摘要：

A unit dosage form of capsule, tablet or the like is composed of a large number of pellets made up of two or more populations of pellets or particles. Each pellet contains a core containing the therapeutic drug and a water soluble osmotic agent. A water-permeable, water-insoluble polymer film encloses each core. Incorporated into the polymer film is a hydrophobic, water insoluble agent which alters the permeability of the polymer film. The film coating of each population of pellets differs from the coating of every other population of pellets in the dosage form in the rate at which water passes through to the core and the rate at which drug diffuses out of the core. The osmotic agent dissolves in the water, causing the pellet to swell and regulating the rate of diffusion of drug into the environment of use. As each population of pellets releases its drug into the environment sequentially, the effect is to provide a series of pulsatile administrations of the drug from a single dosage form.

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