Details for Patent: 8,481,526
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Title: | Fluoroquinolone carboxylic acid molecular crystals |
Abstract: | Disclosed herein is a molecular crystal form of the compound (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8-- chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid. The molecular crystal is characterized by at least one of: (a) an X-ray powder diffraction ("XRPD") spectrum that comprises peaks at 2.theta. angles of 10.6, 15, 19.7, 21.1, and 22.degree..+-.0.2.degree.; (b) a DSC melting peak at 288.degree. C.; (c) a .sup.13C NMR spectrum having peaks at 23.3, 27.7, 41.1, 54.5, 116.6, and 153.5 ppm; and (d) pKa values of 5.65 and 9.91. The compound belongs to the class of fluoroquinolones and is useful as an antibacterial agent. |
Inventor(s): | King, Jr.; Harry M. (Webster, NY) |
Assignee: | Bausch & Lomb Incorporated (Rochester, NY) |
Filing Date: | Mar 12, 2010 |
Application Number: | 12/723,047 |
Claims: | 1. A molecular crystal form of (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8-- chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid characterized by an X-ray powder diffraction ("XRPD") spectrum that comprises peaks at 2.theta. angles of 10.6, 15, 19.7, 21.1, and 22.degree..+-.0.2.degree.. 2. A molecular crystal form of (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8-- chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid characterized by a differential scanning calorimetry ("DSC") melting peak at 288.degree. C. 3. A molecular crystal form of (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8-- chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid characterized by .sup.13C NMR spectrum having peaks at 23.3, 27.7, 41.1, 54.5, 116.6, and 153.5 ppm. 4. A molecular crystal form of (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8-- chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid characterized by pKa values of 5.65 and 9.91. 5. A molecular crystal form of (R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8-- chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid characterized by an X-ray powder diffraction ("XRPD") spectrum that comprises peaks at 2.theta. angles of 10.6, 15, 19.7, 21.1, and 22.degree..+-.0.2.degree.; a DSC melting peak at 288.degree. C.; a .sup.13C NMR spectrum having peaks at 23.3, 27.7, 41.1, 54.5, 116.6, and 153.5 ppm; and by pKa values of 5.65 and 9.91. 6. A method of making a molecular crystal of besifloxacin ((R)-(+)-7-(3-amino-2,3,4,5,6,7-hexahydro-1H-azepin-1-yl)-1-cyclopropyl-8- -chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid), comprising: (a) solubilizing a desired amount of a soluble salt of besifloxacin in a solvent (such as water) to form a solution; (b) adjusting the pH of the solution to a value in the range from about 6.2 to about 6.8; and (c) allowing a time sufficient to form the molecular crystal of besifloxacin. 7. The method of claim 6, further comprising recovering the molecular crystal of besifloxacin. 8. The method of claim 7, further comprising subjecting the recovered molecular crystal to a step of size reduction to nanometer- or micrometer-sized particles. |