RESUMO
Prediction of the drug level in the volume of distribution was made using a numerical model taking into account the following facts: the kinetics of drug release out of the dosage form along the gastrointestinal tract, the kinetics of absorption in the blood compartment and the kinetics of elimination. Various parameters intervene significantly for a given dosage form. Some emphasis was placed upon the rate of elimination of the drug which appears to be the main characteristic for the drug, especially when it is delivered through controlled release dosage forms. The rate of release of the drug out of the dosage form, as well as the dose frequency and the gastrointestinal transit time were also considered. The drug level in the plasma was expressed by the amount of drug as a fraction of the amount of drug initially located in the dosage form.
Assuntos
Preparações de Ação Retardada/farmacocinética , Área Sob a Curva , Aspirina/administração & dosagem , Aspirina/análogos & derivados , Aspirina/sangue , Aspirina/farmacocinética , Cimetidina/administração & dosagem , Cimetidina/sangue , Cimetidina/farmacocinética , Preparações de Ação Retardada/administração & dosagem , Esquema de Medicação , Trânsito Gastrointestinal , Lisina/administração & dosagem , Lisina/análogos & derivados , Lisina/sangue , Lisina/farmacocinética , Taxa de Depuração Metabólica , Modelos Biológicos , Estatística como Assunto , Tamoxifeno/administração & dosagem , Tamoxifeno/sangue , Tamoxifeno/farmacocinética , Teofilina/administração & dosagem , Teofilina/sangue , Teofilina/farmacocinéticaRESUMO
The concentration-time curve of ciprofloxacin has been assessed in the blood compartment and in the lung tissue following oral administration of the drug. Immediate release and erosion-controlled dosage forms have been examined. A numerical model based on finite differences and taking into account all relevant data has been built: the kinetics of drug release in the gastrointestinal tract, drug absorption in the blood compartment and elimination, and the transient diffusion of the drug through the lung tissue. A partition coefficient for the drug at the tissue-blood interface has been considered to express the drug concentration at the tissue surface. The effect of dose frequency and erosion rate on the antibiotic versus time curves in the plasma and the lung tissue has been studied in detail.