abstract

The goal of controlled-release oral dosage forms is to regulate the rate of drug release for a prolonged amount of time. This leads to fewer doses, less variation in plasma drug concentration, better patient compliance, and long-term therapeutic efficacy. However, because drug-release behaviour depends on numerous interdependent formulation and process variables, developing such dosage forms is difficult. Conventional trial-and-error techniques might need a lot of testing and might not be sufficient to find interactions between significant factors. A methodical, science-based approach to pharmaceutical development, Quality by Design (QbD) entails defining the Quality Target Product Profile (QTPP), identifying Critical Quality Attributes (CQAs), determining Critical Material Attributes (CMAs) and Critical Process Parameters (CPPs), assessing quality risk, applying Design of Experiments (DoE), creating a design space, and creating a suitable control strategy. The present study examines and proposes a methodical strategy based on QbD for the creation and improvement of oral dosage forms with controlled release. To evaluate the impact of formulation and process parameters on drug-release behaviour, published research on matrix tablets, osmotic systems, multilayer tablets, and polymeric controlled-release systems was examined. Polymer concentration, polymer viscosity, drug loading, compression force, coating factors, dissolving behaviour, and release kinetics are all given particular consideration. Research gaps on formulation-process integration, mechanistic comprehension, in vitro–in vivo correlation, artificial intelligence, continuous manufacturing, and patient-centric formulation design are also identified by the review. QbD-based development can lessen reliance on empirical experimentation while increasing formulation robustness, product understanding, manufacturing uniformity, and lifecycle management.