Prescription process and in vitro study of transdermal patch and microneedle combination formulation of progesterone

To prepare a progesterone pressure-sensitive gel patch combined with a microneedle to enhance drug release, HPLC was used to determine the preparation's progesterone content. One-way and orthogonal experiments were used to optimize the patch's prescription. Adhesion, sensory evaluation, cumulative release, and cumulative penetration were used as evaluation indices. Three microneedles with varying needle heights were made using 3D printing, and the cumulative penetration of the patch and microneedles was calculated and compared with the patch alone. The orthogonal experiments showed that the optimal prescription for the patches was Duro-Tak 87-2677 pressure-sensitive adhesive (87.5%), tributyl citrate (2%), isopropyl myristate (5%), dibutylated hydroxytoluene (0.5%), and drug (5%). The patches were prepared according to the optimized prescription, resulting in good patch formability and adhesion. In the transdermal penetration test, the cumulative penetration of the patch was 52.35 ± 7.88 μg·cm^-2 at 24 h, and the cumulative penetration of the patch in combination with 500, 750, and 1 000 μm microneedles was 226.01 ± 7.46, 278.78 ± 6.59, 422.95 ± 16.81 μg·cm^-2, respectively. The experiment was approved by the Experimental Animal Ethics Committee of Xinjiang Medical University (IACUC-20220725-8). The optimal patch prescription was screened through one-way and orthogonal experiments, and the transdermal penetration effect of patch and microneedle combination preparation was better than that of single use, which can effectively increase the in vitro transdermal penetration of the drug, and the above study provides a theoretical basis for the application of transdermal patches of progesterone.