Genipin Cross-Linked Chitosan-Polyvinylpyrrolidone Hydrogels: Influence of Composition and Postsynthesis Treatment on pH Responsive Behaviour

Table 3

Visual observations of hydrogels. Samples were polymerised at 50°C for 24 h.

Gel code	Average molar ratio; Cht : PVP : Gen	Stability judged by the sample’s ability to retain the shape of the vial on extraction from the vial	Hydrogel colour
HHH	1 : 19 : 69	Stable	Very deep blue
HHL	1 : 19 : 3	Unstable	Light blue
HLL	1 : 8 : 3	Relatively stable	Light blue
LLL	1 : 19 : 7	Stable	Very deep blue
LLH	1 : 19 : 171	Stable	Very deep blue
LHL	1 : 49 : 7	Unstable	Light blue; (lightest shade)
HLH	1 : 8 : 69	Stable	Deep blue
LHH	1 : 49 : 171	Relatively stable	Light blue