Oil and liquid silicone foamable carriers and formulations

A waterless foamable pharmaceutical composition, comprising a foamable carrier and at least one liquefied or compressed gas propellant wherein the foamable carrier comprises:

• a) about 60% to about 95% by weight of at least one liquid oil selected from the group comprising mineral oil, MCT oil, liquid paraffin, vegetable oil, essential oil, organic oil, lipid, or a mixture of two or more thereof comprising about 60-90% mineral oil;
• b) about 0.5% to about 15% by weight of a silicone;
• and
• c) about 0.01% to about 25% by weight at least one foam stabilizing agent;
• wherein the foamable carrier is substantially a single phase;
• wherein the foam stabilizing agent is selected from the group consisting of at least one surface-active agent alone, at least one foam adjuvant alone, or at least one surface active agent in combination with at least one foam adjuvant;
• and
• wherein the at least one surface active agent alone comprises glycerol monostearate or glycerol palmitostearate;
• wherein the at least one foam adjuvant alone comprises myristyl alcohol or cetostearyl alcohol;
• wherein the silicone is selected from the group consisting of a cyclic silicone, a branched silicone, a polar silicone or a mixture thereof,
• wherein the cyclic silicone is a siloxane compound having 4-6 Si—O groups in its backbone;
• or a cyclomethicone, or cyclotetrasiloxane, cyclopentasiloxane, cyclohexasiloxane or a mixture of two or more thereof;
• wherein the branched silicone is a phenyl trimethicone, stearyl dimethicone, cetyl dimethicone, caprylyl methicone, or PEG/PPG 18/18 dimethicone;
• wherein the polar silicone is a dimethiconol or PEG/PPG 18/18 dimethicone;
• wherein the composition is essentially free of water;
• wherein the ratio of the foamable carrier to the propellant is 100:03 to 100:35;
• and
• wherein the resultant foam displays the following characteristics:
• a. is at least of good quality;
• b. does not collapse immediately upon release;
• and
• c. is breakable on mechanical shear.

A method for preparing a substantially single phase, waterless foamable pharmaceutical composition, the method comprising the steps of either:

• (a) combining about 60% to about 95% by weight of at least one liquid oil with at least one foam stabilizing agent at a temperature of at least about 50° C.;
• wherein the foam stabilizing agent is selected from the group consisting of about 0.01% to about 25% by weight of at least one surface-active agent alone or in combination with a foam adjuvant;
• (b) rapidly cooling the combination of one liquid oil and at least one foam stabilizing agent to less than 40° C.;
• (c) adding a silicone to the cooled combination to make a prefoam formulation;
• and
• (d) combining the prefoam formulation with a compressed gas propellant in a weight ratio of 100:3 to 100:35;
• or
• (i) preparing a prefoam formulation by combining at a temperature of at least about 50° C.:
• about 60% to about 95% by weight of at least one liquid oil;
• a silicone;
• and
• at least one foam stabilizing agent;
• wherein the foam stabilizing agent is selected from the group consisting of about 0.01% to about 25% by weight of at least one surface-active agent alone or in combination with a foam adjuvant;
• (ii) rapidly cooling the prefoam formulation to less than 40° C.;
• and
• (iii) combining the prefoam formulation with a compressed gas propellant in a weight ratio of 100:3 to 100:35.