ABSTRACT
BACKGROUND AND OBJECTIVE: Patients are increasingly requiring their medications to be repackaged into dose administration aids because of the positive outcomes associated with reduction in medication related hospitalization and adverse effects due to improved medicines management. Since the stability of these repackaged medications is not the responsibility of manufacturer, it is important that drug substances with potential stability issues be identified. Thus the objective of this study was to evaluate the stability of prochlorperazine, a light sensitive drug repackaged into dose administration aids (DAAs), in order to provide guidelines to the pharmacist and advice to the patient on appropriate storage. METHODS: Prochlorperazine tablets were stored repackaged in DAAs and in their original packaging for 8 weeks at ambient (25 +/- 1 degrees C; 60 +/- 1.5% RH), accelerated (40 +/- 1 degrees C; 75 +/- 1.5% RH) and in-use conditions encountered in situ both in a pharmacy and the patients' home. They were assessed for both chemical (using a validated HPLC method) and physical stability according to British Pharmacopoeial (BP) standards. In addition, photostability testing was undertaken under ICH conditions. RESULTS AND DISCUSSION: Chemical and physical stability was confirmed to be within BP Limits. There were, however, noticeable organoleptic changes in the tablets stored under in-use conditions with a progressive grey discolouration over the 8 weeks, starting in week 2. CONCLUSION: Despite the confirmation of physical and chemical stability within BP limits, the discoloration and the potential for photodegradants to cause adverse effects in patients must lead us to draw the conclusion that the quality of this medication has been compromised. Pharmacists thus need to take this into account in repackaging and storage of prochlorperazine in DAAs and advise patients to store their DAA protected from light, heat and humidity.
Subject(s)
Antipsychotic Agents/administration & dosage , Drug Packaging , Prochlorperazine/administration & dosage , Antipsychotic Agents/analysis , Antipsychotic Agents/standards , Chemistry, Pharmaceutical , Chromatography, High Pressure Liquid , Drug Stability , Drug Storage , Hardness , Light , Prochlorperazine/analysis , Prochlorperazine/standards , Quality Control , Reference Standards , TabletsABSTRACT
Parameters associated with the separation of antianxiety-antispasmodic agents were investigated using high-pressure liquid chromatography. Eight widely prescribed drugs were studied. The compounds were chromatographed on reversed-phase octadecyltrichlorosilane (C18) or diphenyldichlorosilane (phenyl) columns, using mixtures of absolute methanol and distilled water buffered with ammonium dihydrogen phosphate, ammonium acid phosphate, or ammonium carbonate. A mixture of phenobarbital-propantheline bromide was selected to demonstrate the utility of the separation and quantification method. The mixture was chromatographed on a phenyl column, using absolute methanol-aqueous 1 percent ammonium dihydrogen phosphate (60:40) (pH 5.85) at a flow rate of 1.4 ml/min. Each determination can be achieved in approximately 15 min with an accuracy of 1-2 percent.
