Penetration of timolol eye drops into human aqueous humour.

One to 7 hours after instillation of 0 5% timolol eye drops the aqueous humour aspirated from patients about to have cataract extraction showed concentrations of timolol ranging from 150 ng per 100 mg in the first I or 2 hours to 10 ng per 100 mg towards the end of the 7 hours. An exponential decay curve fitted the data well.There is now ample evidence of the efficacy of timolol, a 8,3 and 32 adrenergic blocking agent, in lowering