In-use stability of enrofloxacin solution for injection in multi-dose containers

Abstract

Objectives The in-use stability study in this paper was designed as far as possible to simulate a practical usage of the multi-dose containers products in veterinary practice and an influence of storage conditions on quality of drug's active substance. Methods In-use stability testing of enrofloxacin (ENRO) as an active substance in Veterinary Medicinal Products (VMP's) was studied during a period of 115 days. Appropriate quantities of VMP's were removed by the withdrawal method regularly used and described in the product literature. The physical-chemical parameters and microbiological contamination in the multi-dose containers of injectable solutions of ENRO were assessed. The differences among various injectable solutions and differences among their batches and shelf-lives were analysed. A spectrophotometric method was modified and validated for quantification of ENRO in injectable solutions. Key findings The validation method yielded good results and included the selectivity, linearity, intra-assay precision (1.26 % RSD), inter- assay precision (1.52 % RSD), limit of detection (0.17 μg/mL), limit of quantification (0.57 μg/mL) and accuracy. Results of in–use stability testing on injectable solutions were presented as the mean drug concentration of ENRO vs. time of sampling. Conclusions ENRO assays of batches within proposed shelf-life (28 days) and batches out of proposed shelf-life were within producer's decelerated content and no extreme changes during prescribed storage were occurred. Study was extended from the drug's proposed shelf-life for next 87 days and in that period no significant changes of ENRO assay was occurred either.