Abstract: A method of loading a drug into a crosslinked polymer network and protecting the drug from the effects of inactivation is described. The method includes the steps of contacting a biologically active solute (e.g. drug) with: (i) a gel network; (ii) a loading polymer that is somewhat immiscible with the gel; and (iii) a salt, under conditions sufficient for the biologically active solute to selectively partition into the gel and the salt and the loading polymer to be entrained in the gel. A drug delivery system including a polymer gel network and the drug to be delivered is also described. The system also includes a salt and/or a loading polymer. The system protects the drug from loss of activity. In one embodiment, the polymer gel network is capable of expanding or collapsing in response to a change in an environmental condition to which the gel is exposed, the expanding or collapsing sufficient to release the drug into an environment of use.