Abstract - 595647 Disclosed is an implant material (such as a breast implant) comprising a biocompatible, water-insoluble, hydrophilic, flexible, elastic, cohesive aqueous polyvinylpyrrolidone (PVP) gel mass having a water-stabilised volume made by a process comprising: (a) combining a volume of water with an amount of polyvinylpyrrolidone (PVP) having an average molecular weight-related viscosity of K 29/32 or greater and wherein the weight of PVP is at least 65% of the weight of the water, and a minor amount (such as from about 0.1% to 1% of the weight of the PVP) of a base (such as sodium hydroxide) (b) reacting the mixture at ambient temperature and pressure until a cohesive water-insoluble gel mass is formed and (c) adding an amount of water to the reacted gel mass of (b) to maximize and stabilise the gel mass volume.
