COMPARATIVE STUDY OF THE POTENCY OF ANTIMALARIAL DRUGS USED ON MALE AND FEMALE PATIENTS USING BIOASSAY ANALYSIS METHOD

Background: Bioassay remains essential for evaluating antimalarial drug potency in resource-limited settings, particularly for Plasmodium malariae infections which contribute significantly to malaria morbidity in sub-Saharan Africa. Establishing parallelism between dose-response curves is a critical prerequisite for valid relative potency estimation. Objective: This study assessed the potency of four generic antimalarial brands (Drugs A, B, C, D) relative to a standard formulation using clinical recovery time data with gender-stratified analysis. Methods: An indirect assay design measured time to recovery (hours) post-treatment. Parallelism was tested using F-test, χ²-test, and equivalence testing via JMP software version 17. A 4-parameter logistic (4PL) model characterized dose-response relationships. One-way ANOVA assessed formulation variation, with bioequivalence declared when 90% confidence intervals for growth rate, inflection point, and asymptotes fell within decision limits. Results: All formulations demonstrated significant variation (ANOVA p < 0.0001). However, parallelism testing failed comprehensively: overall F-test (p = 0.0094), χ²-test (p = 0.0001); male patients F-test (p < 0.0001), χ²-test (p = 0.0001); female patients F-test (p < 0.0001), χ²-test (p = 0.0001). Equivalence testing confirmed non-equivalence across all drugs versus standard for all 4PL parameters in both genders. Graphical analysis revealed inconsistent logarithmic dose spacing and variable horizontal shifts (Δ), violating parallelism assumptions. Conclusion: The consistent failure of parallelism testing across all analyses prevented relative potency estimation, indicating potential degradation of the reference standard, formulation inconsistencies, or assay design flaws. This underscores the critical importance of parallelism validation in bioassays and highlights methodological challenges in antimalarial potency assessment.