Zinc oxide is a common additive in food, cosmetics, and medicines. Here, we describe the validation of methods to analyze two pharmaceutical samples containing ZnO--talc powder and dermal ointment--by ethylenediaminetetraacetic acid (EDTA) titration. The methods developed were implemented as a practical class to students of a Quantitative Analysis course, and the statistical analysis of the results were performed with the students in order to compare experimental results with label information. The practical class allowed students to see an interesting application of EDTA titration in quality control and provided better practical comprehension of important contents in complexometric titrations, statistical analysis, and laboratory techniques.