PowerPoint Presentation

Q.1)Give characteristics of an active transport mechanism..

Q.2) What is enterohepatic cycling of a drug?. Enterohepatic cycling of the drug is the drug pathway between liver and intestine. It continued until the whole drug is metabolized or excreted from the body. The drug which is excreted in the intestine via bile are not reabsorbed and excreted through feces. Oral administration Fecal excretion BILE Metabolites Urinary excretion SMALL INTESTINE Biliary and/or conjugates excretion ENTEROHEPATIC CIRCULATION OF DRUGS Distributior to tissues LIVER Hydrolysis of conjugate and absorption BLOOD.

Q.3) List factors affecting protein binding of drugs..

Q.4) Give benefits of drug clearance.. i ) Clearance applies to all elimination rate processes, regardless of the mechanism for elimination. In addition, for first-order elimination processes, clearance is a constant, whereas the rate of drug elimination is not constant. It describes the relationship between plasma drug concentration and the rate of drug elimination.

Q.5) Comment on particle size as a tool to enhance bioavailability of drugs..

2. Nanosusoension : Nanosuspensions are sub-micron colloidal dispersion of pure particles of the drug, which are stabilized by surfactants. Nanosuspension technology is used for efficient delivery of The particle size distribution of the hydrophobic drugs solid particles in nanosuspensions is usually less than one micron with an average particle size ranging between 200 and 600 nm. Advantage : Increased dissolution rate due to larger surface area exposed. Eg., Nanosuspension approach has been employed drugs like paclitaxel, tarazepide, amphotericin B which are still on research stage..