Pharmacokinetics intravascular administration

K Uno, T Aoki, R Ueno, I Maeda. Pharmacokinetics of nalidixic acid and sodium nifurstyrenate in cultured fish following bolus intravascular administration. Fish Pathol 31 191-196, 1996. 

Schultz, I., G. Orner, J. Merdink and A. Skillman. Dose-response relationships and pharmacokinetics of vitellogenin in rainbow trout after intravascular administration of 17/3-ethynylestradiol. / (/ /. Toxicol. 51 305-318, 2001. 

Lobster. Studies have been conducted to determine the pharmacokinetics of excretion, and the oral bioavailability of several drugs in adult lobsters of both sexes. Sulfadimethoxine and ormetoprim, which are used as a drug combination to treat various bacterial diseases, were studied separately and together. The usual dose ratio of the sulfadimethoxine ormetoprim combination is 42 4 mg/kg. Preliminary studies of the hemolymph concentration, and the tissue distribution at various times after intravascular and oral doses, were conducted with erythromycin, 50 mg/kg, in the free base form. Studies of the fate of phenol were conducted after intravascular administration of several doses. 

Figure 14.1 Structures of chlorpyrifos and some of its metabolites. (Modified from Barron, M.G., S.M. Plakas, and PC. Wilga. 1991. Chlorpyrifos pharmacokinetics and metabolism following intravascular and dietary administration in channel catfish. Toxicol. Appl. Pharmacol. 108 474-482.)...

This section will review how physiological factors at the site of injection impact the design of dosage forms and affect choice of excipients. First, pharmacokinetic factors affecting rates of delivery of drug to the blood will be considered. Then, biocompatibility or safety issues will be addressed. This analysis focuses on the intravascular (IV), IM, and SC routes of administration. 

Let us consider some drug administration practicalities. Up to now, the administered amounts were considered as initial units introduced simultaneously into several compartments at the beginning of the experiment. These amounts were considered as initial conditions to the differential equations describing the studied processes. Nevertheless, this concept seems to have limited applications in pharmacokinetics. In this section, we develop the probabilistic transfer and retention-time models associated with an extravascular or intravascular route of administration. 

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