Dorzolamide Hydrochloride

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Cat Number

API0232118

CAS Number

130693-82-2

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Product Detail Description Scientific Support Customer Q&A

CAS Number

130693-82-2

EINECS

620-304-2

Storage

Store at room temperature

Synonyms

Dorzolamide HCl; DTXSID1045530; QZO5366EW7; DTXCID9025530; CHEBI:4703; Dorzolamide PF

Molecular Formula

C10H17ClN2O4S3

Molecular Weight

360.9

Smiles

CCN[C@H]1C[C@@H](S(=O)(=O)C2=C1C=C(S2)S(=O)(=O)N)C.Cl

Appearance

White to off-white powder

Melting Point

283-285°C

Boiling Point

575.8°C at 760 mmHg

Relative Density

1.53

General Description

Dorzolamide hydrochloride is a potent, water-soluble topical carbonic anhydrase inhibitor (CAI) belonging to the thienothiopyran-2-sulfonamide class. Its chemical structure contains a bicyclic thienothiopyran ring with a sulfonamide group, which is responsible for enzyme binding. The hydrochloride salt enhances solubility. Unlike systemic CAIs (acetazolamide), dorzolamide is designed for topical application with minimal systemic absorption due to its polarity.

Mechanism of Action

Dorzolamide selectively and reversibly inhibits carbonic anhydrase isoform II (CA-II) in the ciliary epithelium of the eye. This inhibition reduces the production of bicarbonate ions, which in turn decreases the active transport of sodium and water into the aqueous humor. The net effect is a reduction in aqueous humor secretion and a consequent lowering of intraocular pressure (IOP).

Application

Dorzolamide is indicated for the treatment of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension, either as monotherapy or in combination with beta-blockers or prostaglandin analogs. It is particularly useful in patients who are intolerant to or insufficiently responsive to beta-blockers. The drug may cause local irritation, blurred vision, and metallic taste due to systemic absorption through the nasolacrimal duct.

In 4‑ and 9‑month‑old DBA/2J glaucomatous mice and C57BL/6 controls, topical dorzolamide (DZ) lowered intraocular pressure (IOP) in both age groups of DBA/2J mice (but not in controls) at 1 and 2 hours. Baseline retinal blood flow was lower in DBA/2J mice at both ages, and choroidal flow was lower in 9‑month‑old DBA/2J mice. Dorzolamide increased both retinal and choroidal blood flow in the older DBA/2J mice. The results support the hypothesis that DZ lowers IOP and also improves ocular blood flow in glaucomatous mice.

Fig. 1 Mean IOP measurements for 4-month-old C57BL/6J, 4-month-old DBA/2J, and 9-month-old DBA/2J mice at baseline and at 1 and 2 hours post-DZ as well as 9-month-old DBA/2J mice before and after topical saline. (Chandra S, et al., 2016)

References

Chandra S, et al. Effects of Dorzolamide on Retinal and Choroidal Blood Flow in the DBA/2J Mouse Model of Glaucoma. Invest Ophthalmol Vis Sci. 2016;57(3):826-831.

Does Dorzolamide Hydrochloride require protection from light during storage?

Yes, it is photosensitive. UV light can cause photodegradation and formation of the thienothiopyran-related impurity. Store in light-resistant containers.

What is the recommended storage temperature for Dorzolamide Hydrochloride?

Store at controlled room temperature (15-25°C). Avoid excessive heat above 30°C, which can accelerate hydrolysis of the sulfonamide group.

Is Dorzolamide Hydrochloride stable in ophthalmic solution formulations?

Yes, when formulated with preservatives (e.g., benzalkonium chloride) and protected from light.

How is the impurity dorzolamide N-oxide (an oxidative degradation product) monitored?

This degradation product is quantified using a stability-indicating HPLC method, ensuring it remains within ICH qualification thresholds.