Stability of frusemide tablets repackaged in dose administration aids

Abstract

Background: Repackaging tablets into a dose administration aid (DAA) requires that the pharmacist consider the stability of the active pharmaceutical ingredient and the excipients of the drug product. Frusemide is susceptible to photodegradation and is commonly repackaged into DAAs. Aim: To evaluate the stability (chemical and physical) of frusemide tablets repackaged into DAAs. Method: Frusemide tablets repackaged into DAAs were evaluated for physicochemical stability over a period of 8 weeks at a controlled room temperature (25 +/- 2 degrees C) and other relevant in-use conditions. In addition, photostability studies were performed according to the International Committee on Harmonisation (ICH) guidelines. Results: Chemical stability was confirmed for all storage conditions, including the ICH light conditions, with the frusemide content within the British Pharmacopoeia's range of 95 to 105%. Although the physical stability was confirmed by all tests (weight uniformity, hardness, friability, disintegration, dissolution), storage in a simulated pharmacy environment after one week and exposure to ICH light conditions resulted in a yellow colouration of the tablets. Conclusion: Although the chemical and physical stability of frusemide was within acceptable limits during the study, the discolouration of the tablets from light exposure is unacceptable. It is recommended that DAAs are stored protected from light immediately after repackaging with frusemide tablets, and that patients are counselled to store the DAA in a cool dark place.