Development of a Combined Solution Formulation of Atropine Sulfate and Obidoxime Chloride for Autoinjector and Evaluation of Its Stability

ABSTRACT

Atropine [AT] and oximes, alone or in combination, have been proven greatly valuable therapeutics in the treatment of organophosphates intoxications. An injectable mixture of AT andobidoxime [OB] was formulated for the administration by automatic self-injector. The aqueous single dose solution contained 275 mg obidoxime chloride and 2.5 mg atropine sulfate per 1 mL [220 mg and 2 mg per 0.8 effective doses, respectively]. The final solution was sterilized by filtration through a 0.22 µm pore size filter. This more concentrated solution allowed using a smaller size and lighter weight cartridge. Quality control tests, including assay of the two major compounds were performed separately, using reversed-phase HPLC methods. Besides, the stability test was carried out according to ICH guideline for the accelerated test. The obtained results showed that the proposed formulation is stable over a period of 2 years after preparation