Conopco Inc. has published a patent describing extruded bar soap compositions that deliver actives more effectively and demonstrate a higher fragrance impact.
According to the disclosure, in milled and plodded soap, the bar is prepared with high water content, then spray-dried to reduce the moisture levels and cool the soap, after which other ingredients are added. The soap is then extruded through a plodder and optionally cut and stamped to prepare the final soap bar.
Soap Structure
These soaps generally have high amounts of total fatty matter (TFM) (60%-80% w/w) and comprise both water-insoluble and water-soluble soaps. The water-insoluble soaps usually consist of high amounts of higher chain C16 and C18 soap (stearate and palmitate soap) and are included in soap bars to provide structuring benefits. The water-soluble soaps aid in cleansing and are generally unsaturated C18:1 and 18:2 sodium soap (oleate soap) in combination with short chain fatty acids (C8 to C12, or even up to C14 soap).
The present inventors have identified a specific balance of soap ingredients that exhibits better bloom (perfume impact) and better deposition of actives, compared with conventional soap bars.
Improved Perfume Impact, Deposition of Actives
This patent disclosure describes a soap bar with improved perfume impact and deposition of actives, which is obtained by balancing amounts of oleate soap with ricinoleate soap. More specifically, Conopco inventors found that when the amount of unsaturated higher chain fatty acid soaps, e.g., oleate soaps, is minimized or eliminated from the soap composition, it is possible to achieve higher perfume impact and better delivery of actives on to skin.
However, when such oleate soaps are not included, it is reportedly difficult to extrude such soap masses. By replacing the oleate fraction with some amount of sodium ricinoleate, in combination with short chain fatty acid soap (C-8 to C12), this challenge was overcome. The resulting compositions are said to exhibit vastly improved perfume impact and enhanced deposition of actives, compared with conventional soapd comprising oleates.