The document discusses pulsatile drug delivery systems (PDDS), which aim to release drugs in a programmed pattern at appropriate times and sites. It describes different approaches to PDDS, including capsule-based systems using hydrogel plugs or osmotic pressure to control release, and coating-based systems using erodible layers or rupturable membranes. Key advantages of PDDS include adapting to circadian rhythms, avoiding first-pass metabolism, reducing dosage frequency, and improving compliance. The document also discusses factors that influence the performance of rupturable capsule-based PDDS and optimization of processing parameters.