Chemically stable compositions of a pharmaceutical active agent in a multi- chambered delivery system for mucosal delivery

A kit for mucosally administering a metastable supersaturated solution of a pharmaceutical active agent to a human patient includes a first compartment comprising a first composition comprising a pharmaceutical active agent in solution at or below equilibrium solubility, and a second composition comprising an acidic buffer. The first and second compartments maintain separation of the first and second compositions during storage, and allow for mixing of the first and second compositions to form a supersaturated solution above equilibrium solubility of the pharmaceutical active agent for immediate mucosal administration to a human patient. In one embodiment, the second composition comprises an acidic buffer and the supersaturated solution has an acidic pH. Alternatively, the second composition comprises a basic buffer and the supersaturated solution has a basic pH.