1 Pharmaceutical Design and Drug Delivery, Department of Pharmacy, Faculty of Health and Medical Sciences, Københavns Universitet2 Department of Anthropology, Study Council, Department of Anthropology, Faculty of Social Sciences, Københavns Universitet3 DissoFX, 25 Cooper Street, Machias, ME 04654, USA. Electronic address: firstname.lastname@example.org Pharmaceutical Design and Drug Delivery, Department of Pharmacy, Faculty of Health and Medical Sciences, Københavns Universitet5 Department of Anthropology, Study Council, Department of Anthropology, Faculty of Social Sciences, Københavns Universitet
Variable dissolution from sodium salts of drugs containing a carboxylic acid group after passing the acidic environment of the stomach may affect oral bioavailability. The aim of the present proof of concept study was to investigate pH effects in relation to the dissolution of sodium naproxenate in 0.01M hydrochloric acid. For this purpose a UV/vis imaging-based approach capable of measuring microenvironmental pH in the vicinity of the solid drug compact as well as monitoring drug dissolution was developed. Using a pH indicating dye real-time spatially resolved measurement of pH was achieved. Sodium naproxenate, can significantly alter the local pH of the dissolution medium, is eventually neutralized and precipitates as the acidic species naproxen. The developed approach is considered useful for detailed studies of pH dependent dissolution phenomena in dissolution testing.
Journal of Pharmaceutical and Biomedical Analysis, 2014, Vol 100, p. 290-293