[Preparation and performance evaluation of controlled-release chitosan-based microneedles].

In clinical application, a microneedle system that continuously delivers drugs is of great value for the delivery of some vaccines and hormone drugs. In this study, a controlled-release chitosan-based microneedle array (PVA/CS-MN) was designed, combining microneedle patches with drugs for controlled-release of drugs. Here we report the optimization of the preparation process of PVA/CS-MN. The appearance, morphology, mechanical properties, dissolution and swelling properties, and in vitro penetration properties of the MN arrays were characterized. The PVA/CS-MN prepared by the optimal process showed good morphology and mechanical properties. PVA/CS-MN can smoothly open microchannels on the skin and achieve controllable dissolution and swelling functions. Ascorbic acid (l-ascorbic acid) was used as a model drug to prepare a Vc-PVA/CS-MN. Invitro transdermal diffusion experiments showed that the Vc-PVA/CS-MN released about 57% of the drug within 1 h. About 66.7% of the drug was slowly released within 12 h, and a total of 92% of the drug was released after 7 days. The controllable sustained-release properties and excellent drug delivery efficiency of PVA/CS-MN provide a new option for sustained transdermal drug delivery.