Effect of degree of cross-linking on swelling and on drug release of low viscous chitosan/poly(vinyl alcohol) hydrogels

Microwave‐Assisted Preparation of Hydrogel‐Forming Microneedle Arrays for Transdermal Drug Delivery Applications

“…When preparing hydrogels, the degree of crosslinking is a critical issue that directly affects different properties of the material, especially the swelling kinetics . This is a key aspect when hydrogels are prepared for drug delivery purposes . For this purpose infrared spectroscopy can be used to evaluate the crosslinking degree in Gantrez ® hydrogels.…”

Chitosan nanoparticle based delivery systems for sustainable agriculture

“…Agnihotri and Aminabhavi [165] also analyzed the dynamic swelling data of chitosan microparticles and concluded that with increase in cross-linking, swelling of chitosan microparticles decreases. Recently, Khan and Ranjha [193] studied the swelling behavior of chitosan/poly(vinyl alcohol) hydrogels as a function of pH, polymeric compositions and degree of cross-linking. They noticed that swelling increased by increasing poly(vinyl alcohol) contents in the structure of hydrogels at higher pH.…”

A rapid, non-invasive and non-destructive method for studying swelling behavior and microstructure variations of hydrogels

“…At pH 6.0, the osmotic pressure and electrostatic repulsion is weakened by the partial deprotonation of -NH3 + , which leads to lower swelling ratio. At pH 7.0 and pH 8.0, the loss of solvent (reduced swelling) results from a reduction of the osmotic pressure related to the counter-ions and the improved polymer-polymer interaction caused by the de-protonation of the -NH3 + groups (Khan & Ranjha, 2014;Wei, Fu, Zhang & Tang, 2015).…”

“…The protons forming the -NH3 + arise from the acidic environment. Then, the electrostatic repulsion between protonated amino groups (-NH3 + ) and the ionic osmotic pressure resulting from mobile counter ions surrounding the -NH3 + of the network resulted in water absorption of hydrogel(Khan & Ranjha, 2014; Martinez-Ruvalcaba, Sanchez-Diaz, Becerra, Cruz-Barba & Gonzalez-Alvarez, 2009). Besides,Fig.…”