Wilkinson Sword was founded in 1772, and its origins began with the manufacture of swords and, later, guns and shears. In 1898, the company branched out to manufacture safety razors and became a U.K.-leader in shaving products. In the 1960s, it introduced stainless steel razor blades coated with PTFE (polytetrafluoroethylene), which in 1967 brought one of the present authors (David Rowsell) to the company. With a background in fluorine chemistry, the author’s project at the time was to investigate PTFE alternatives.
Late 1960s to the 1980s: Pursuing New Compounds
However, around 1969–1970, Wilkinson Sword management wanted to expand/diversify and proposed products in the toiletries/cosmetics area, and thus the R&D focus shifted. This proposal was developed further (mostly by Wilkinson Sword researcher Hugh Watson) into pursuing compounds with a menthol-like cooling effect, no odor and low volatility. This idea was attractive because one of the major negatives of menthol- containing shaving creams and after-shave lotions was the propensity for eye and mucus membrane irritation. A literature search indicated that these compounds were likely to be novel. The only cooling compounds other than menthol known at that time seemed to owe their properties to hydrolysis to menthol.
It appeared from published physiological studies that the interaction of menthol with “cold receptors” in the skin could be interpreted as a drug-receptor type of interaction. A structure-activity relationship (SAR) approach using the methodology introduced by Hansch et al. in the mid-1960s was applied. General principles that were developed based on correlations observed in work on acetylcholine drug-receptor interactions were applied in addition to SAR methods.