Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, China.
Eur J Pharmacol. 2013 Apr 5;705(1-3):20-5. doi: 10.1016/j.ejphar.2013.02.031. Epub 2013 Feb 28.
To investigate the enhancing effect of borneol on transcorneal permeation of compounds with different hydrophilicities and molecular sizes. Six compounds, namely rhodamine B, sodium-fluorescein, fluorescein isothiocyanate (FITC) dextrans of 4, 10, 20 and 40 kDa were selected as model drugs. Permeation studies were performed using excised cornea of rabbits by a Franz-type diffusion apparatus. The safety of borneol was assessed on the basis of corneal hydration level and Draize eye test. The application of 0.2% borneol to the cornea increased the apparent permeability coefficient by 1.82-(P<0.05), 2.49-(P<0.05), 4.18-(P<0.05) and 1.11-fold (not significant) for rhodamine B, sodium-fluorescein, FITC-dextrans of 4 and 10 kDa, respectively. No significant permeability enhancement of FITC dextrans of 10, 20 and 40 kDa with borneol was found compared to control. The permeability coefficient enhanced by 0.2% borneol was linear correlated to the molecular weight of model drugs (R(2)=0.9976). With the 0.05%, 0.1% and 0.2% borneol application, the corneal hydration values were <83% and Draize scores were <4. Borneol may improve the transcorneal penetration of both hydrophilic and lipophilic compounds without causing toxic reactions, especially hydrophilic ones. Furthermore, 0.2% borneol can enhance the permeation of hydrophilic compounds with molecular weight ≤4 kDa. Hence, borneol can be considered as a safe and effective penetration enhancer for ocular drug administration.
考察冰片对不同亲水性和分子大小的化合物经角膜渗透的增强作用。方法：选择 6 种化合物，即罗丹明 B、荧光素钠、4、10、20 和 40 kDa 的荧光素异硫氰酸酯葡聚糖作为模型药物。采用 Franz 型扩散装置，通过离体兔角膜进行渗透研究。根据角膜水化水平和 Draize 眼试验评估冰片的安全性。将 0.2%的冰片应用于角膜，可使罗丹明 B、荧光素钠、4 kDa 的 FITC 葡聚糖的表观渗透系数分别增加 1.82 倍（P<0.05）、2.49 倍（P<0.05）、4.18 倍（P<0.05）和 1.11 倍（无显著差异）。与对照相比，冰片对 10、20 和 40 kDa 的 FITC 葡聚糖的渗透增强作用不明显。用 0.2%的冰片增强的渗透系数与模型药物的分子量呈线性相关（R（2）=0.9976）。应用 0.05%、0.1%和 0.2%的冰片时，角膜水化值<83%，Draize 评分<4。冰片可改善亲脂性和亲水性化合物的经角膜渗透，而不会引起毒性反应，尤其是亲水性化合物。此外，0.2%的冰片可增强分子量≤4 kDa 的亲水性化合物的渗透。因此，冰片可被视为眼部给药的安全有效的渗透增强剂。
