Analytical Chemistry as a Bridge Between Theory and Practice: A Multidisciplinary Laboratory Exercise Using Complexometric Titration of Commercial Zinc Dietary Supplements

Laboratory education in pharmacy should enable students to perform analytical procedures and critically interpret findings within a broader professional context. This study proposes a three-hour multidisciplinary laboratory exercise for senior pharmacy students, revisiting complexometric titration previously learned in Analytical Chemistry through the analysis of commercial zinc dietary supplements. Students work in pairs to calculate apparent zinc contents using EDTA titration, process data, compare results with label claims, and apply pharmacopoeial content uniformity concepts as educational benchmarks. Guided discussion connects analytical findings with formulation composition, dietary supplement regulation, and the distinction between supplements and medicines. Preliminary experiments with acid-dissolved model zinc compounds assessed linearity, recovery, and selected excipient effects. Direct titration of five commercial supplements yielded apparent zinc contents corresponding to 95.79–136.84% of label claims. Quantitative recovery and freedom from matrix interference were not established for the commercial formulations; these results therefore support discussion of method limitations rather than confirmed assessments of product quality. The contribution lies in using an established, accessible technique to connect analytical chemistry, pharmaceutical technology, bromatology, and regulatory science through authentic samples and critical data interpretation. The proposed framework offers opportunities for multidisciplinary learning, while its educational effectiveness requires structured assessment.