Within regulated pharmaceutical environments, reliable records sit at the heart of product quality and patient safety. Every entry made during research, manufacturing, testing and distribution must be trustworthy enough to withstand scrutiny by inspectors, auditors, and downstream users. This review examines how the concept of data integrity has developed in the pharmaceutical sector, what frameworks now govern it, where companies still struggle, and where the next generation of digital tools may take it. The paper draws on regulatory documents from the FDA in the United States, the WHO at the global level, the EMA in Europe, the MHRA in the United Kingdom, India's CDSCO and the international PIC/S framework, together with published case studies and review literature. Documentation practice is traced from paper-based notebooks through early computerised systems, the 1997 introduction of 21 CFR Part 11, the WHO and MHRA guidance updates of 2016 and 2018, and the current era of cloud-based platforms and electronic batch records. The ALCOA principles, namely Attributable, Legible, Contemporaneous, Original, and Accurate, together with the four ALCOA+ extensions of Complete, Consistent, Enduring, and Available, are presented as the practical core of compliant documentation. Common failure modes are discussed, including human error, weak audit trails, unvalidated software, and governance gaps. The review closes by considering how artificial intelligence, blockchain ledgers, cloud platforms, and manufacturing automation may reshape pharmaceutical record-keeping in the years ahead. Robust documentation emerges as inseparable from product quality and public health.