Dorigo M T, De Natale R, Miglioli P A
Ocular Pharmacology Center, University of Padua, Italy.
Chemotherapy. 1995 Jan-Feb;41(1):1-4. doi: 10.1159/000239317.
Collagen shields have been used as therapeutic contact lenses to promote corneal epithelial healing and to deliver hydrosoluble drugs. In albino rabbits, we studied the ocular pharmacokinetics of netilmicin, an aminoglycoside antibiotic, released by a 24-hour collagen shield immersed for 10 min in commercially available eye solution of netilmicin, at the standard concentration of 3 mg/ml. The animals were sacrificed after 0.5, 1, 6 and 18 h. The antibiotic concentrations were measured by the microbiological method. The drug levels remained above the MIC for the usual pathogens for 18 h in the cornea and for 6 h in the aqueous humor. In the iris and ciliary body the peak concentration was reached 1 h after shield application, netilmicin concentration decreased thereafter rapidly. The lens and the vitreous did not appear to be permeated by the drug. In the conjunctiva, drug concentrations were low, showing a negligible lateral diffusion of netilmicin released by shields. In conclusion, our findings show, that if the collagen shields are used as delivery systems, a very concentrated drug solution is not required to obtain high and persistent levels of netilmicin in cornea.
胶原盾已被用作治疗性隐形眼镜，以促进角膜上皮愈合并递送水溶性药物。在白化兔中，我们研究了奈替米星（一种氨基糖苷类抗生素）的眼内药代动力学，该药物由在市售浓度为3mg/ml的奈替米星眼药水中浸泡10分钟的24小时胶原盾释放。在0.5、1、6和18小时后处死动物。通过微生物学方法测量抗生素浓度。药物水平在角膜中对于常见病原体保持高于最低抑菌浓度18小时，在房水中保持6小时。在虹膜和睫状体中，在应用胶原盾1小时后达到峰值浓度，此后奈替米星浓度迅速下降。晶状体和玻璃体似乎未被药物渗透。在结膜中，药物浓度较低，表明胶原盾释放的奈替米星横向扩散可忽略不计。总之，我们的研究结果表明，如果将胶原盾用作递送系统，则不需要非常浓缩的药物溶液即可在角膜中获得高且持久的奈替米星水平。
