Stability of aqueous suspensions of disulfiram.

The stability of disulfiram in aqueous suspension is reported. Aqueous suspensions of disulfiram were prepared from bulk powder and from disulfiram tablets. Acacia and sodium benzoate were present in the suspension, the final concentration of which was 25 mg/ml disulfiram. Suspensions were stored in amber bottles under fluorescent light at 24 degrees C for 178 days (tablets) and 295 days (bulk powder). Samples were taken at various intervals during storage and assayed by high-pressure liquid chromatography (HPLC) and a modified NF method. Both types of suspension were stable. Potency remained constant, and no new peaks appeared in the chromatograph. Physical integrity of the suspensions was maintained. The suspension made from tablets contained less foam and air than the one made from bulk powder; both types were easily dispersible. A degradation product of disulfiram, diethyldithiocarbamic acid, did not interfere with the assay. The HPLC assay method was more reproducible than the modified NF method. Aqueous suspensions of disulfiram are stable at room temperature for the indicated time periods, and the HPLC assay method for disulfiram is reproducible and accurate.