Development of Haloperidol in Oil Injection Formulations

Abstract

Several aliphatic acids were evaluated as solubilizers for haloperidol in eight oils representative of oils employed as depot, i.m. injection vehicles. The six acids which were adequately soluble (0.5 M) in the oils in order to solubilize haloperidol to 40 mg/mL were liquids which solidified at <5°. Saline precipitated haloperidol from all solutions except those prepared with oleic and linoleic acids. The release kinetics of haloperidol from the oleic acid/oil and linoleic acid/oil solutions into saline followed the theory for release from an inert, homogeneous matrix. The slowest release rates were achieved with oleic acid/corn oil, sesame oil, neutral oil and myristate esters. The slowest rates were 3 to 4 times faster than the release rate of haloperidol decanoate from a sesame oil formulation which is clinically effective upon monthly i.m. administration.