Multifunctional transdermal dressing for wounds

A method of preparing a multifunctional polymer-free clay film comprising a clay, an antimicrobial agent, a zwitterion and an analgesic, the method comprising:

• a) mixing a clay, the antimicrobial agent and water to form a first slurry;
• b) centrifuging and washing the first slurry of step a) with water to obtain a washed second slurry;
• c) adding a zwitterion and water to the washed second slurry of step b) to obtain a third slurry;
• d) casting the third slurry of step c) onto a substrate to obtain a first dried product;
• e) adding drops of the analgesic in a non-aqueous solvent onto the first dried product of step d) to obtain a resultant product,
• f) drying the resultant product to obtain a second dried product;
• and,
• g) separating the second dried product of step f) from the substrate of step d), wherein the second dried product of steps f) and g) is the multifunctional polymer-free clay film which provides both antimicrobial and pain relieving properties, wherein the zwitterion is selected from the group consisting of N,N,N-trimethylglycine and N,N,N-trimethylglycine hydrochloride, and wherein the antimicrobial agent in the multifunctional polymer-free clay film is selected from the group consisting of silver ion, copper, silver-containing compounds, and, copper containing compounds.