Process of Insulin Microneedle Patch Preparation:
Add an appropriate amount of polyvinyl alcohol powder to a certain amount of deionized water while stirring in a water bath heated environment. Take a certain amount of sodium carboxymethyl cellulose and dextran powder, mix them evenly, add them to a certain amount of deionized water, let them stand at room temperature, wait for complete swelling and dissolution, clarify the solution evenly, and place them in the refrigerator to keep. Weigh a certain amount of polyvinyl alcohol solution and polymethylcellulose sodium-dextran solution according to the proportion of insulin microneedle formula, and mix well. The uniformly mixed and bubble-free phase-converted hydrogel microneedle layer solution was poured into a height-adjustable glass plate recess. Another glass plate is covered on top of it, and the thickness and uniformity of the drug-loaded layer are controlled by adjusting the thickness of the adhesive tape at the corners of the glass plate, and then the four sides of the glass plate are clamped with a long tail clip. When the freeze-thaw process is completed, the phase-converted hydrogel microneedle layer film is removed and placed on a custom-made stainless steel-Teflon drying mold, and the layer film is placed into the desiccator together with the stainless steel drying mold. The dried microneedle drug-carrying layer was cut into small pieces and the thickness of the dry sheet was measured.
