Who Put the "Mmmm" in the Eye Drops?

When I was a kid there was a TV ad campaign for Murine Eye Drops that had a little jingle that went: "Who put the 'Mmmm' in the eye drops? Murine!" Well, after seeing that ad for the first time, my sister said: "Well, it's a good thing they put the 'Mm' in the eye drops, because otherwise it would just be urine." And the way Murine is spelled, take away the 'M', and it spells 'urine'. I can't believe that nobody caught that problem before it became a real ad campaign and ran on TV, but apparently nobody did.

I'm sorry, but I cannot find this ad on YouTube, but I swear to you this was an ad campaign for Murine Eye Drops when I was a kid.