Precipitation of calcium gluceptate from aqueous solutions
Suryanarayanan, R; Mitchell, AG
| HERO ID | 4837150 |
|---|---|
| In Press | No |
| Year | 1984 |
| Title | Precipitation of calcium gluceptate from aqueous solutions |
| Authors | Suryanarayanan, R; Mitchell, AG |
| Journal | Journal of Pharmaceutical Sciences |
| Volume | 73 |
| Issue | 1 |
| Page Numbers | 78-82 |
| Abstract | A precipitate encountered in solutions of calcium gluceptate was identified as hydrated calcium gluceptate. Precipitation was associated with a change from a very soluble amorphous anhydrous form to a sparingly soluble crystalline hydrate, the presence of seed crystals inducing crystallization, and unsuitable proportions of the alpha- and beta-epimers of calcium gluceptate. Various commercial samples and the corresponding precipitates were examined by elemental analysis, thermal analysis, X-ray diffraction, IR spectroscopy, and GC-MS. The proportion of the alpha- and beta-epimers in commercial samples was quantitated by GC. In this method, an aqueous solution of calcium gluceptate was converted into a mixture of glucoheptonic acids and their corresponding lactones by passage through a cation-exchange resin. The solution was freeze-dried, the acid-lactone mixture converted to the gamma-lactones using concentrated hydrochloric acid, and the resulting material trimethylsilylated with trimethylsilylimidazole. Stability studies of solutions prepared from calcium gluceptate obtained from various commercial sources indicate that above approximately 50% alpha-epimer, stability decreased with an increase in the relative proportion of the alpha-epimer. Material complying with USP specifications (pure alpha-epimer) is the least stable in solution. It is suggested that calcium gluceptate containing approximately equal proportions of the alpha- and beta-epimers be introduced in the USP monograph together with a method for estimating the proportions of the epimers. |
| Doi | 10.1002/jps.2600730121 |
| Pmid | 6694089 |
| Wosid | WOS:A1984SA06500020 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |