4 alcohol and water which mixture is present in an amount of between about 40% and 98% of the solvent system, wherein the C2 to C4 alcohol is present in an amount of about 5% to 80% of the mixture, and the water is present in an amount of about 20% to 95% of the mixture;
• wherein the monoalkyl ether of diethylene glycol and the glycol in combination are present in amount of at least 15% and no more than 60% of the formulation, so that, compared to formulations containing the same components but in different amounts and ratios, the present solvent system (a) inhibits crystallization of the at least one active ingredient on a skin or mucosal surface of a mammal, (b) reduces or prevents transfer of the formulation to clothing or to another being, (c) modulates biodistribution of the at least one active ingredient within different layers of skin, (d) facilitates absorption of the at least one active ingredient by a skin or a mucosal surface of a mammal or (e) provides a combination of one or more of (a) through (d).