インドメタシンとリドカイン複合体の経皮吸収の検討

抄録

The purpose of this study is to develop new ointments containing the complex of indomethacin (IDM) and lidocaine (LDC) for alleviation of the pain of post-herpetic neuralgia. Methylcellulose-based hydrogel ointment was prepared with a molar ratio of LDC to IDM of 1 or 10.5. The concentration of IDM was fixed at 1% (w/w). The skin permeation of IDM and/or LDC was evaluated using hairless mouse skin with the flow-through-cell method. The amount of IDM permeating from the IDM/LDC (1:1) ointment was about 6-fold higher than that from the ointment containing IDM alone. This can be attributed to the fact that the solubilities of IDM in octanol and water increase in the IDM/LDC (1:1) ointment compared to the ointment containing IDM alone due to the formation of a complex. The amount of IDM permeating from the IDM/LDC (1:10.5) ointment was about 2.2-fold higher than that from the IDM/LDC (1:1) ointment. In contrast, the amount of LDC permeating from IDM/LDC (1:1) ointment decreased to 40% compared to the ointment containing LDC alone (0.65% (w/w)) which was equivalent to the amount used in IDM/LDC (1:1) ointment. However, as the molar ratio of LDC in IDM/LDC ointment was increased from 1 to 10.5 (LDC: 6.9% (w/w)), the amount of LDC permeating from IDM/LDC (1:10.5) ointment was nearly equal to that from the ointment containg LDC alone (6.9%) which is equivalent to the amount used in clinical practice. In such a novel IDM/LDC ointment is a potential formulation to alleviate the pain of post-herpetic neuralgia.