Pharmaceutical preparations containing highly volatile silicones

A process for the preparation of a pharmaceutical composition comprising a plurality of particles of an active pharmaceutical ingredient dispersed in a gel or cream base, the process comprising the steps of:

• coating substantially all of the particles of active ingredient with a layer of highly volatile silicone or a mixture of highly volatile silicones;
• mixing the coated particles of active ingredient with a gel or cream base;
• wherein the layer of highly volatile silicone or mixture of highly volatile silicones substantially prevents contact between the active pharmaceutical agent and the gel or cream base at least until application;
• and
• wherein the mass ratio of the layer of highly volatile silicone or mixture of highly volatile silicones to the active pharmaceutical agent is at least about 2:1.