en
Scientific article
Open access
English

pH-sensitive hydrogels for site-specific drug delivery. II: Drug release behaviour from crosslinked alkyl acrylates/methacrylic acid copolymers

Published inSTP pharma sciences, vol. 9, no. 4, p. 341-349
Publication date1999
Abstract

Hydrogels sensitive to pH, intended for site-specific drug delivery, were prepared from the non-ionic hydrophobic monomers methyl or ethyl acrylate with methacrylic acid using various monomer ratios and with ethylene glycol dimethacrylate as a crosslinking agent. The networks were loaded with two model drugs, betamethasone and proxyphylline, which have very different solubilities. No significant drug release was observed in acidic media, and release only started at pH 5.5 for the poly(methyl acrylate-co-methacrylic acid) and at pH 6.5 for the poly(ethyl acrylate-co-methacrylic acid) hydrogels. The drug release mechanism was non-Fickian (anomalous), as analysed by the Peppas power function and bath the swelling inteiface and Deborah numbers. Release was thus partially controlled by the ionization-limited swelling of the network. ln practice, release rate was almost constant over the period of time tested and interestingly, it was not significantly affected either by drug solubility or by drug loading. Release could be modulated by varying the crosslinking ratio as well as the monomer ratio. The release durations appear very compatible with the long transit time of the colon. ln particular, the pH threshold for release of the poly(ethyl acrylate-co-methacrylic acid) hydrogels makes them very promising for such site-specific administration.

engfre
Keywords
  • pH-sensitive hydrogels
  • Site-specific delivery
  • Colonie delivery
  • Acrylic polymers
  • Crosslinkedpolymers
  • Drug release
  • Non-fickian diffusion
  • Anomalous transport
  • Hydrogels sensibles au pH
  • Libération spécifique au site
  • Libération au niveau du côlon
  • Diffusion non-fickienne
  • Transport anormal
Citation (ISO format)
RANJHA, Nazar Mohammad, DOELKER, Eric. pH-sensitive hydrogels for site-specific drug delivery. II: Drug release behaviour from crosslinked alkyl acrylates/methacrylic acid copolymers. In: STP pharma sciences, 1999, vol. 9, n° 4, p. 341–349.
Main files (1)
Article (Published version)
accessLevelPublic
Identifiers
  • PID : unige:175951
ISSN of the journal1157-1489
10views
1downloads

Technical informations

Creation03/11/2024 11:04:25 AM
First validation03/26/2024 2:53:54 PM
Update time03/26/2024 2:53:54 PM
Status update03/26/2024 2:53:54 PM
Last indexation03/26/2024 2:54:15 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack