Household Storage Methods and the Stability of Medicines in Tropical Countries: A Narrative Review

Abstract

The storage conditions utilized by the consumers are a significant factor that can affect the quality and efficacy of medicines. This narrative review aimed to identify the places of medicine storage in the households of the tropical region and to find how the stability of medicines depends on those conditions. The review was conducted by retrieving original full-text research articles published from 2000 to 2021 written in English on the home storage of medicines in tropical countries (n=11) and in-vitro stability studies relating to tropical conditions (n=30). Scopus, PubMed, and Google Scholar were searched using keywords.; 'in-vitro stability,' 'home storage,' 'medicine (drug),' 'stability,' and 'quality’. Search strings were developed using Boolean operators ‘AND & OR'. Articles were categorized into two classes (class I- home storage of medicines, and class II- in-use stability of medicines). The studies on veterinary, extemporaneous, co-administered, and combined drugs were excluded. Percent mean values of common storage places were calculated based on the results of class I studies. The reported in-vitro stability test results were explored, summarized, tabulated, and discussed. Results showed that consumers store medicines at convenient places to use with minimum stability considerations. About half of the study population reported using safe storage places (cupboard, bedroom, wall shelves/drawers & pill containers). In contrast, 49.18% used locations (bag/purse, kitchen, living room/sitting room, refrigerator, dining table, bathroom, car, storeroom, envelops & clothes’ pockets) with a high probability for temperature and humidity deviations. In-vitro studies showed failures in the physical, chemical, and microbiological quality of medicines stored under extreme environmental conditions. Results varied depending on the storage conditions, type of packaging, and period of home storage. The use of poor repacking materials in bulk dispensing and long-term prescriptions should be discouraged. Patient education on proper medicine storage would help preserve the stability of medicine during home storage.