Stable cosmetic compositions with different pH emulsions
US5935589A · kind A · utility
22Cited by
1References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Oct 17, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61Q19/08
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The inventive compositions contain an oil-in-water and a water-in-oil emulsion, each buffered to a specific pH, so that the difference in pH values of the two emulsions is at least two units. The molecular mixing is minimized by selecting suitable oil and oil phase in a water-in-oil emulsion. The change in pH is further minimized by buffering each emulsion. The particular advantage of the inventive compositions is the ability to separate within a single composition, with minimal intermixing, active compounds which require different pH environments for stability and/or optimum efficacy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.