Terazosin hydrochloride

Terazosin hydrochloride is a drug developed by Abbott Laboratories for the treatment of hypertension and benign prostatic hyperplasia, and marketed as the dihydrate under the trade name Hytrin since 1987. The patent of interest here is U.S. Patent No. 5,504,207 (the 207 patent), tiled in October, 1994 for which the fourth claim is a particular anhydrous crystalline form of terazosin hydrochloride, designated by Abbott as Form IV , a form not marketed by Abbott. In the 207 patent. Form IV is defined by reference to the X-ray powder diffraction pattern, listing the peak positions of several of the peaks. To be within the scope of claim 4 of the 207 patent, a product must be anhydrous terazosin hydrochloride and must exhibit a powder X-ray diffraction pattern having each of the principal peaks identified in claim 4. 

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Two district court decisions have examined the use of brand payment provisions in the settlement agreements involving Cardizem CD and Hytrin. Both courts have foimd the agreements to be per se restraints of trade imder Section 1 of the Sherman Antitmst Act. In re Cardizem CD Antitrust Litigation, 105 F.Supp.2d 618, 684 (E.D. Mich. 2000) and 105 F.Supp.2d 618, 622 (E.D. Mich. 2000) In re Terazosin Hydrochloride Antitrust Litigation, 164 F.Supp.2d 1340, 1342 (S.D. FI. 2000). 

Abbott Laboratories ( Abbott ) distributes terazosin hydrochloride (known by the brand name Hytrin), which is approved for the treatment of hypertension and symptomatic benign prostatic hyperplasia. The FDA approved the Hytrin tablet NDA on August 7, 1987, and the capsule NDA on December 14, 1994. Abbott sells the dihydrate form of terazosin hydrochloride (having two associated water molecules). ... 

AlPHAj-adrenergic blocking agents doxazosin mesylate prazosin hydrochloride terazosin hydrochloride dihydrate... 

Hytrin l ing Terazosin hydrochloride X X X X Iron Oxide X Vanillin... 

Teratolol hydrochloride Terazosin hydrochloride Terconazole Terfenadine... 

Terazosin (hydrochloride), 6,7-dimethoxy-2-[4-tetrahydrofuran-2-carbonyl)piper-azin-l-yl]-4-quinazolinamine, a-adrenoreceptor antagonist antihypertensive [63074-08-8],... 

Terazosin Hydrochloride. Terazosin hydrochloride. I -l4-amino-f).7-dimethoxy-2-quinaz.olinyl)-4-(tetnihydro-2-fu-royllpipcrazinc monohydrochloride (Hytrin), is a structural congener of prazosin hydrochloride. It possesses similar selc-ctive properties of specincally inhibiting 0 -udrenergic receptors. The drug is slightly less potent than prazosin hydrochloride. Terazosin hydrochloride has a half-life of approximately 12 hours, which is much longer than that of prazosin. This lends itself to a once-daily dose to control hypertension in ntany patients. 

Bauer, J. F., Krogh, S. K., Chang, Z. L. and Wong, C. F. Determination of minor impurities in terazosin hydrochloride by high-performance liquid chromatography. ]. Chromatogr. 648 175-181, 1993. 

Terazosin (hydrochloride), 6,7-dimethoxy-2-[4-tetrahydrofuran-2-carbonyl)piper-... 

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]. 

Molecular formula C19H25NSO4 Molecular weight 387.4 CAS Registry No. 65390-64-7 (terazosin), 70024-40-7 (terazosin hydrochloride dihydrate), 63074-08-8 (terazosin hydrochloride)... 

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