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

The in-use stability study in this paper was designed as far as possible to simulate the practical usage of multi-dose containers products in veterinary practice and to establish the influence of storage conditions on drug's quality. According to literature data, shelf-live of enrofloxacin solutions for injection tested in this study is 28 days after opening. In-use (open container) stability testing of enrofloxacin injection solutions was studied during a period of 112 days, and the physical-chemical parameters and microbiological contamination were assessed. A spectrophotometric method was validated for the quantification of enrofloxacin. 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 (0.18 μg/mL), limit of quantification (0.54 μg/mL) and accuracy. The results of spectrophotometric analyses were presented as the mean drug concentration of enrofloxacin vs. time of sampling. The findings of physical, chemical and microbiological parameters were in accordance with the producers' specifications and no extreme changes during prescribed storage occurred. The study was extended from the drug's proposed shelf-life after opening for the next 84 days and in that period no significant changes were recorded.