目的:空心型微针(hMNs)是一种将药物有效施用到皮内部位的有前途的装置。为了获得生物利用度或恒定效果,必须实现将针完全插入皮肤中并施用药物溶液而没有泄漏。在本研究中,有或没有圆形钝尖微柱的几种类型的hMN,抑制皮肤变形,围绕着一根空心针,并研究了成功插入针头和药物溶液给药的效果。使用了六种不同类型的hMN,其针头长度为1000、1300和1500µm,有或没有微柱。
方法:研究大鼠皮肤中的针头插入和药物的处置。此外,还使用带有人工膜的质构分析仪研究了hMNs应用过程中的位移-力曲线,以通过与体内结果进行比较来检查影响药物溶液成功插入和给药的针头因素。
结果:根据碘的药物分布结果,具有微柱的hMN1300能够以很高的成功率成功地将药物溶液注射到皮内部位。此外,使用人造膜的位移-力曲线的结果表明,微柱可以有效地控制注入溶液的深度以及防止hMN基座与变形膜之间的接触。
结论:在本研究中,hMN1300S显示有效的溶液递送到皮内位点。特别是,微柱对于注射溶液的深度控制以及防止hMN基座和变形膜之间的接触是有效的。获得的结果将有助于hMN的设计和开发,以确保成功注射所给药物。
OBJECTIVE: Hollow-type microneedles (hMNs) are a promising device for the effective administration of drugs into intradermal sites. Complete insertion of the needle into the skin and administration of the drug solution without leakage must be achieved to obtain bioavailability or a constant effect. In the present study, several types of hMN with or without a rounded blunt tip micropillar, which suppresses skin deformation, around a hollow needle, and the effect on successful needle insertion and administration of a drug solution was investigated. Six different types of hMNs with needle lengths of 1000, 1300, and 1500 µm with or without a micropillar were used.
METHODS: Needle insertion and the disposition of a drug in rat skin were investigated. In addition, the displacement-force profile during application of hMNs was also investigated using a texture analyzer with an artificial membrane to examine needle factors affecting successful insertion and administration of a drug solution by comparing with in vivo results.
RESULTS: According to the results with the drug distribution of iodine, hMN1300 with a micropillar was able to successfully inject drug solution into an intradermal site with a high success rate. In addition, the results of displacement-force profiles with an artificial membrane showed that a micropillar can be effective for depth control of the injected solution as well as the prevention of contact between the hMN pedestal and the deformed membrane.
CONCLUSIONS: In the present study, hMN1300S showed effective solution delivery into an intradermal site. In particular, a micropillar can be effective for depth control of the injected solution as well as preventing contact between the hMN pedestal and the deformed membrane. The obtained results will help in the design and development of hMNs that ensure successful injection of an administered drug.