THE next revolution in panty liners will be ones that change colour to warn
women they are about to ovulate. They can also tell if a woman has an
infection—or even when her period will start. Healthcare companies are
scrambling to patent the new approach first.
In the early 1990s, Media-Pharma of Germany, Kimberly-Clark of Wisconsin and
several private inventors separately filed patents on the idea of impregnating
sanitary towels and diapers with chemicals that changed colour according to the
concentration of glucose and nitrites in blood and faeces.
Now Procter & Gamble, maker of Always and Tampax, has…
