The COVID-19 pandemic revealed profound weaknesses in global pharmaceutical supply chains, resulting in widespread shortages of critical medical supplies, delayed drug manufacturing, and disruptions in vaccine distribution. These supply chain vulnerabilities were exacerbated by several key factors, including an overreliance on a limited number of countries for active pharmaceutical ingredients (APIs), insufficient local manufacturing capacity, and logistical constraints in transportation and distribution networks. The pandemic also exposed inefficiencies in regulatory frameworks, leading to delays in approvals and limited agility in responding to rapidly changing demands. Furthermore, the lack of transparency and real-time monitoring across global supply chains hindered effective decision-making and coordination, aggravating the crisis. This paper provides an in-depth analysis of the critical factors that contributed to pharmaceutical supply chain disruptions during COVID-19, identifying missing links such as the need for diversification of supply sources, enhanced flexibility in manufacturing processes, and the integration of advanced technologies like artificial intelligence (AI), blockchain, and automation for supply chain optimization. The analysis highlights how supply chain visibility, digital innovation, and risk management strategies could improve resilience in the face of future global health crises. In addition to identifying these challenges, the paper proposes solutions to address the missing links in pharmaceutical supply chains, including the decentralization of production, the development of regional manufacturing hubs, and the creation of public-private partnerships to bolster local production. The role of government policies in facilitating faster regulatory approvals, fostering international cooperation, and incentivizing innovation is also explored. Case studies on successful post-COVID-19 adaptations, such as the rapid scale-up of vaccine production and the reconfiguration of personal protective equipment (PPE) supply chains, offer insights into effective strategies for building more resilient systems. Ultimately, this paper underscores the importance of a collaborative, multi-stakeholder approach to ensuring the stability and security of pharmaceutical supply chains. It calls for proactive measures to strengthen global supply chain infrastructures, improve regulatory agility, and embrace emerging technologies that can predict and respond to disruptions. These steps are crucial to safeguarding the continuous delivery of essential pharmaceuticals during future pandemics or other large-scale disruptions, ensuring global health security in an increasingly interconnected world.