Viagra - Sildenafil citrate

Pfizer also received a Crystal Faraday Award for optimizing the process used to manufacture the active ingredient in Viagra , sildenafil citrate. Shown in Figure 3.6 is the solvent usage during each stage of process development for sildenafil citrate over a 15-year lime line [19]. 

Jackson G, Gillies H, Osterloh I. Past, present and future a 7-year update of Viagra (sildenafil citrate). Int J Clin Pract 2005 59 680-691. 

Viagra (Sildenafil citrate). Pfizer Ltd. UK Summary of iM-oduct characteristics, June 2006. 

Viagra (sildenafil citrate) was introduced in 1998 as an effective way to treat male erectile dysfunction (MED). It was discovered accidentally during clinical trials of the compound as a treatment for coronary heart disease and works by enhancing the production of nitric oxide (NO) in erectile tissue, ultimately leading to vasodilation (see Real Life 26-1). The route by which Viagra was made originally in the research laboratory is shown below. 

The environment for intellectual property protection is still a concern in China. Pharmaceutical companies ve been alarmed by the 2004 legal decision to overturn the Chinese patent for Pfizer s Viagra (sildenafil citrate). This was followed by a case where GlaxoSmithKline stepped back from defending its patent in China for rosiglitazone, the active ingredient of its anti-diabetes drug Avandia. 

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