The quality of medicines in less developed countries is often poor due to a lack of quality assurance during manufacture, excessive decomposition of active ingredients under hot and humid conditions, and/or counterfeiting. Nonetheless, substandard and expired drugs continue to circulate because of simple economics, lack of adequate drug information, and weak country-level drug regulatory systems. In one study conducted by the Department of Pharmacy of the University of Nairobi, 46 percent of locally manufactured products were substandard when their active ingredient was measured by compendial methods (Kibwage et al., 1992). In another study, almost half of nearly 600 antimalarial, antibacterial, and antituberculosis drugs purchased in Lagos or Abuja, Nigeria did not comply with set pharmacopoeial limits. The sample included chloroquine, sulfadoxine/pyrimethamine (SP), and quinine tablets, and chloroquine and SP syrups, some of which had less than 25 percent active ingredient (Taylor et al., 2001). Failure to dissolve was found in 44 and 13 percent respectively of SP and amodiaquine tablets sold by private wholesale pharmacies in Dar es Salaam, Tanzania (Minzi et al., 2003). These findings validate consumers’ concerns about antimalarial drug quality in many malaria-endemic countries.
In contrast to a substandard drug, a counterfeit drug is one that has been incorrectly packaged or constituted in a deliberate attempt to dupe sellers and consumers (Wondemagegnehu, 1995). Among cases in which pharmaceutical preparations contain no active ingredient, a drug other than that stated on the label, or consistently low concentrations of drug, fraud is the most likely cause (Wan Po, 2001). Counterfeit artesunate and mefloquine preparations are widely sold in Cambodia (Rozendaal, 2001). Another recent study from Southeast Asia found that more than a third of tablets labeled “artesunate” purchased from shops in Cambodia, Laos, Burma, Thailand, and Vietnam contained no drug (Newton et al., 2001). Recognizable packaging is one means of increasing the likelihood that drugs are authentic, although it does not eliminate the need to verify quality using, for example, drug testing kits. In Southeast Asia where counterfeit packaging changes frequently, this type of testing must be conducted on a regular basis (Newton et al., 2001).
Labeling of pharmaceuticals, malaria drugs included, is woefully inadequate in many malaria-endemic settings. When drugs are accompanied by printed information, the information is often written in complicated or technical language, or, in some cases, a language entirely unknown to the