[Cross-linking mechanism of the matrix of hydrogel patch].
In this study, we prepared various matrices of hydrogel patches and studied their cross-linking mechanism by observing their rheological properties, which could provide theoretical basis and deep technical support for further industrial development of hydrogel patch. Rheology method was used to do the amplitude scanning and single-frequency scanning for various hydrogel matrix, under the condition of oscillation mode of the rheometer. Then the linear viscoelastic region, composite modulus value, as well as changes in slope with time of the composite modulus and phase angle of various hydrogel matrix were analyzed in detail. The results showed that the stability of matrix was mainly determined by hydrogel frame; only in acidic environment, the cross-linking reaction between cross-linker and hydrogel frame can occur; elasticity of matrix can be decreased by organic acid and the effect level was related to the ratio of the number of carboxyl and hydroxyl (-COO(-)/-OH) in adjusters: if the ratio was not equal, the higher -COO(-)/-OH in adjusters would be the less elasticity of matrix decreased; the cross-linking speed of matrix was determined by adjuster, the cross-linking speed of matrix contain different adjusters was ranged in following order: matrix containing tartaric acid > matrix containing lactic acid > matrix containing malic acid > matrix containing citric acid; the cross-linking speed of matrix was not uniform in the whole cross-linking process.
Department of Pharmaceutics, Changhai Hospital, Second Military Medical University Shanghai 200433, China.
Xue-Mei
XM
Hou
Bao-Yue
BY
Ding
Zhen
Z
Cai
Wei
W
Zhang
Jing
J
Gao
Xue-Ying
XY
Ding
Wei-Hua
WH
Li
Shen
S
Gao
D019343:Citric Acid / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D008293:Malates / Q000737:chemistry; D012212:Rheology; D013644:Tartrates / Q000737:chemistry; D014783:Viscosity
D003432:Cross-Linking Reagents; D020100:Hydrogels; D008293:Malates; D013644:Tartrates; D019343:Citric Acid; D019344:Lactic Acid; C030298:malic acid; C029768:tartaric acid