Optimization techniques for the design and development of novel drug delivery systems, Part II

Optimization techniques are being explored extensively in pharmaceutical research as a tool to achieve the optimum composition of a delivery system. The design and development of novel drug delivery systems involve careful selection and optimization of several formulation- and process-related variables. Drug delivery from modified-release systems is usually affected by inherent gastrointestinal tract variables such as pH, gastric motility, and contents. Floating drug delivery systems have been pursued extensively as a promising approach to increase the gastric residence time of peroral controlled-release systems. These systems consist of buoyant polymers that are retained in the stomach for an extended period of time to provide continuous release of an incorporated drug. Designing a peroral drug delivery system that is capable of delivering drugs in a pulsatile or timed-release fashion requires delivery methods such as multilayered tablets and coated pellets. Colonic drug delivery is gaining interest as one of the important targeted drug delivery systems.