Sustainable pharmaceutical supply chain for humanitarian relief logistics

This study presents a novel framework for designing a sustainable pharmaceutical supply chain tailored for humanitarian relief logistics, leveraging blockchain technology to enhance transparency, traceability, and security. The proposed multi-layered network includes material suppliers, pharmaceutical plants, central warehouses, distribution points, hospitals, donation centers, disposal and recycling facilities, and secondary markets for recovered materials. Expired medicines are managed through safe disposal and recycling, promoting circular economy principles and reducing pharmaceutical waste. A multi-objective stochastic mixed-integer programming model is developed to simultaneously minimize total cost, minimize pollution emissions, and maximize social impact through job creation, considering pre- and post-disaster stages, multiple products, transportation modes, capacity limits, and demand uncertainty. The augmented ε-constraint and weighted sum methods are employed to generate Pareto-optimal solutions. The results reveal clear sustainability trends: as the weight of social objectives increases, total costs slightly rise while pollution levels decline and employment opportunities expand; conversely, prioritizing cost minimization reduces emissions benefits and social gains. The integration of blockchain technology further strengthens these trade-offs by enhancing coordination efficiency, transparency, and traceability. The proposed model demonstrates how blockchain-based sustainable strategies can balance economic, environmental, and social objectives in humanitarian pharmaceutical logistics, directly supporting multiple UN Sustainable Development Goals (SDGs).