COMPATIBILITY AND STABILITY STUDIES OF EXTEMPORANEOUSLY PREPARED FUROSEMIDE IN SYRUP BP

Introduction: The use of incompatible and unstable preparations endangers therapeutic treatment and could lead to treatment failure, in other to obtain a desired therapeutic outcome, extemporaneous preparations should be compatible and stable with the suspending vehicle. Objective: The purpose of this study is to determine suitability of syrup BP as a vehicle in furosemide extemporaneous preparation. Methods: The compatibility study between furosemide and syrup BP was achieved using FTIR spectroscopy. Functional groups in the mixture of furosemide and syrup FTIR spectrum were compared with those in the FTIR spectrum of furosemide alone. An ultraviolet method for the quantification of furosemide in extemporaneous preparation was adopted and validated for linearity, precision, and accuracy as per ICH guidelines. Extemporaneous preparations of furosemide syrup BP (2 mg/ml) were prepared using furosemide standard powder and furosemide tablet in syrup BP as vehicle. The samples were stored under different conditions, including room temperature, refrigeration (4±2◦C), and alternating storage conditions. The stability of the preparation was determined as the percentage of furosemide degradation. Results: There is complete superimposition of the IR spectrum of the mixture of furosemide in syrup BP from 0 to 21 days, indicating no chemical interaction between the two substances. The validated method was linear, accurate, repeatable, and reproducible. All preparations were stable after three weeks, with a percentage degradation rate less than 10%. High rate of degradation was observed on samples stored at room temperature and alternating storage compared to those stored under refrigeration. Conclusion: Furosemide was found to be compatible and stable in syrup BP for a period of three weeks when stored under the three storage conditions. However, the optimum storage condition was found to be refrigeration.