A packaged treatment composition comprising a polymerisable and/or curable composition comprising (1) a packaged first flowable component comprising a source of hydrogen peroxide and (2) a separately packaged second flowable component； the composition comprising a polymerisable monomer or oligomer, a polymer and/or a curing agent, the composition capable of forming a solid composition by polymerisation and/or curing following mixing of the first and second flowable components. The polymerisable monomer may be an AMPS monomer, forming an AMPS hydrogel upon polymerisation. The composition may be usable in treating onchomycosis, a fungal infection of the human nail.
