This pilot study was conducted as a prelude to a comprehensive study on the quality of antimalarials and the complex issues involved. The critical methodological and analytical considerations highlighted in this report should be taken into account when planning further studies. This means:

• Working closely with the analytical laboratory during the planning phase of such a study in order to accommodate the analytical laboratory's needs regarding sample and analytical information, sample containers, and the quantities of sample needed.

• Products should not be taken from the original packaging material in which they are marketed. The use of other packaging material than that used by the manufacturer for sampling may compromise the integrity of the product.

• The storage and transport of samples after sampling should be validated to assure the stability of the samples.

• A standard operational procedure should be used to guide sampling and handling of sampled products in order to standardize procedures in all countries. Where possible, the formulation of the product and/or the analytical method that the manufacturer uses for batch release should be made available to the analytical laboratory. This is in order to assure the specificity of the analytical method to be employed by the testing laboratory.

• More emphasis should be given to dissolution of solid dosage forms, as this gives an indication of the pharmaceutical availability and interchangeability of products.

• Tests for preservative efficacy should be considered for liquid dosage forms.