Drug test Drug test A drug test is a technical analysis of a biological specimen, for example urine, hair, blood, breath, sweat, and/or oral fluid/saliva — to determine the presence or absence of specified parent drugs or their metabolites. Major applications of drug testing include detection of the presence of performance enhancing steroids in sport, employers and parole/probation officers screening for drugs prohibited by law (such as cannabis, cocaine, methamphetamine, and heroin) and police officers testing for the presence and concentration of alcohol (ethanol) in the blood commonly referred to as BAC (blood alcohol content). BAC tests are typically administered via a
Nanoparticles for drug delivery to the brain the drug-loaded nanoparticle to circulate throughout the body for prolonged periods of time. Further, the "stealth effect", caused in part by the hydrophilic and flexible properties of the PEG chains, facilitates an increase in localizing the drug at target sites in tissues and organs. A mechanism for liposome transport across the BBB is lipid-mediated free diffusion, a type of facilitated diffusion, or lipid-mediated endocytosis. There exist many lipoprotein receptors which bind lipoproteins to form complexes that in turn transport the liposome nano-delivery system across the BBB. Apolipoprotein E (apoE) is a protein that facilitates transport of lipids and cholesterol. ApoE