Dear Waleed 

Their is one google groups of profeesional realted to medical field. They help to find out full asscess of most of the research or review article. Communicate your refernce list with them. Email ID is [email protected] . Please join this group.

Thank you

Roche or similiar diagnostic companies have the ready use kits for certain drugs. In clinical set-up, Therapoetic Drug Monitoring (TDM) is possible via using their kits and machines (such as TDX, IMX, CEDIA..). If the drug is not need to be monitorized in clinically, I think, the drug companies can help your research. Before the drug go to the market, its pharmacokinetics had been searched in detail by using serum and urine samples of volunteers. The drug should have "the code name" before called as a drug, you can get some analyses reports of them at pubmed, and I think you can see HPLC analyses and the other tecniques.

Thanks so much, i will try all trials

For pure substances:

http://www.sigmaaldrich.com

If you do the experiments, you must measure them yourself. Ask the company that produces the substance-drug.

I do not know if this will help, but see:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3580721/

Thanks so much Alex

following up on Buket Demireci's answer, you can look at the FDA website (name of active ingredient and "pharmacokinetics" or "clinical pharmacology"at http://www.fda.gov/Drugs/default.htm, may yield a lot of results, but the relevant ones should be fairly easy to spot). For drugs with a centralised EU marketing authorisation, see EMA'(www.EMA.europa.eu, then drug or ingredient name, then look for EPAR and scientific assessment  under "assessment history" for the relevant scientific report).