Timolol

• Latin: Timololum

• 26839-75-8
• 26921-17-5 (mono salt of maleic acid)

• C07AA06
• S01ED01

Crystalline solid

Beta blocker

Non-selective β -adrenoceptor antagonist

71.5 to 72.5 ° C

9.4

Slightly soluble in water ( 2740 mg · l-1 at 25 ° C)

Maleate

Attention

900 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Timolol is a chiral, enantiomerically pure drug from the group of beta blockers and is mainly used in eye drops for the treatment of open-angle glaucoma ( glaucoma).

Pharmacology

Timolol belongs to the group of the non- selective beta blocker, because it does not specifically bind to the β1 -adrenoceptors. It has no intrinsic sympathomimetic activity (ISA). The timolol inhibits the β2 - adrenergic receptors of the ciliary body of the eye and therefore reduces production of aqueous humor. The reduced aqueous humor formation leads to lowering of intraocular pressure. The relative potency of timolol compared to propranolol is 6

Pharmacokinetics

The fat- soluble timolol is well absorbed after oral administration, the bioavailability of timolol is about 50 to 60%. The plasma half-life of the timolol is about 4 to 5 hours. It is metabolized to 80% in the liver. The plasma protein binding of timolol is 60%. The Timolol is excreted in the kidney to 30%.

Synthesis

There are several synthetic routes for timolol. Starting from 3,4- dichloro-1 ,2,5 -thiadiazole and morpholine racemic timolol is produced in a five -stage process firstly. The resolution with ( )-tartaric acid then provides (S)- timolol, which is used as drug. Alternatively, enantiomerically pure timolol also from D- glyceraldehyde - be prepared - while avoiding a resolution.

Trade names

Arutimol (D), Betimol (A), Chibro - Timoptol (D), Dispatim (D), NyoGel (D), Nyolol (CH ), numerous generics (D)

AZARGA (A), Combigan (D, CH), Cosopt (D, CH), DuoTrav (D, CH), Fotil (D), Ganfort (D, CH), TP - Ophtal (D), Xalacom (D, CH )