Drug accumulation intravenous route

Drug accumulation (R), determined by different methods, for an intravenous bolus and extravascular route. 

Pharmacokinetics Slow intravenous infusion is employed for treatment of systemic infections or for prophylaxis. Because vancomycin is not absorbed after oral administration, this route is only employed for the treatment of antibiotic-induced colitis due to Q difficile. Inflammation allows penetration into the meninges. Metabolism is minimal 90-100 % is excreted by glomerular filtration. [Note Dosage must be adjusted in renal failure since the drug will accumulate. Normal half-life is 6-10 hours compared to over 200 hours in end-stage renal disease.]... 

Pharmacokinetics Administration can be by an intravenous, oral, or topical route. The efficacy of topical applications is doubtful. The drug distributes well throughout the body, including the cerebrospinal fluid. Acyclovir is partially metabolized to an inactive product. Excretion into the urine occurs both by glomerular filtration and tubular secretion. Acyclovir accumulates in patients with renal failure. 

Biodistribution of liposomes is a very important parameter from the clinical point of view. Liposomes can alter both the tissue distribution and the rate of clearance of the drug by making the drug take on the pharmacokinetic characteristics of the carrier (10, 11). The pharmacokinetic variables of the liposomes depend on the physiochemical characteristics of the liposomes, such as size, surface charge, membrane lipid packing, steric stabilization, dose, and route of administration. As with other microparticulate delivery systems, conventional liposomes are vulnerable to elimination from systemic circulation by the cells of the reticuloendothelial system (RES) (12). The primary sites of accumulation of conventional liposomes are the tumor, liver, and spleen compared with non-liposomal formulations (13). Many studies have shown that within the first 15-30 min after intravenous administration of liposomes between 50 and 80% of the dose is adsorbed by the cells of the RES, primarily by the Kupffer cells of the liver (14-16). 

Pharmacokinetics - labeling of a potential drug candidate. This study includes distribution studies of drug passage over the blood-brain barrier and selective accumulation in critical organs. Apart from intravenous administration, oral and nasal administration routes are other important applications employed for quantification of the deposition and disposition of a drug formulation. 

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