title: Use of refractometry and colorimetry as field methods to rapidly assess antimalarial drug quality.
abstract: The proliferation of counterfeit and poor-quality drugs is a major public health problem; especially in developing countries lacking adequate resources to effectively monitor their prevalence. Simple and affordable field methods provide a practical means of rapidly monitoring drug quality in circumstances where more advanced techniques are not available. Therefore, we have evaluated refractometry, colorimetry and a technique combining both processes as simple and accurate field assays to rapidly test the quality of the commonly available antimalarial drugs; artesunate, chloroquine, quinine, and sulfadoxine. Method bias, sensitivity, specificity and accuracy relative to high-performance liquid chromatographic (HPLC) analysis of drugs collected in the Lao PDR were assessed for each technique. The HPLC method for each drug was evaluated in terms of assay variability and accuracy. The accuracy of the combined method ranged from 0.96 to 1.00 for artesunate tablets, chloroquine injectables, quinine capsules, and sulfadoxine tablets while the accuracy was 0.78 for enterically coated chloroquine tablets. These techniques provide a generally accurate, yet simple and affordable means to assess drug quality in resource-poor settings.
authors.affiliation: Division of Parasitic Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, United States. mgreen@cdc.gov
authors.forename: Michael D
authors.initials: MD
authors.lastname: Green
authors.forename: Henry
authors.initials: H
authors.lastname: Nettey
authors.forename: Ofelia
authors.initials: O
authors.lastname: Villalva Rojas
authors.forename: Chansapha
authors.initials: C
authors.lastname: Pamanivong
authors.forename: Lamphet
authors.initials: L
authors.lastname: Khounsaknalath
authors.forename: Miguel
authors.initials: M
authors.lastname: Grande Ortiz
authors.forename: Paul N
authors.initials: PN
authors.lastname: Newton
authors.forename: Facundo M
authors.initials: FM
authors.lastname: Fernández
authors.forename: Latsamy
authors.initials: L
authors.lastname: Vongsack
authors.forename: Ot
authors.initials: O
authors.lastname: Manolin
mesh_terms: D000962:Antimalarials / Q000032:analysis*; D037621:Artemisinins / Q000032:analysis; D000077332:Artesunate; D002738:Chloroquine / Q000008:administration & dosage / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003124:Colorimetry; D007202:Indicators and Reagents; D011786:Quality Control; D011803:Quinine / Q000032:analysis; D012015:Reference Standards; D012031:Refractometry; D012717:Sesquiterpenes / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet; D013413:Sulfadoxine / Q000032:analysis
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D007202:Indicators and Reagents; D012717:Sesquiterpenes; D000077332:Artesunate; D013413:Sulfadoxine; D002738:Chloroquine; D011803:Quinine