The objective of this dissertation is to study regulatory and quality control aspects to tackle medicines’ counterfeiting in Guatemala. The motivation to reinforce Guatemala’s National Quality System by identifying vulnerabilities in the country’s pharmaceutical regulatory system has led the Guatemalan Finance Ministry to seek cooperation. The Postgraduate Programme in Metrology for Quality and Innovation of the Catholic University of Rio de Janeiro (PUC-Rio) offered the infrastructure within the context of quality control assessment to carry out this investigation. The methodology includes a literature survey to investigate the main themes of this work, and a case study to assess analytical methods to identify and quantify the content of camptothecin and its derivatives (irinotecan and topotecan) used in cancer treatment. A comparison between the Brazilian and Guatemalan regulatory framework was made. A critical evaluation of the analytical methods applied to the above mentioned substances was made. Conclusions have shown that vulnerabilities in the regulatory framework favor the manufacturing, trade and indiscriminate use of counterfeit drugs. Furthermore, analytical methods play an important role in its characterization. Capillary electrophoresis and espectrofluorimetric proved to be more efficient than other methods for determining counterfeit or substandard drugs of the substances studied. Most scientific studies indicate a wide range of validation parameters, but only one of them mentioned the uncertainty associated with the analytical signal of the analites of interest.