White crystalline solid or 18-hydrate form. Soluble in water, noncombustible, and nontoxic. Boiling point 214°F, melting point 3.9°F. Density 10.9 lb/gal
Bioavailability is the fraction of administered drug reaching systemic circulation. Intravenous administration has 100% bioavailability. Bioavailability is measured as ratio of extravascular to intravenous AUC. Bioavailability is an average value with ± deviation range
Clearance represents drug elimination efficiency as elimination rate divided by concentration. Usually measured in L/h or mL/min, different from excretion (mg/min). Concept described by Thomas Addis at Edinburgh Medical School
VD represents theoretical volume needed to contain drug at blood plasma concentration. VD indicates drug distribution in body tissue rather than plasma. Higher VD indicates greater tissue distribution
Prostaglandins are hormone-like lipid compounds found in almost every tissue. They are derived from arachidonic acid and contain 20 carbon atoms. Prostaglandins act as autocrine or paracrine factors with local target cells
Bioavailability measures active substance absorption from dosage forms to systemic circulation. Bioequivalence establishes equivalent performance between products containing same active substance. Essentially similar products must be bioequivalent unless safety/efficacy differs