Patent ID: 6534674
Filing Date: 2003-03-18
Classification: A61P,C01B,C07F

Abstract:
A process for the preparation of crystalline disodium pamidronate 3-4 hydrate having a water content of 17.0-20.0 wt % which has the following lattice spacings (d-values) and relative line intensities (intensities) of its X-ray powder pattern:d values (Angstrom)IntensityEvaluation11.7256.8Weak10.6303.1Weak7.842942.3Very strong6.781239.8Very strong5.86333.3Weak5.70401.4Medium5.321308.3Very strong5.23512.8Medium4.79231.0Weak4.69185.4Very weak4.60236.9Weak4.45124.9Very weak4.34295.9Weak4.15180.0Very weak4.08139.3Very weak4.00137.0Very weak3.91547.8Medium3.85483.4Medium3.66610.0Strong3.54180.4Very weak3.48291.3Weak3.38124.7Very weak3.22209.6Weak3.17198.1Weak3.11661.3Strong2.98446.2Medium2.96683.7Strong2.92566.9Strong2.91467.2Medium2.88771.1Strong2.84430.0Medium2.79317.0Weak2.76691.4Strong2.75640.6Strong2.70240.2Weak2.66268.2Weak2.60558.9Strong2.55218.1WeakEvaluation: very strong, strong, medium, very weak Evaluation: very strong, strong, medium, very weak comprising the steps of: neutralizing pamidronic acid with sodium methoxide or sodium ethoxide in absolute methanol or absolute ethanol at reflux to produce a salt; dissolving the resulting salt in water; filtering insoluble materials from the dissolved salt; allowing the resulting solution to stand at room temperature to form crystals; cooling the resulting crystalline solution slowly; filtering the cooled solution to obtain the crystals; and drying the resulting crystals at a temperature of 75-85Â° C. under normal pressure to obtain the crystalline disodium pamidronate 3-4 hydrate.