Paxil - Paroxetine hydrochloride

Paxil (Paroxetine Hydrochloride) Drug Substance, Formulation, Method of use Drug Substance, Formulation, Method of Use 5 Beginning 17 months into the first stay 65 months Over l bilhon... 

C.F.R. 314.53(b). Examples of product-by-process patents are the three patents listed for Paxil (paroxetine hydrochloride). 

A number of additional examples of litigations involving crystal forms (e.g. terazosin hydrochloride, cefadroxyl, aspartame etc.) are described in Ref. [3b]. A more recent high profile case involved the Glaxo SmithKline antidepressant drug Paxil , paroxetine hydrochloride, which involved an anhydrate and a hemihydrate form of the API [44, 45]. 

The FDA approved Paxil in December 1992. Patent No. 4,007,196 (the 196 patent) covering the active ingredient paroxetine hydrochloride had expired prior to this date and, therefore, was not listed in the Orange Book. However, GSK listed Patent No. 4,721,723 (the 723 patent) whieh elaims paroxetine hydrochloride hemihydrate. (A hemihydrate is a form of the active ingredient that has one water molecule for every two paroxetine molecules incorporated into its crystalline structure.)... 

USAN Paroxetine Hydrochloride Trade Name Paxil GlaxoSmithKline Approval 1992 M.W. 327.39... 

The most widely known SSRIs are fluoxetine hydrochloride (4, Prozac , Lilly), sertraline hydrochloride (5, Zoloft , Pfizer) and paroxetine hydrochloride (6, Paxil , GSK). Fluoxetine (4, Prozac ) was the first SSRl approved and effected a revolutionary change in the treatment of depression. In 2000, it was the most widely prescribed antidepressant drug in the United States with worldwide sales of 2.58B. Sertraline (5, Zoloft ) has been available in the United States since 1992 and had worldwide sales of 2.14B in 2000. Compared to fluoxetine (4), it has a shorter duration of action and fewer CNS activating side-effects such as nervousness and anxiety. Paroxetine (6, Paxil ) generated worldwide sales of 2.35B in 2000 and has a relatively benign side-effect profile, which favors its use with elderly patients. 

Paxil , 40 mg (paroxetine hydrochloride). Front (top) and back views. 

GlaxoSmithKline. (2007, August). Paxil CR (paroxetine hydrochloride) controlled-release tablets. Prescribing Information. Retrieved from www.GSK.com... 

Paroxetine hydrochloride (CAS78246-49-8) Paxil (SmithKline-Beecham)... 

Other SSRIs include paroxetine hydrochloride (Paxil , Glaxo SmithK-line), fluoxamine maleate (Luvox , Abbott), sertraline hydrochloride (Zoloft , Pfizer), vilazodone hydrochloride (Viibryd , Eorest Laboratories), and citalopram hydrobromide (Celexa , Eorest Laboratories). 

Paroxetine is an antidepressant marketed by GlaxoSmithKline as Paxil. Example 2 of U.S. 4,007,196 (to A/S Eerrosan) describes preparation on the free base from of paroxetine, while U.S. 4,721,723 (to Beecham Group Pic.) describes the synthesis of the crystalline hydrochloride hemihydrate, which is the preferred form to administer the drug. What is the cost of production of the API in the crystalline hydrochloride hemihydrate form ... 

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