Keywords
Ornidazole
Stability
Climatic Zone IVb
Microclimate
Democratic Republic of the Congo
How to Cite
Abstract
Introduction
Pharmaceutical stability in tropical regions is a critical public health concern, as extreme heat and humidity can compromise drug integrity before the expiry date.
Purpose
This cross-sectional analytical study, incorporating experimental stability testing, aimed to evaluate the effects of architectural microclimates and hygrothermal conditions on the stability of the ofloxacin–ornidazole combination in the Democratic Republic of the Congo (DRC).
Methods
Observational field sampling (N = 30), combined with laboratory stability testing, was conducted in Kinshasa, Kisangani, and Bukavu. Laboratory stability was assessed using a validated spectrophotometric method.
Results
Drug content levels in Kinshasa pharmacies, characterized by uninsulated iron roofs, showed statistically significant underdosing (87.27% ± 1.45; p < .001; 95% CI [85.8, 88.7]) compared with the 98.40% ± 0.55 observed in temperate Bukavu (p < .001).
Conclusion
Building architecture and physical integrity (e.g., tablet crushing) are major determinants of drug quality in Climatic Zone IVb. The observed underdosing may compromise therapeutic efficacy and represents a recognized risk factor for accelerating antimicrobial resistance, as supported by global climatic models.
References
Busha, T. E., De Braekeleer, K., Tie, Y., Deconinck, E., Mitangala, N. P., Vandenberg, O., Coppieters, Y., Vermeulen, F., Harrison, C. M., & Byl, B. (2022). Contents of amoxicillin drugs dispensed in Goma, Democratic Republic of Congo. African Journal of Pharmaceutical Sciences, 2(1), 14–22. https://doi.org/10.51483/AFJPS.2.1.2022.14-22
Dahoumane, Z., Amara, M., Yaker, S., & Oukhelifa, N. (2021). Optimisation et validation d’une méthode de dosage simultané du paracétamol et de la caféine [Mémoire de fin d’études, Université Mouloud Mammeri]. https://dspace.ummto.dz/handle/ummto/13939
Garé, M., Chesnais, C. B., Campillo, J. T., Ngogang, M.-P., Fonkoua, M.-C., Le Moing, V., & Boullé, C. (2025). Antimicrobial resistance of Enterobacterales in Central Africa: A systematic review and meta-analysis. Communications Medicine, 5(1), 453. https://doi.org/10.1038/s43856-025-01148-3
International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. (2023). ICH guideline Q2(R2): Validation of analytical procedures. https://www.ich.org
Ive, K. D., Mankulu, K. J., Onoloke, A. O., Onya, L. G., Ndjibu, K. W., Mana, K. D., Ciza, H. P., Mbinze, K. J., & Mufusama Koy, S. J. P. (2025). Poor-quality medical products in the Democratic Republic of Congo: A ten-year retrospective study in Kinshasa (2012–2021). Orapuh Journal, 6(4), e1239. https://doi.org/10.4314/orapj.v6i4.39
Khuluza, F., Chiumia, F. K., Nyirongo, H. M., Kateka, C., Hosea, R. A., & Mkwate, W. (2023). Variations de température dans les installations de stockage pharmaceutique et connaissances, attitudes et pratiques du personnel concernant les conditions de stockage appropriées des médicaments dans le sud du Malawi. Frontiers in Public Health, 11, 1209903. https://doi.org/10.3389/fpubh.2023.1209903
Lunsevila, N. M., Ndondoboni, S. F. E., & Buya, A. B. (2023). Falsified drugs in the Democratic Republic of the Congo: Still a long way to go. Revue Congolaise des Sciences Humaines et Sociales (RECOSH), 2(2). https://recosh.cresh-rdc.org/
Patil, M. R., Ganorkar, S. B., Patil, A. S., Shirkhedkar, A. A., & Surana, S. J. (2021). Hydrotropic solubilization in pharmaceutical analysis: Origin, evolution, cumulative trend and precise applications. Critical Reviews in Analytical Chemistry, 51(3), 278–288. https://doi.org/10.1080/10408347.2020.1718484
Société Française des Sciences et Techniques Pharmaceutiques. (2007). Validation des méthodes de dosage bioanalytiques : Profil d’exactitude. STP Pharma Pratiques, 17(1), 1–88. https://www.sfstp.org
Suleman, S., Hasen, G., Melaku, T., Belew, S., Thitiri, J., Shangala, J., Obiero, C. W., Ngari, M., & Berkley, J. A. (2025). Effect of tropical climates on the quality of commonly used antibiotics: Protocol for a systematic review and meta-analysis. BMJ Open, 15(1), e090849. https://doi.org/10.1136/bmjopen-2024-090849
Yasmin, M. F., Hasan, M. R., & Hoque, M. (2026). Drugs’ stability in tropical climates: Formulation challenges, degradation pathways, and mitigation strategies. Mediterranean Journal of Pharmacy and Pharmaceutical Sciences, 6(1), 83–92. https://doi.org/10.5281/zenodo.18928651
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