| abstract |
A pharmaceutical composition in the form of tablets or capsules provides a combination of temporal and spatial control of drug delivery to a patient to achieve effective therapeutic results. The pharmaceutical composition comprises a drug, a gas generating component, a dilating agent, a viscosifying agent and, optionally, a geleficant polymer. The dilating agent belongs to a class of compounds known as superdisintegrators (for example, cross-linked polyvinylpyrrolidone or sodium carboxymethyl cellulose). The viscosifying agent initially and then the gelling polymer form a hydrated gel matrix that traps the gas, causing the tablet or capsule to float so that it is retained in the stomach or in the upper part of the small intestine (spatial control). At the same time, the hydrated gel matrix forms a tortuous diffusion path for the drug, which results in a sustained release of the drug (temporary control). A preferred formulation of ciprofloxacin from a single daily administration comprises 69.9% of ciprofloxacin, 0.34% sodium alginate, 1.03% xanthic gum, 13.7% sodium bicarbonate, 12.1% cross-linked polyvinyl pyrrolidone and, optionally, other pharmaceutical excipients, the formulation being prepared in form of coated or uncoated tablet or capsule. |