Oral patch for treating mouth ulcers

A bilayer oral patch, comprising:

• (a) a drug layer comprising 3%-20% by weight (w/w) of amorphous tetracaine or a pharmaceutically acceptable salt thereof, 0.1%-2.0% w/w of amorphous triamcinolone or a pharmaceutically acceptable salt thereof, 20-90% w/w of a first film-forming material, 1-12% w/w of an adhesive, and 1-20% w/w of a cooling excipient;
• and
• (b) a backing layer comprising 70-95% by weight of a second film-forming material and 2-10% by weight of a plasticizer, wherein the backing layer prevents the tetracaine, the triamcinolone, or their pharmaceutically acceptable salts, from diffusing into the oral cavity;
• wherein the first film-forming material comprises (a) hypromellose acetate succinate (HPMCAS) and povidone (PVP), (b) ethyl cellulose and PVP, (c) HPMCAS and polyethylene glycol (PEG), or (d) HPMCAS and hydroxypropyl cellulose (HPC);
• the adhesive is selected from the group consisting of:
• polyacrylic acid, sodium alginate, copolymer of ethyl acrylate methyl methacrylate, guar gum, sodium carboxyl methyl cellulose, 5-methyl pyrrolidone chitosan, polyglutamic acid, polycarbophil, dextran sulfate, and any combination thereof;
• the cooling excipient is selected from the group consisting of:
• camphor, menthol, mint oil, clove oil, menthyl acetate, xylitol, sorbitol, thymol, and any combination thereof;
• and
• the second film-forming material is selected from the group consisting of:
• HPMC, HPC, hydroxyethyl cellulose (HEC), hydroxypropylated high amylose starch, methylmethacrylate-based copolymer, povidone, collagen, gelatin, pectin, cellulose acetate phthalate (CAP), polyvinyl alcohol (PVA), polyvinyl alcohol phthalate (PVAP), and any combination thereof.