Method for the production of crystalline forms and crystalline forms of optical enantiomers of modafinil
View Patent ↗The invention relates to a process for the preparation of crystalline forms of the optical enantiomers of modafinil, comprising stages comprising: i) dissolving one of the optical enantiomers of modafinil in a solvent other than ethanol, ii) crystallising the modafinil enantiomer, iii) recovering the crystalline form of the modafinil enantiomer so obtained. The invention also relates to a process for the preparation of the optical enantiomers of modafinil.
1. A laevorotatory enantiomer of modafinil in a polymorphic form that produces a powder X-ray diffraction spectrum comprising intensity peaks at the interplanar spacings: 8.54, 4.27, 4.02, 3.98 (Å).
2. The laevorotatory enantiomer of modafinil according to claim 1 , wherein the polymorphic form produces a powder X-ray diffraction spectrum further comprising intensity peaks at the interplanar spacings: 13.40, 6.34, 5.01, 4.68, 4.62, 4.44, 4.20, 4.15, 3.90, 3.80, 3.43 (Å).
3. A laevorotatory enantiomer of modafinil in a polymorphic form that produces a powder X-ray diffraction spectrum comprising reflections at 15.4, 31.1, 33.1 and 33.4 degrees 2θ.
4. The laevorotatory enantiomer of modafinil according to claim 3 , wherein the polymorphic form produces a powder X-ray diffraction spectrum further comprising reflections at 9.8, 20.8, 26.4, 28.3, 28.7, 29.9, 31.6, 32, 34.1, 35.1 and 39 degrees 2θ.
5. A pharmaceutical composition comprising a laevorotatory enantiomer of modafinil according to any one of claims 1 to 4 .
6. A pharmaceutical composition consisting essentially of a laevorotatory enantiomer of modafinil according to according to any one of claims 1 to 4 .
7. A Form I polymorph of (−)-modafinil.
8. A pharmaceutical composition comprising a Form I polymorph of (−)-modafinil according to claim 7 .
9. A pharmaceutical composition consisting essentially of a Form I polymorph of (−)-modafinil according to claim 7 .
10. A process for preparing a Form I polymorph of (−)-modafinil comprising the steps of:
(a) providing a solution of (−)-modafinil dissolved in a hot solvent;
(b) rapidly cooling the solution from step (a) to produce crystals;
(c) filtering the crystals;
(d) drying the crystals; and
(e) obtaining the crystals of said Form I polymorph of (−)-modafinil, wherein the solvent of step (a) is selected from water, methanol, absolute ethanol, absolute ethanol plus 3% water (v/v), and ethanol denatured with toluene plus 3% water, (v/v, based on the total volume of ethanol and toluene).