2. Unique Features of Perfumes

The main distinguishing feature of a fragrance compared to other active ingredients is the diversity of its composition. While it is standard practice in pharmacology and cosmetics to encapsulate only single, chemically well-defined substances or chemically homogeneous mixtures—such as vegetable oils—fragrances consist of a large number of ingredients that are very different from one another. This diversity is expressed through chemical functions (alcohols, esters, ethers, ketones, aldehydes…), structural characteristics (rings, branches, unsaturations, aromaticity…), physicochemical properties (vapor pressure, polarity…), and sensory attributes (olfactory direction, impact, transparency…). Furthermore, a fragrance is intended to please the consumer, and its hedonistic dimension is its raison d’être: a fragrance is a subtle creation in every case, even if it is ultimately used in a toilet...