Ocular Drug Delivery Systems of Antiglaucoma Agents

青光眼治療劑之眼輸藥系統

江樵熹(Chiao-Hsi Chiang)

《Journal of Medical Sciences》 12卷3期 (1991/12) Pp. 157-170

摘要

青光眼是由於眼內壓（IOP）過高而導致視覺障礙的疾病。一般人的跟壓約在15.5±2.57mmHg，若眼壓高至20.5mmHg則懷疑是青光眼患者，若高至24mmHg則確定有青光眼症狀。眼睛由於生理結構特殊的限制，以至於眼藥的眼生體可用率不佳，這些因素包括淚液的流失，結合膜囊的容量太小，反射性的流淚，及藥液濺落臉頰。應用於青光眼治療藥物主要有三類，包括縮瞳劑、β一阻斷劑及酸酸酐酶抑制劑。碳酸酐酶抑制劑目前已正發展能局部投用在眼睛的藥物，如具有療效的MK-927， 6-aminozolamide及6-hydroxyetboxyzolamide。在選擇藥物時，需要藥物有良好的溶解度、適當的抽水分配係數以增進藥物的眼角膜穿透速率。此外在配方因素的考慮包括溶液的pH值、等張性、黏稠度及固體藥物的粒子等，皆能夠影響製劑的眼主體可用率。固體的薄膜劑、眼嵌劑及半固體的凝膠劑也能促進眼藥的療效。一個良好的眼輸藥系統其特性是能夠控制藥物的釋出速率、沒有毒性且病人能夠舒服的使用。

關鍵字

青光眼藥物 ； 眼藥輸藥系統 ； 眼角膜穿透性

並列摘要

Glaucoma is a disease with a characteristic of higher level of intraocular pressure (IOP) which might progressively hurt visibility. The average IOP of population is 15.5±2.57 mmHg. If people whose IOP is 20.5 mmHg or more, could be suspected of having glaucoma, and IOP over 24 mmHg were definite case of glaucoma. Because the constraint of physiological factors, the ocular bioavailability of ophthalmics is much lower much other dosing route. These factors are lacrimal drainage, lower cul-del-sac volume. reflex tearing and drug spillage onto the cheek.Most available antiglaucoma drugs are miotics, β-blockers and carbonic anhydrase inhibitors. Recently, topical carbonic anhydrase inhibitors have been developed for directly topical administration of arug in the eye. Some compounds had been found with potential therapeutical effect such as MK-927. 6-aminozolamide and 6-hydroxyethoxyzolamide. An ideal ophthalmic should have suitable aqueous solubility and appropriate lipophilicity or distribution coefficient to enhance the corneal penetration rate of drug. In addition, the formulation factors were also improtant which included pH. viscosity, tonicity and panicle size of solid drug. These factors have dramatic effect on the ocular bioavailability of ophthalics.Patients used ophthalmics of solid film, ocusert and gel to obtain better therapeutic effect than traditional ophthalmics. A suitable ocular drug delivery system should have the characteristics of non-toxic and comfortable for patient use. In addition, ophthalmic should preferably release drug at a controlled .rate to prolong the effect in reducing IOP.

並列關鍵字

Antiglaucoma Drugs ； Ophthalmics ； Drug Delivery Systems ； Corneal Permeability