These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Solid-state esterification of codeine phosphate by the acid constituent of effervescent tablets.
    Author: Silver B, Sundholm EG.
    Journal: J Pharm Sci; 1987 Jan; 76(1):53-5. PubMed ID: 3585724.
    Abstract:
    Codeine phosphate in a paracetamol:codeine effervescent tablet was found to react at room temperature and 37 degrees C with the citric acid constituent to form citrate esters of codeine. The esterification was confirmed in a solid-state reaction at elevated temperature. The structures of the three possible monosubstituted esters (1-3) were elucidated from spectroscopic data (nuclear magnetic resonance and mass spectrometry) and by selective hydrolysis of the dimethyl esters to give symmetrical and asymmetrical dimethyl citrates. In the degradation reaction, formation of the symmetrically substituted citrate ester of codeine, 1, was found to predominate. Tartaric acid, which can be used in effervescent tablet formulations, was also found to give an ester with codeine phosphate in a similar nonsolvolytic reaction. A liquid chromatographic method was developed for the separation of the citrate esters of codeine.
    [Abstract] [Full Text] [Related] [New Search]