Stability of essential drugs

mended by the manufacturer, especialiy in tropical Objective-To determine whether present harbours and during inland transport. Except for methods of international transport of essential drugs ergometrine and methylergometrine the transport by sea adversely affect their quality. would not affect clinical effectiveness. Design-Controlied longitudinal study of drug shipments sent by sea from Unicef in Copenhagen to World Health Lagos; to Mombasa and by land to Kampala; and to Introduction Organisation, Action Bangkok. 11 essential drugs were stored in four In 1987 Unicef sent over $30 million worth of Programme on Essential locations on board the ships. essential drugs to tropical countries.' The stability of Drugs, 1211 Geneva-27, Setting-Main shipping routes from Unicef, medicines distributed and used in hot and humid H V Hogerzeil, MD, technical Copenhagen, to tropical countries. climates can pose serious problems, but stability officer Main outcome measures-Temperature and studies and storage guidelines usually refer to temA Battersby,AADIPL, logistics relative humidity in the test packs during the perate climates and therefore may not be relevant in consultant journey. Amount of active ingredient in the drugs extreme climatic conditions.2 Few studies have desbefore and after shipment. cribed the influence of tropical storage conditions on Unicef Supply Division, Results-Temperatures recorded within the test the quality ofmedicines.3 The World Health OrganisaFreeport, Copenhagen, packs range from -3 5°C to 42-4°C and were 3-12°C tion and Unicef therefore carried out a joint study on V Srdanovicm sca chiefof higher than the ambient temperature. Relative the stability of essential drugs during international purchasing, health, and humidity within the packs ranged from 20% to 88%. transport. nutrition Differences between the locations on board were negligible. Ergometrine injection, methylergoChemical Laboratories, metrine injection, and retinol capsules lost 1.5-5.8% Materials and methods Medical Products Agency, of their activity. Ampoules of ergometrine showed a We used three criteria to select drugs for the study. Husargatan 8,75125 large variation in the amount of active ingredient The first criterion was an indication from WHO Uppsala, Sweden after shipment, with three of 80 samples having accelerated stability tests4 or other studies5t8 that the N E Stjernstrom, PHD, head concentrations 60% below those stated. Ampicillin, active substance or the drug product could be unstable Correspondence to: benzylpeniciliin, phenoxymethylpenicillin, and in tropical climates. The other criteria were that Unicef Dr Hogerzeil. tetracycline were not affected by transport. has a high turnover of the drug in volume or in value Conclusions-Drugs were exposed to a much and in medical relevance. Eleven drugs were selected. BMJ 1992;304:210-4 higer temperature and humidity than is recoinAll samples were taken from normal Unicef stock, and 210 BMJ VOLUME 304 25 JANUARY 1992 products in the test and control packs were taken from the same batch. Three sea routes were chosen that together cover 35 of the 77 countries served by Unicef and nearly 40% of the total volume of drugs dispatched in 1987. The journeys from Copenhagen to Lagos (Nigeria), to Mombasa and overland to Kampala (Uganda), and to Bangkok (Thailand) took 51, 52, and 27 days respectively 10-30% of the time was spent in the port of destination before customs clearance. Battery operated "autolog" devices were developed that electronically measured and recorded temperature and relative humidity at three hourly intervals over 100 days. The test packs were the normal Unicef triple wall cardboard boxes containing the selected drugs and the autolog. Four test packs were included in each of the shipments and were put in different locations on board (one pack in the centre and one near the ceiling of two containers, one located in the hold and the other on deck). After arrival and clearance from customs the test packs were sent by air to the chemical laboratories of the Medical Products Agency in Uppsala, Sweden, where control packs had been kept and where the chemical analyses were done. Unfortunately, the test packs from Bangkok were returned by surface mail. The climatic recordings of that journey were used but the drugs were excuded from the analysis.