Instrumental analysis and testing of counterfeit Viagra suspected to Essay

Instrumental analysis and testing of counterfeit Viagra suspected to contain amphetamine - Essay Example phRMA has requested China, Mexico, Indonesia, Lebanon and many countries in the Central America to have a close watch on the drugs used in their countries. They have also warned those countries that the illegal drugs were found to get originated from Czech Republic, Sweden and Switzerland. (Oslen et al., 2002).The Drug manufacturer take many necessary steps to prevent counterfeiting of the drugs but their efforts are getting veined off because of the different methods that they adopt in trade and their distribution systems are very complex for tracing off. The illegal drug manufacturers are very smart enough to steal the name, basic formula, holograms and are able to prepare the counterfeit drug very smartly as the real drug. This has become a head ache for all the drug manufacturers. The only possibility for them is to develop analytical methods that can easily identify the authentic and fake products through simple testing methods. Sildenafil Citrate is a drug that is used to treat the pulmonary arterial hypertension and erectile dysfunction. Its Brand Name is Viagra, developed and marketed by Pfizer.the chemical composition of Sildenafil citrate is 1-( [3- ( 6, 7- dihydromethyl -7- oxo -3- propyl -1H – pyrazolo [4,3 - d] pyrimidin – 5 – yl ) - 4- ethoxy – phenyl ] sulfonyl ])- 4 – methyl piperazine. Viagra is used as a novel oral medicine for penile erectile dysfunction, the inability to keep hard erect penis for satisfactory sexual intercourse. Sildenafil citrate inhibits the cyclic guanosine monophosphate- specific phosphodiesterase present at the penis and making the cGMP to get accumulated at the corpus cavemonsum. This pill when taken inside, starts its effect after the twenty minutes of inhalation and lasts up to three hals lifes ( 18 hours ). Viagra came in to the market by 1998 after the US Food and Drug Administration approved it. Viagra was recommended for Erectile dysfunction as the over the counter drug. By the year 2002, Viagra sales accounted for about 92% of the global market for the pill to treat erectile dysfunction. The safety of this medicine was established in many pre- and post- approval studies. Phosphodiesterase family type five classes.(PDE). The PDE - 5 class receptors are found in corpus cavernoscum, platelets, skeletal muscle, vascular and visceral muscles. Of these at penis there are larger amount of PDE-5 than any other region. PDE-5 breaks down cGMP which causes the contraction of the penile arteries and smooth muscles. As the chemical structure of sildenafil is similar to the cGMP, the binding of sildenafil inhibits the cGMP from binding to the PDE-5 through the competitive inhibition mechanism. (McCullough, 2002). Amphetamine is a phenlyethylamine class drug that acts as a psycho stimulant drug. This drug is generally used as a performance enhancer. Amphetamine is found to increase the energy level, wakefulness and they are able to make the body work even at appetite an d fatigue conditions. Because of these characteristics Amphetamine is chosen as a counterifeit drug for Viagra by the illegal drug manufacturers. In the counterfeit Viagra’s, Sildenafil was present at lower concentration and the other drugs such as amphetamine, methamphetamine and ring substituted analogs. A rapid screening technique is essential for the quick identification of the counterfeit drug from the real ones. Various