Department of Pharmaceutics, Jamia Hamdard, New Delhi, India.
J Drug Target. 2011 Jul;19(6):409-17. doi: 10.3109/1061186X.2010.504268. Epub 2010 Aug 3.
Drug delivery to ocular region is a challenging task. Only 1-2% of drug is available in eye for therapeutic action, rest of the drug is drained out through nasolachrymal drainage system and other ocular physiological barriers. To overcome these problems of conventional dosage form, novel drug delivery systems are explored like nanoparticles. In our present work, levofloxacin encapsulated poly(lactic-co-glycolic acid) nanoparticles were developed and evaluated for various parameters like particle size, ζ potential, in vitro drug release and ex vivo transcorneal permeation. Microbiological efficacy was tested against Staphylococcus aureus using cup-plate method. Precorneal residence time was studied on albino rabbits by γ scintigraphy after radiolabeling of levofloxacin by Tc-99m. Ocular tolerance was evaluated using hen's egg chorioallantoic membrane (HET-CAM) test. The developed nanoparticles were of spherical shape with a mean particle size of 190-195 nm with a ζ potential of -25 mV. The drug entrapment efficiency was found to be near 85%. In vitro drug release profile shows initial burst release followed by extended release up to 24 h. Microbiological assay showed equivalent zone of inhibition compared to marketed formulation. γ Scintigraphy images of developed formulation, suggested a good spread and good retention over precorneal area. The nanosuspension thus developed was retained for the longer time and drained out from the eye very slowly compared to marketed formulation as significant radioactivity was recorded in later in kidney and bladder. The developed nanosuspension with a mean score of 0.33 up to 24 h in HET-CAM assay, showed the nonirritant efficacy of developed formulation. The stability studies yielded a degradation constant less then 5 × 10(-4), proving a stable formulation with an arbitrary shelf life of 2 years.
眼部给药是一项具有挑战性的任务。只有 1-2%的药物可用于治疗眼部疾病，其余的药物通过鼻泪液引流系统和其他眼部生理屏障排出。为了克服传统剂型的这些问题，人们探索了新型药物传递系统，如纳米颗粒。在我们目前的工作中，开发了包封左氧氟沙星的聚（乳酸-共-乙醇酸）纳米粒，并对其进行了各种参数的评价，如粒径、ζ电位、体外药物释放和离体角膜透过性。采用杯碟法对抗金黄色葡萄球菌进行了微生物功效测试。用 Tc-99m 对左氧氟沙星进行放射性标记后，通过 γ 闪烁照相法在白化兔上研究了角膜前停留时间。通过鸡胚尿囊膜（HET-CAM）试验评估了眼部耐受性。所开发的纳米粒呈球形，平均粒径为 190-195nm，ζ 电位为-25mV。药物包封效率接近 85%。体外药物释放曲线显示初始突释后持续释放长达 24 小时。微生物测定显示，与市售制剂相比，具有等效的抑菌环。开发制剂的 γ 闪烁照相图像表明，在角膜前区域有良好的扩散和保留。与市售制剂相比，纳米混悬剂保留时间更长，从眼部排出速度更慢，因为在肾脏和膀胱中记录到了显著的放射性。在 HET-CAM 试验中，开发的纳米混悬剂在 24 小时内的平均评分为 0.33，表明开发的制剂具有非刺激性作用。稳定性研究得到的降解常数小于 5×10(-4)，证明该制剂具有稳定的性质，任意保质期为 2 年。
