Method of preparing transdermal delivery system

A method for preparing a transdermal delivery system, comprising:

• (i) laminating a microporous membrane layer onto a top surface of a contact adhesive layer to form a contact adhesive laminate having a top surface and a bottom 3 surface;
• (ii) preparing a drug matrix layer comprising:
• forming a first mixture comprising triethyl citrate, lauryl lactate, and ethyl acetate,
• adding ascorbyl palmitate to the first mixture,
• adding polyvinylpyrrolidone to the first mixture,
• adding donepezil HCl polymorph Form III to the first mixture,
• adding sorbitan monolaurate to the first mixture,
• adding sodium bicarbonate and glycerin to the first mixture, wherein the sodium bicarbonate is present in a molar ratio of at least 0.85 to the donepezil HCl,
• adding an acrylate polymer to the first mixture,
• coating the first mixture on a release liner,
• drying the coated mixture, and
• removing the release liner, thereby preparing the drug matrix layer;
• (iii) laminating the drug matrix layer onto the top surface of the contact adhesive laminate to form a drug matrix laminate having a top surface and a bottom surface;
• (iv) laminating a separating layer onto the top surface of the drug matrix laminate to form an active laminate having a top surface and a bottom surface, wherein the separating layer comprises a top surface and a bottom surface, wherein the top surface of the separating layer comprises a coating of ethylene-vinyl acetate copolymer, and wherein the bottom surface of the separating layer is in contact with the top surface of the drug matrix laminate;
• (v) laminating a polyester fabric onto an adhesive overlay layer comprising acrylate polymer to form a backing layer having a top surface and a bottom surface;
• (vi) laminating the bottom surface of the backing layer onto the top surface of the active laminate so that the adhesive overlay layer is in contact with the top surface of the active laminate;
• (vii) treating the top surface of the separating layer with a corona discharge treatment to form a treated separating layer,
• wherein the corona discharge treatment is performed using a power of from 0.10 KW to 0.12 kW and a power density of from 2.1 to 2.6 W/ft2/min,
• wherein the treated separating layer comprises a top surface and a bottom surface such that the top surface of the treated separating layer has a surface energy of at least 40 Dynes, and
• wherein the bottom surface of the contact adhesive layer is in contact with a first process liner;
• (viii) removing the first process liner to expose the bottom surface of the contact adhesive layer;
• and
• (ix) laminating a release liner onto the bottom surface of the contact adhesive layer, thereby forming the transdermal delivery system.