Definitions of medicine quality.

For the compendial tests, the limits for compliance described in the respective USP 41 monograph were used. As proposed in the QAMSA study by the WHO¹³ and also applied in our previous study in southern Togo,³¹ samples deviating from USP 41 specifications for assay and/or dissolution were further divided into those showing only moderate deviations from the pharmacopoeial limits and those showing extreme deviations. Extreme deviation was defined as an API content deviating by more than 20% from the declared amount and/or an average dissolution of the API of the tested units falling more than 25% below the pharmacopoeial limit (i.e., below the pharmacopoeial Q value minus 25%).¹³ Table 1 shows the limits for compliance given by USP 41 for all investigated types of medicines and the limits for extreme deviations.

For the definition of falsified medicines, the current WHO definitions were used.¹² Results of GPHF Minilab TLC and disintegration testing were classified as pass/fail following the instructions of the GPHF Minilab manual.¹⁵