Application of composite dissolving microneedles with high drug loading ratio for rapid local anesthesia

• Published in: European journal of pharmaceutical sciences 2018-08, Vol.121, p.330-337
• Main Authors: Zhan, Haohui, Ma, Fengsen, Huang, Yingcong, Zhang, Jie, Jiang, Xiayun, Qian, Yongchang
• Format: Article
• Language: English
• Subjects: Dissolving microneedles; Drug loading ratio; Lidocaine hydrochloride; Local anesthesia
• ISSN: 0928-0987; 1879-0720
• DOI: 10.1016/j.ejps.2018.06.014

We report a type of dissolving microneedles (DMNs) which was made of composite matrix materials of hydroxypropyl methyl cellulose (HPMC) and poly(methylvinylether‑co‑maleic anhydride) (PMVE/MA copolymer, Gantrez S-97), and was successfully loaded with lidocaine hydrochloride. The weight of lidocaine hydrochloride loaded in the microneedles tip was 70% of the weight of the whole tip. The content was 3.43 ± 0.12 mg in weight, which was determined by high performance liquid chromatography (HPLC). The results for mechanical test showed that these microneedles were able to penetrate into the skin of the experimental animals, that was proved using organic staining, texture analyzer and histological examination. The fracture force of the microneedles was 5.442 ± 0.412 N, which was much higher than the one required for the skin penetration. The DMNs with lidocaine hydrochloride could be dissolved inside of the rat skin in 5 min. The onset time would be faster (in