Controlled release - over at least 4-15 days - of injectable compositions comprising a lipophilic counterion such a saturated or unsaturated C10-C18 fatty acid

摘要

Provided are compositions and methods for extending the release times and lowering the toxicity of pharmacologically active compounds. The compounds comprise a salt of the pharmacologically active compound with a lipophilic counterion and a pharmaceutically acceptable water soluble solvent combined together to form an injectable composition. The lipophilic counterion may be a saturated or unsaturated C8-C22 fatty acid, and preferably may be a saturated or unsaturated C10-C18 fatty acid. When injected into a non-human mammal, at least a portion of the composition precipitates and releases the active compound over time. Thus, the composition forms a slowly releasing drug depot of the active compound in the mammal. Therefore, controlled dose administration of the active compound is provided for a period of up to 15 days or longer. Many compounds can be administered including, but not limited to, tilmicosin, oxytetracycline, metoprolol, fluoxetine, roxithromycin, and turbinafine. Figure 3 is a graphical depiction illustrating that the rate of release of the pharmacologically active compound, tilmicosinm is affected by the chain length of the fatty acid selected. Solvent: N-methyl pyrrolidone; lipophilic counterion: decanoic acid and lauric acid.