Table II.
Characterization of Salt Forms of Prazosin
| Compound | Melting point (onset °C) | TGA (% weight loss) | Karl Fischer (% water) | Mass spectrometry (M+ + 1)a | Residual solventb | Elemental analysisc | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| C | H | N | S | O | ||||||
| PRB | 264 | 0.2 (anhydrous) | 0.6 | 384.4 | Not detected | 59.5 (59.4) | 5.5 (5.5) | 18.3 (19.4) | – | 16.7 (15.8) |
| PRB HCl A | 284 | 0.2 (anhydrous) | 0.4 | 384.4 | Not detected | 54.3 (54.3) | 5.2 (5.3) | 16.7 (17.8) | – | 15.2 (14.1) |
| PRB HCl P | 272 | 12.3 (hydrate) | 13.6 | 384.4 | Not detected | 49.2 (49.5) | 5.8 (6.0) | 15.1 (15.7) | – | 22.1 (21.5) |
| PRB BSA | 316 | 4.2 (hydrate) | 5.5 | 384.4 | Not detected | 53.6 (52.6) | 5.2 (5.0) | 12.5 (13.2) | 5.7 (5.5) | 22.9 (23.7) |
| PRB CSA | 332 | 0.2 (anhydrous) | 0.6 | 384.4 | Not detected | 56.5 (56.3) | 6.0 (6.1) | 11.4 (12.1) | 5.2 (5.4) | 20.8 (20.0) |
| PRB MEA | 237 | 4.3 (hydrate) | 5.2 | 384.4 | Not detected | 51.6 (53.3) | 5.4 (5.2) | 13.1 (13.5) | – | 29.9 (28.0) |
| PRB MES | 267 | 5.0 (hydrate) | 5.2 | 384.4 | Not detected | 48.3 (47.2) | 5.4 (5.3) | 14.1 (14.8) | 6.4 (6.3) | 25.7 (26.4) |
| PRB OA | 254 | 7.4 (hydrate) | 8.3 | 384.4 | Not detected | 49.5 (47.3) | 5.3 (5.4) | 13.7 (12.9) | – | 31.4 (34.5) |
| PRB TSA | 300 | 3.6 (hydrate) | 4.2 | 384.4 | Not detected | 52.8 (53.4) | 5.6 (5.5) | 11.8 (12.8) | 5.4 (5.3) | 24.3 (23.0) |
aAtmospheric pressure chemical ionization mode of mass spectrometry analysis
bResidual solvent analysis by head space gas chromatography
cExpected (observed) for elemental analysis. Stoichiometry of salts was 1:1, as determined by elemental and high-performance liquid chromatography analysis