Bioavailability of theophylline from glutaraldehyde cross-linked casein microspheres in rabbits following oral administration

Theophylline-loaded bovine casein microspheres were prepared by the glutaraldehyde cross-linking of an aqueous alkaline dispersion of the protein containing the drug in a non-aqueous dispersion medium. The cross-linking of the protein droplets was carried out via the organic phase by the addition of varying quantities of glutaraldehyde- saturated toluene. In vitro release of the drug was examined in simulated gastric fluid at 37°C from spheres...