Ripasudil is a selective Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor used as an ophthalmic pharmaceutical ingredient. The pharmaceutical form is generally Ripasudil Hydrochloride Hydrate/Dihydrate, also known as K-115. It is used in ophthalmic formulations for the management of elevated intraocular pressure associated with glaucoma and ocular hypertension.
Ripasudil was developed as a ROCK inhibitor that acts on pathways involved in regulation of the trabecular meshwork and aqueous humor outflow. Its mechanism makes Ripasudil an important pharmaceutical API for ophthalmic drug development and manufacturing.
Ripasudil API is a synthetic small-molecule compound belonging to the isoquinoline class. The commercially relevant pharmaceutical material is Ripasudil Hydrochloride Dihydrate, with CAS No. 887375-67-9 and molecular formula C15H23ClFN3O4S. PubChem reports a molecular weight of 395.9 g/mol for the hydrochloride dihydrate form.
Ripasudil free base is identified separately as CAS 223645-67-8, with molecular formula C15H18FN3O2S and molecular weight 323.4 g/mol.
The hydrochloride hydrate form is the pharmaceutical form associated with products such as Glanatec. Ripasudil Hydrochloride is also available as a research-grade ROCK inhibitor for pharmaceutical and laboratory applications.
Ripasudil contains a fluorinated isoquinoline structure linked to a methyl-substituted diazepane ring through a sulfonyl group. Its stereochemistry is important because the active molecule contains a defined stereocenter. PubChem identifies the hydrochloride dihydrate as 4-fluoro-5-[[(2S)-2-methyl-1,4-diazepan-1-yl]sulfonyl]isoquinoline hydrochloride dihydrate.
As a ROCK inhibitor, Ripasudil influences actomyosin contractility and cellular cytoskeletal signaling. In ophthalmic applications, inhibition of ROCK signaling can promote aqueous humor outflow and contribute to reduction of intraocular pressure.
Ripasudil Hydrochloride Dihydrate is described as a solid pharmaceutical material. Commercial and research sources identify it as a white to off-white powder, while analytical characterization can include HPLC, spectroscopic identity testing and solid-state testing.
Ripasudil API is primarily associated with ophthalmic pharmaceutical formulations.
Its principal pharmaceutical application is the development and manufacture of medicines used for:
Ripasudil was first approved in Japan in 2014 as an ophthalmic ROCK inhibitor. PubChem identifies its use for glaucoma and ocular hypertension and describes the compound as a ROCK inhibitor.
The API is particularly relevant to ophthalmic formulations because ROCK inhibition can affect the trabecular meshwork and aqueous humor outflow pathways.
Ripasudil API requires appropriate analytical controls for identity, assay, purity and physical characteristics. HPLC is commonly used for purity and assay determination, while IR, LC-MS and other analytical techniques can support identification and characterization.
Quality evaluation may include:
Commercial reference material from Sigma-Aldrich is listed at ≥98% HPLC purity, while another commercial API source reports ≥99.0% HPLC purity. These values represent individual commercial specifications/reference materials and should not be treated as a universal pharmacopoeial acceptance limit.
Ripasudil API is a specialized ophthalmic pharmaceutical ingredient requiring appropriate control of chemical purity, stereochemical identity and the hydrochloride hydrate form.
A reliable Ripasudil API manufacturing program should focus on:
The exact API specification should be established according to the intended pharmaceutical application and validated manufacturing process.
Ripasudil API should be packed in suitable pharmaceutical-grade containers that protect the material from moisture, contamination and unsuitable environmental exposure.
Commercial research material is listed with desiccated storage conditions, while supplier specifications may recommend controlled room-temperature storage. The validated storage condition for commercial API should therefore be based on the manufacturer's stability data and applicable product specification.
Suitable packaging may include moisture-protective inner bags and tightly closed pharmaceutical containers.
Ripasudil API documentation may include:
Complete analytical documentation supports pharmaceutical development, quality evaluation and commercial API procurement.
Ripasudil is an established ROCK inhibitor with pharmaceutical applications in ophthalmology. Its defined chemical structure and established use in ophthalmic formulations make it an important API for glaucoma and ocular-hypertension drug development.
A quality-focused Ripasudil API program should provide:
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | NLT 98.0% |