Methazolamide

Glaucoma is the leading irreversible blinding eye disease worldwide, among which high intraocular pressure is the core risk factor for the progression of optic nerve injury. As an oral carbonic anhydrase inhibitor for lowering intraocular pressure, methazolamide exerts a stable intraocular pressure-lowering effect by specifically inhibiting the activity of carbonic anhydrase in ciliary epithelium and reducing aqueous humor production. Moreover, it has a weaker impact on electrolyte metabolism than the同类 drug acetazolamide, with a lower incidence of adverse reactions. Its clinical indications include primary open-angle glaucoma, preoperative preparation for angle-closure glaucoma, and symptomatic treatment of secondary ocular hypertension. It is especially suitable for glaucoma patients intolerant to acetazolamide, and is an important alternative oral drug in the stepwise treatment of intraocular pressure reduction.

The market size of domestic intraocular pressure-lowering drugs is growing steadily, among which carbonic anhydrase inhibitors account for about 42% of the market share of oral intraocular pressure-lowering drugs. As the core variety of this category, methazolamide has a long-term stable annual sales volume of around RMB 310 million in public medical institutions, with a compound annual growth rate of approximately 2.7% in the past three years. At present, the domestic market supply is dominated by generic drugs. There are a total of 4 approved API manufacturers and 3 preparation manufacturers, with a relatively concentrated overall competitive landscape and no excessive homogeneous competition.

The original manufacturer of methazolamide is Cochlear Limited of Australia, with the original brand name of Neptazane. The core compound patent expired globally in 2008. The original formulation approved in China is tablets, available in 25mg and 50mg specifications, which has been included in the *Catalogue of Reference Preparations for Chemical Drugs (10th Batch)* issued by the National Medical Products Administration. In terms of domestic API registration, there are currently 4 domestic API registration numbers with A status, and the original manufacturer has not submitted API DMF registration in China. On the preparation side, in addition to the imported original drug, generic preparations from 2 domestic enterprises have been approved for marketing, both of which have passed the consistency evaluation. (Data as of April 2025, please refer to the official website of CDE for the latest information)

CATO provides a full set of impurity reference standards for methazolamide API, with most products in stock. For in-stock products, orders placed before 16:00 will be shipped on the same day. All products comply with the regulatory requirements of the Chinese Pharmacopoeia, FDA and other regulations, and can fully meet the full-process needs of API enterprises in the stages of R&D, quality research and registration application.