Abstract: Six different pharmaceutical excipients, partially neutralised sodium polyacrylate, were used to prepare hydrogels with aluminium glycolate, and the cross-linking reaction was investigated by rheological means. The dynamic rheological parameters of hydrogel cross-linking were studied over a period of 60 d and the effects of molecular weight, degree of neutrality and pH values of partially neutralised sodium polyacrylate on the cross-linking process of the gels were discussed in detail. The results showed that the cross-linking reaction of the hydrogel system could be divided into three distinct phases: a fast reaction phase, a slow reaction phase and a termination phase. Non-linear least squares fitting of the kinetic curves of the partially neutralised sodium polyacrylate/Al³⁺ cross-linking reaction showed that the slow reaction phase was better fitted by the Exp Assoc model, while the fast reaction phase was better fitted by the linear model. When comparing the effects of the six partially neutralised sodium polyacrylates on the hydrogel properties, it was found that the higher the molecular weight of the sodium polyacrylate, the higher the modulus of elasticity of the hydrogels. Conversely, a lower degree of neutrality resulted in shorter gel formation times. In addition, the reaction rate of hydrogels prepared from partially neutralised sodium polyacrylates increased with higher pH values at the same degree of neutrality.