Evidence map›Paper›PMID 41111466›Full record

ArticleCurrent organic synthesis2025

Unveiling New Process Impurities in Ripasudil Hydrochloride Dihydrate: Identification, Synthesis, and Characterization.

Kedarnath M Birajdar, Sudhakar Arrahalli, Praveen Beekanhalli Mokshanatha, Prashanth Kumar Babu

Abstract read
PubMed Publisher
In one paragraph

Article in Current organic synthesis, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Kedarnath M BirajdarDépartement of Chemistry, Srinivas University Campus, Srinivas Nagara, Mukka, Surathkal, Mangalore, 574146, Katakana, India.ORCID 0009-0009-6327-6278
Sudhakar ArrahalliR&D, Department of Chemistry, Rajarajeswari College of Engineering, Ramohalli Cross, Kumbalagodu, Bengaluru, 560074, Katakana, India.ORCID 0000-0003-1330-8664
Praveen Beekanhalli MokshanathaDépartement of Chemistry, Srinivas University Campus, Srinivas Nagara, Mukka, Surathkal, Mangalore, 574146, Katakana, India.
Prashanth Kumar BabuDépartement of Chemistry, Srinivas University Campus, Srinivas Nagara, Mukka, Surathkal, Mangalore, 574146, Katakana, India.ORCID 0009-0008-7615-3384

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundRipasudil hydrochloride or 4-Fluoro-5-{[(2S)-2-Methyl-1,4- diazepan-1-yl] sulfonyl isoquinoline hydrochloride known as K-115 is used for the treatment of glaucoma and ocular hypertension. In the API industry, to achieve and ensure the quality of drug substances, there is a need for impurity identification, synthesis, and characterization. The impurities are formed during the process, either side reaction or degradation or carried over from the starting material.

objectivesThe present study explores two new process impurities of Ripasudil Hydrochloride dihydrate, specifically Impurity-1(4-fluoro-5-{[(3R)-3-methyl-4-(2- nitrolbenzenesulfonyl)-1,4-diazepan-1-yl] sulfonyl} isoquino line) and Impurity-2 (4- fluoro-N, N-dimethyl isoquinoline-5-sulfonamide). These impurities are critical to the quality of both the drug substance and the final drug product.

methodsThe API crude samples were subjected to LC-mass spectrometry for the identification of unknown impurities and further based on the observed mass values, a strategic synthetic route was designed for the synthesis of unknown impurities. The synthetic routes for these impurities were developed to avoid column purification, achieving high yields and purity.

resultsThe above synthesized impurities were subjected to spectral analysis like mass spectrometry, 1H NMR, and 13C NMR and confirmed the desired structure of the unknown impurities. So, as far as we know, the two impurities are new process impurities and have not been reported in the literature.

conclusionThe two new process impurities have been prepared and used as impurities for the method development and quality evaluation of the Ripasudil drug substance. Given the regulatory significance of Ripasudil hydrochloride, our successful synthesis and characterization efforts have proven to be valuable. This research offers valuable insights into the generic pharmaceutical industry.

Indexed as

Drug ContaminationIsoquinolinesSulfonamidesUreaMolecular StructureIsoquinolinesK-115SulfonamidesUreaAPIDMFHPLCprocesses impuritiesRipasudil hydrochloridewater.

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.