Method of purifying moxidectin through crystallization
AssigneeWyeth
InventorsIsidoro Sorokin, Paola Di Raimondo, Chin-Liang Chou
Life of this patent
Estimating the term…
Abstract
Methods for the purification of the macrolide moxidectin result in higher purity levels than can often otherwise be obtained. The crystalline moxidectin is then used in a wide variety of pharmaceutical and veterinary applications, including the prevention, treatment and control of parasites in plants, animals and humans.
Claims34
A method for purifying moxidectin, said method comprising:
- a) combining moxidectin with a first solvent to produce a moxidectin solution;
- b) concentrating said solution at a temperature at or below about 50° C., and thereafter cooling the temperature of said moxidectin solution to a temperature within the range of about 40° to 30° C.;
- c) combining a second solvent with said moxidectin solution;
- and thereafter
- d) agitating the moxidectin solution while lowering the temperature to within the range of about 30 to 10° C., so as to generate moxidectin crystals from said solution;
- e) filtering said crystals from said moxidectin solution;
- and
- f) drying said crystals.
A method to purify solid moxidectin, the method comprising:
- a) dissolving solid moxidectin in methylcyclohexane, (MCH), resulting in a moxidectin/MCH solution;
- b) concentrating said moxidectin/MCH solution at a pot temperature of about 45° C. to 50° C. under vacuum;
- c) adding n-heptane to the moxidectin/MCH solution, at a ratio of about 4:1 n-heptane to MCH, under agitation;
- d) aging the resultant solution for about 4-5 hours at about 30° C.;
- e) aging said solution at a temperature of about 10° C. for about 2-3 hours so as to generate moxidectin crystals;
- and
- f) filtering and drying said crystalline moxidectin under vacuum.
A process for generating moxidectin crystals from amorphous moxidectin, which comprises:
- a. adding amorphous moxidectin to a first solvent to produce a moxidectin solution;
- and thereafter
- b. causing the weight percentage of moxidectin within said solution to be within the range of about 40-44% at a temperature within the range of about 45-50° C. for said solution;
- c. cooling said solution and adding a second solvent to said moxidectin solution at a temperature within the range of about 30-35° C. for said solution;
- d. lowering the temperature of said solution to about 10° C. over the period of about 2-8 hours, while agitating said solution such that said agitation increases over said period so as to effect crystallization of said moxidectin;
- and
- e. drying said moxidectin crystals.
Moxidectin crystals which are at least about 94% pure.
Moxidectin crystals which are at least about 94-96% pure.
Moxidectin crystals which are at least about 96% pure.
Dependencies are inferred from the claim text.