Modification of permeant

A method of modifying a permeant comprising forming a liquid system consisting of a polymer-containing member selected from the group consisting of polyvinylpyrrolidone or a derivative thereof, a combination of polyvinylpyrrolidone or a derivate thereof and a plasticizer, and a combination of polyvinylpyrrolidone, a solvent and a plasticizer, reacting the polymer-containing member in the presence of the permeant for significantly increasing the effective molecular weight of the polymer therein under conditions which substantially preserve at least one useful permeant function of the permeant, continuing the reaction under such conditions to a sufficient extent for substantially reducing the diffusion rate, volatility, flammability, toxicity or susceptibility to oxidation or other form of environmental attack upon the permeant and recovering a reaction product having a consistency ranging from a liquid to a non-self-supporting soft gel, from which the permeant may escape for performing its permeant function in or on a host medium outside the reaction product.