Montmorillonite as a pharmaceutical carrier: interaction with papaverine
Forni, F.; Iannuccelli, V.; Coppi, G.; Vadelli, M.A.; Cameroni, R.
Il Farmaco; Edizione Pratica 40(4): 101-110
1985
ISSN/ISBN: 0430-0912 PMID: 4007144 Document Number: 266907
In order to investigate the possible use of natural carriers for the controlled release of drugs, the effects of pH and of the concentration of the active principle on the loading of montmorillonite (Veegum) with papaverine hydrochloride was studied. The drug-clay interaction was achieved via ion exchange up to the total exchange capacity of the montmorillonite while greater quantities of papaverine can only be retained at alkaline pH values. X-ray diffractometry allowed identification of the site of interaction of the drug with Veegum in the interlayer between TOT sheets of montmorillonite where, as shown by IR-spectrophotometry and differential thermal analysis, papaverine is present as base. The mechanisms thought to lead to the formation of the papaverine-Veegum complex at different pH values are discussed and a structural model proposed.