Hi Kate,
I've never seen that remedy, but assume it is either a nosode or a compound homeopathic. Maybe you could google it?
We use a variety of products, depending on the particulars of the case. For a serous discharge, minimal in volume, and with the cat mildly but persistently affected, Yu Ping Feng San (Jade Wind Screen Combination) works well. It's an immune stimulant.
For more copious eye and nose discharge, San Ren Tang (Three Seeds Decoction) works well. It's an anti-inflammatory, at least in part.
For homeopathics, consider Allium cepa 30C when there is a lot of sneezing, squinting and nasal discharge in particular. Use Euphrasia 30C if the problem is more centered in the eyes, with the nose less involved.
Lastly, vitamin A has significant immune stimulating effects and promotes greater integrity of the epithelia to resist bacterial and viral infection.
Hopefully one of those will sound like your cat.
Steve