About the equivalence between different batches of a glycopeptide drug.

Context: Teicoplanin is a glycopeptide antibiotic consisting of a combination of different active components. Clinical equivalence between different batches of this drug is not guaranteed by the present pharmacopeial specification of chemical composition based on an HPLC chromatogram.

Objective: To test a modification of this specification and to evaluate independent compositions recently published in the literature.

Materials And Methods: The expectable area under the plasma curve of each batch has been estimated based on its chemical composition as described in a former paper. Batch-comparisons are based on ratios between the area of the test batch and the area of a reference.

Results And Discussion: The modification of this specification recently proposed by the European Medicines Agency (EMA) has been tested confirming its goodness. A new acceptance range of AUC variation, rounding -10% to +15%, has been obtained. It is narrower than the current interval of the pharmacopeial specification. Concerning the generic batches that have been studied, the majority of differences with the reference is lower than ±10%. Variations in the compositions of the reference product have been observed to influence the results and a control criteria are proposed.

Conclusion: The variability of the pharmacokinetic performance of teicoplanin can be better controlled with this new proposal of composition specification given by EMA.