[Drug technology of a parenteral preparation for trimethoprim monotherapy]

The formulation of Trimetoprim (TBP) injection has been studied. Use of N-N'-dimethylacetamide in nonaqueous medium, propylene glycol, N-beta-hydroxyethyl-lactamide-propylene glycol and Macrogol--400 resulted in the preparation of the solution in appropriate concentration. In the presence of adequate quantity of ascorbic acid the TBP is soluble in 0.8% concentration. It was experimentally proved that the equimolar ratio is optimal for the TBP-ascorbic acid combination. After the preparation of the solution and lyophilized formulas the presence of TBP-ascorbic acid adduct has been proved by derivatographic and NMR spectroscopic techniques. It has been found that the lyophilized formula is stable without decomposition for six years.