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

Table 1

The code and composition of hydrogels obtained using a full factorial method of experimental design. Three factors (solutions of Cht, PVP, and Gen) at two levels (low (L) and high (H) concentrations) were employed. Samples were polymerised at 50°C in an oven for 24 h and subsequently stored at 5°C in a fridge.

Gel code	Independent factors
	Cht		PVP		Gen		Average molar ratio
	Level	Volume (mL)	Level	Volume (mL)	Level	Volume (mL)	Cht : PVP : Gen
HHH	H	0.5	H	0.5	H	0.100	1 : 19 : 69
HHL	H	0.5	H	0.5	L	0.004	1 : 19 : 3
HLL	H	0.5	L	0.2	L	0.004	1 : 8 : 3
LLL	L	0.2	L	0.2	L	0.004	1 : 19 : 7
LLH	L	0.2	L	0.2	H	0.100	1 : 19 : 171
LHL	L	0.2	H	0.5	L	0.004	1 : 49 : 7
HLH	H	0.5	L	0.2	H	0.100	1 : 8 : 69
LHH	L	0.2	H	0.5	H	0.100	1 : 49 : 171

1.5% (w/v) Cht in an aqueous 1% (v/v) acetic acid solution; 5% (w/v) PVP aqueous solution; 0.5% (w/v) Gen aqueous solution.