title: In vitro evaluation of enhancing effect of borneol on transcorneal permeation of compounds with different hydrophilicities and molecular sizes.
abstract: 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.
authors: Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors: Hui-Ping
authors: HP
authors: Qi
authors: Xiang-Chun
authors: XC
authors: Gao
authors: Li-Qiong
authors: LQ
authors: Zhang
authors: Shu-Qin
authors: SQ
authors: Wei
authors: Sheng
authors: S
authors: Bi
authors: Zi-Chao
authors: ZC
authors: Yang
authors: Hao
authors: H
authors: Cui
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000494:pharmacology*; D000818:Animals; D001892:Camphanes / Q000494:pharmacology*; D003315:Cornea / Q000378:metabolism*; D003911:Dextrans / Q000737:chemistry / Q000378:metabolism; D019793:Fluorescein / Q000737:chemistry / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D010539:Permeability / Q000187:drug effects; D011817:Rabbits; D012235:Rhodamines / Q000737:chemistry / Q000378:metabolism
chemical_list: D000277:Adjuvants, Pharmaceutic; D001892:Camphanes; D003911:Dextrans; D005456:Fluorescent Dyes; D012235:Rhodamines; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate; C029773:rhodamine B; C022871:isoborneol; D019793:Fluorescein