Shi YQ, Yao J, Liu F, Hu CQ, Yuan J, Zhang QM, Jin SH. Establishment of an HPLC identification system for detection of counterfeit steroidal drugs. J Pharm Biomed Anal. 2008;46(4):663-9.

A set of simple HPLC methods employing UV detection were developed for detection of counterfeit drugs by the qualitative and quantitative analysis of nine steroidal drugs, ethinylestradiol, diethylstilbestrol, norethisterone, norgestrel, methyltestosterone, medroxyprogesterone acetate, progesterone, testosterone propionate and nilestriol. The methods were based on studies of the relationships between the retention factors (k) of the nine compounds and the percentages of water to methanol in the mobile phases on a reverse phase Alltima C(18) column giving reliable separation of the compounds under three sets of chromatographic conditions. The methods were validated using statistical tests and were used on nine commercial samples for detection of possible counterfeit drugs.