What does the SR stand for in Gibbs SR toothpaste?

The only website that gave an answer was unavailable. Nearly everybody knows that it was the first advert on British TV but I did not know that the commercial owed its prime placing to chance. The Gibbs advertisement had come first in a lottery drawn with 23 other advertisements, including those for Guinness, Surf, National Benzole, Brown and Polson Custard and Summer County Margarine.

The letters SR stand for sodium ricinoleate, one of the active constituents of the product that makes it, so says the slogan, 'tingling fresh'. In other words,and from personal experience, it makes your mouth feel like it's on fire.

Thanks to both Son Of The Household Cavalry and mk2norwich for your answers.

Also, does the name Gibbs in the toothpaste name relate in any way to the Gibbs family who used to own Tyntesfield, near Bristol, now owned by the National Trust?

The name Gibbs refers to the family that owned the company at the time, and later merged with Lever Bros (now Unilever). The family live in Essex.