Method for incorporating active agents into a hydrophilic polymer foam

A process for manufacturing a hydrophilic polymer foam exhibiting a gradient of a water-soluble active agent, the process comprising:

• a) depositing an aqueous solution or dispersion comprising the water-soluble active agent on an impermeable nonporous support;
• b) pouring a precursor mixture of the foam, in a form of an aqueous dispersion comprising either monomers or prepolymers, over the aqueous solution or dispersion that has been deposited on the support at the end of step a) wherein the water-soluble active agent dissolves in the precursor mixture of the foam;
• c) polymerizing the precursor mixture in which the water-soluble active agent is dissolved in step b) to produce the hydrophilic polymer foam incorporating the water-soluble active agent;
• d) drying the hydrophilic polymer foam;
• and
• e) separating the impermeable nonporous support from the foam after the foam has been dried in step d),
• wherein 80%-90% of the total weight of the water-soluble active agent is found in the lower 33% of the total volume of the hydrophilic polymer foam, which is the volume of the foam closest to the impermeable nonporous support at the end of step d).

A process for manufacturing a hydrophilic polymer foam exhibiting a gradient of a water-soluble active agent, the process comprising:

• a) depositing an aqueous solution or dispersion comprising the water-soluble active agent on an impermeable nonporous support, and drying the support on which the aqueous dispersion or solution has been deposited to obtain a support that is coated with the water-soluble active agent;
• b) pouring a precursor mixture of the foam, in a form of an aqueous dispersion comprising either monomers or prepolymers, over the support that has been obtained at the end of step a), wherein the water-soluble active agent dissolves in the aqueous dispersion comprising the precursor mixture of the foam;
• c) polymerizing the precursor mixture in which the water-soluble active agent is dissolved in step b) to produce the hydrophilic polymer foam incorporating the water-soluble active agent;
• d) drying the hydrophilic polymer foam;
• and
• e) separating the impermeable nonporous support from the foam after the latter has been dried in step d),
• wherein 80%-90% of the total weight of the water-soluble active agent is found in the lower 33% of the total volume of the hydrophilic polymer foam, which is the volume of the foam closest to the impermeable nonporous support at the end of step d).