The invention is related to a cost-effective method for producing water-soluble thermally-crosslinkable hydrophilic polymeric materials. Resultant materials can find particular use in preparing a packaging solution used for packaging and autoclaving medical devices, especially contact lenses. Those packaging solutions are especially suitable for forming a relatively-thick and soft hydrogel coatings on contact lenses or medical devices according to an in-package-crosslinking (IPC) processes. The resultant non-silicone hydrogel coatings can have a superior lubricity (a friction rating of 0) with minimized or no surface cracking.