Mapping of medicines storage conditions in warehouses and retail outlets in Tanzania

Abstract

Background: As global warming is now widely accepted as a reality, temperature and humidity are likely to become ever more of a problem in warehouses and outlets as far as storage conditions are concerned. Hence storage conditions mapping becomes of critical importance in order to ensure that the great debate among different stakeholders on whether the prescribed labelled storage conditions for medicines can be achieved in the real market supply chain facilities Study Objectives: To assess temperature and relative humidity storage conditions in Tanzania for the Good Storage Practice of medicines according to the International Committee on Harmonization (ICH). The information obtained from this study will help to advice the regulatory Authority on the stability requirements and letting for Tanzania. Methods: The study involved selected warehouses and retail outlets. These were six public warehouses and six private medicine outlet facilities which include medical stores department warehouses, Government hospital warehouses/pharmacies and community warehouses/pharmacies. Data collection involved a site visit to mount digital temperature and humidity data loggers, which were programmed to automatically collect, and record twice per day i.e mid-day at 12:10 hrs and mid-night at 00:10 hrs conditions over a period of one year. In the current study, the storage conditions were determined through calculation of the mean kinetic temperature and the arithmetic mean relative humidity (RH) formula. The parameters were collected from daily point temperatures and humidity in six different geographic zones of Tanzania mainland. The data have been analyzed with the program prepared in the Microsoft Excel 2007 using the MKT formulae; and data presented in tables and graphs. The analysis for temperature and relative humidity data were calculated by using the mean kinetic temperature and arithmetic mean formula respectively. Results: A total of 8760 data reading each for temperature and relative humidity were collected for one year. The overall Mean Kinetic Temperature for Tanzania mainland calculated value was 25.63 oC and the arithmetic mean relative humidity calculated was 60.2%. The highest temperature value was recorded in the Coastal zone (34.1 oC) and lowest was in the Southern highland zone (12.05 oC). The highest relative humidity value was in the Coastal zone (89.0%) and lowest was in Southern highland zone (25.0%). Conclusion: Tanzania which covers a large area records a variation of climate, example in Northern zone and Southern highland zone the temperature is much lower compared to the Coastal zone. The storage facilities in Tanzania do comply with the Good Storage Practice of medicines according to the International Committee on Harmonization (ICH) with respect to temperature and relative humidity. The data suggest Tanzania fits well in climatic zone IVb 30 °C ± 2 °C/75% RH ± 5% RH and Zone II (25 ± 2oC/60 ±5%) according to ICH guidelines, in principle this argument holds only and only if the facility is fitted with air-conditioning. However, with the current requirement one puts low risk by considering the worst case scenario while on the other hand it would mean some good quality medicine are wasted as a consequence of underestimated shelf life. The economic loss resulting from this remains undetermined. Recommendation: The study recommends mapping of storage conditions from facilities not fitted with air-conditioning to see whether they will also comply with ICH conditions