Pirenoxine

Pirenoxine (abbreviated PRX, trade name Catalin) is a medication used in the possible treatment and prevention of cataracts.

Pirenoxine

Clinical data
Trade names	Catalin
ATCvet code	QS01XA91 (WHO)
Identifiers
IUPAC name 1,5-Dioxo-4H-pyrido[3,2-a]phenoxazine-3-carboxylic acid
CAS Number	1043-21-6
PubChem CID	4846
ChemSpider	4846
UNII	27L0EP6IZK
CompTox Dashboard (EPA)	DTXSID6048335
ECHA InfoCard	100.012.612
Chemical and physical data
Formula	C16H8N2O5
Molar mass	308.249 g·mol−1
3D model (JSmol)	Interactive image
SMILES C1=CC=C2C(=C1)N=C3C(=CC(=O)C4=C3C(=O)C=C(N4)C(=O)O)O2
InChI InChI=1S/C16H8N2O5/c19-9-5-8(16(21)22)18-14-10(20)6-12-15(13(9)14)17-7-3-1-2-4-11(7)23-12/h1-6H,(H,18,19)(H,21,22) Key:OKPNYGAWTYOBFZ-UHFFFAOYSA-N

A report in the Inorganic Chemistry journal showed that in liquid solutions, pirenoxine could cause decreased cloudiness of a crystallin solution produced to mimic the environment of the eye. Pirenoxine interacts with selenite or calcium ions that have been proven as factors leading to the formation of lens cataract.^[1]

Pirenoxine reduces the cloudiness of the lens solution, containing calcium by 38% and reducing the cloudiness of the selenite solution by 11%.^[2]

“...there are not any proctored studies that prove the utility of these drops. In Canada and in the U.S. they are considered homeopathic—where they probably do no harm but doubtful that they will have any protective value."^[3]