Zilpaterol hydrochloride in specific crystallization state, its production, and intermediate substance used therefor

Abstract

Abstract PROBLEM TO BE SOLVED: To produce a compound useful as a breeding additive for animal effective for promoting the increase in body weight. SOLUTION: This anhydrous zilpaterol hydrochloride contains <5% of crystal having a size of ≥15μm and the remaining part of the crystal having a size of ≥250μm. The compound having the objective crystal morphology can be produced by preparing a supersaturated aqueous solution or a water/ethanol solution of zilpaterol hydrochloride at ≥50°C, cooling the solution to precipitate monohyrate crystal, lowering the temperature of the system to ≤20°C and drying the obtained trihydrate crystal. As an alternative, anhydrous zilpaterol hydrochloride is dissolved in water at ≤30°C to obtain a saturated aqueous solution of the hydrochloride and the solution is subjected to spontaneous recrystallization to obtain a trihydrate. The trihydrate is also producible by dissolving the hydrochloride in a minimum volume of hot water of 60-100°C, stirring the solution at 20°C and pouring into a saturated water/alcohol solution of the hydrochloride containing a seed trihydrate crystal added to the solution beforehand. COPYRIGHT: (C)1997,JPO

Inventors

• 👤 Yves Chevremont
• 👤 イブ・シェブルモン
• 👤 Jean-Yves Godard
• 👤 ジャンイブ・ゴダール

Bibliographic Details