Search

Thanks to multi-compartment systems it is possible to modify drug release. Two types of mini tablets containing 12.5 mg of ketoprofen were made: mini tablets of immediate (IR) and sustained (SR) release. Some of the tablets of immediate release were coated with an enteric coating, thereby obtaining a delayed release effect (IRc). For each tablet type, release profiles were tested in three media: 0.1 M HCl, phosphate buffer pH 4.5 and phosphate buffer pH 6.8. Based on the obtained results, three appropriate multi-compartment models have been constructed and tested. The factor limiting the amount of available ketoprofen at the absorption place is pH of the environment. It was observed that the increase in pH caused the increase of ketoprofen solubility. Constructed multi-compartment systems allowed to change the composition and the dose of medicinal substances easily. Thanks to this it is possible to adjust the release profile of the active substance to the individual patient, which meets the expectations of personalized medicine.

In the recent years a significant development of investigations with regard to bioavailability of ocular drugs has been noticed. The corneal epithelial barrier is the main pathway for ocular penetration of topically applied ophthalmic drugs into the anterior chamber. To work out an in vitro model of bovine corneal epithelial primary cultures and exercise it for permeability research with lipophilic and hydrophilic markers, permeability coefficients estimation of the 6-carboxyfluorescein and rhodamin B was made. The corneal epithelial cultures of the 3th or 4th passage were chosen for layered culture with inserts based on the liquid-liquid interface (for the first week) and the air-liquid interface (for the two following weeks). On the 7th, 12th, 18th, 21st experiment day TER values, and on the 21st day drug permeability coefficients, were determined. The mean TER values of the 7th, 12th, 18th, 21st day of corneal epithelial culture were: 122.14, 155.14, 198.43 and; 247.43 Wcm2, respectively. The mean values of permeability coefficients on the 21st day of culture for 6-carboxyfluorescein and rhodamin B were 3.87 +/-0.10 x 10(-6)cm/s and 3.65 +/- 0.06 x 10(-6)cm/s, respectively. We state that the in vitro bovine corneal epithelial primary culture model is useful for ocular studies.