Quality of essential drugs in tropical countries: evaluation of antimalarial drugs in the Brazilian Health System.
BACKGROUND
The emergence of drug resistance is one of the main problems concerning malaria treatment. The use of counterfeit and/or substandard antimalarial drugs can contribute to the development of parasite resistance. Thus, the aim of this study was to evaluate the quality of antimalarial drugs distributed in Brazil.


METHODS
Samples containing chloroquine phosphate, mefloquine hydrochloride, primaquine phosphate, and quinine sulfate tablets were delivered to the Rio de Janeiro central storeroom (CENADI), state storerooms (SS), and Basic Health Units (BHUs) in the north region of Brazil - a total of 10 sample sets. After 5 months of storage, the samples were collected, and in vitro quality control analyses according to official and published methods were performed.


RESULTS
Inadequate drug storage conditions were found in two SS and in all BHUs evaluated. There were no quality deviations found in the chloroquine samples. The quinine samples exhibited weight variation above the allowed limits. The primaquine samples were found to have packaging deficiency. The release of mefloquine in samples from some regions showed a statistically significant difference when compared with the CENADI samples.


CONCLUSIONS
It is important to periodically evaluate the quality and storage conditions of essential drugs. The quality deviations found with the primaquine and quinine samples are not related to storage conditions and must be addressed urgently. The decreased mefloquine release from tablets is related to formulation problems or influenced by inadequate storage conditions, prompting further investigation. Even with the mentioned problems, the samples would probably not contribute to resistant parasite selection.
Departamento de Produtos Farmacêuticos, Universidade Federal de Minas Gerais, Brazil. fhanogueira@gmail.com
Fernando Henrique Andrade
FH
Nogueira
Lígia Maria
LM
Moreira-Campos
Roseli La Corte Dos
RL
Santos
Gerson Antônio
GA
Pianetti
D000962:Antimalarials / Q000592:standards*; D001938:Brazil; D002738:Chloroquine / Q000592:standards; D002851:Chromatography, High Pressure Liquid; D004356:Drug Storage / Q000592:standards*; D018954:Drugs, Essential / Q000592:standards*; D006801:Humans; D015767:Mefloquine / Q000592:standards; D011319:Primaquine / Q000592:standards; D011786:Quality Control; D011803:Quinine / Q000592:standards
D000962:Antimalarials; D018954:Drugs, Essential; D002738:Chloroquine; D011803:Quinine; D011319:Primaquine; D015767:Mefloquine