A pharmaceutical composition in the form of tablets or capsules provides a combination
of temporal and spatial control of drug delivery to a patient for effective therapeutic
results. The pharmaceutical composition comprises a drug, a gas generating component,
a swelling agent, a viscolyzing agent, and optionally a gel forming polymer. The
swelling agent belongs to a class of compounds known as superdisintegrants (e.g.,
cross-linked polyvinylpyrrolidone or sodium carboxymethylcellulose). The viscolyzing
agent initially and the gel forming polymer thereafter form a hydrated gel matrix
which entraps the gas, causing the tablet or capsule to be retained in the stomach
or upper part of the small intestine (spatial control). At the same time, the hydrated
gel matrix creates a tortuous diffusion path for the drug resulting in sustained
release of the drug (temporal control). A preferred once daily ciprofloxacin formulation
comprises 69.9% profloxacin base, 0.34% sodium alginate, 1.103% xanthan gum, 13.7%
sodium bicarbonate, 12.1% cross-linked polyvinylpyrrolidone, and optionally other
pharmaceutical xcipients, the formulation being in the form of a coated or uncoated
tablet or capsule.