# How to Make Stable, High-Water Content Skin Creams

> A recipe for creating stable skin lotions that are mostly water but feel like rich, oily creams by using specific silicone emulsifiers and carefully balanced oils.

- **Patent:** US 6793929
- **Original title:** Preparations of the w/o emulsion type with an increased water content, comprising moderately polar lipids and silicone emulsifiers and, if desired, cationic polymers
- **Owner:** Beiersdorf AG
- **Granted:** 2004
- **Status:** Public domain (expired)
- **Times cited:** 25
- **Field:** consumer_electronics, materials

## What it does

This patent describes a way to mix a large amount of water (at least 80% of the total weight) into an oil-based cream without the mixture separating. Usually, oil and water don't like to mix, but the inventors use specific 'interface-active' substances—specifically alkylmethicone or alkyldimethicone copolyols—to act as a bridge between the two. The oil phase is carefully chosen to have a specific 'polarity' (a measure of how the oil molecules interact with water) between 20 and 30 mN/m. This allows the product to remain a thin, spreadable liquid (with a viscosity under 5000 mPa·s) while still delivering the benefits of a moisturizing cream.

## What it does NOT cover

- Does not cover emulsions where the water content is less than 80% by weight.
- Does not cover oil phases with a polarity outside the specific 20-30 mN/m range.
- Does not cover creams that are thick, paste-like, or have a viscosity higher than 5000 mPa·s.
- Does not cover emulsions that use standard emulsifiers not listed as alkylmethicone or alkyldimethicone copolyols.

## The clever bit

The invention relies on the precise tuning of the oil phase's polarity to match the silicone emulsifiers, allowing for a stable, low-viscosity emulsion even when water makes up the vast majority of the product.

## Real-world examples

1. Lightweight facial lotions
2. Hydrating body mists
3. Oil-in-water style skin serums

## Why it matters

Consumers often want the light, cooling feel of water-based products but the long-lasting moisturizing effects of oil-based creams. This patent provided a technical framework for Beiersdorf to create high-water-content products that don't feel greasy or heavy, which is a staple in modern skincare formulations. It helps manufacturers balance the 'fresh' sensory experience of water with the performance of lipids.

## Frequently asked questions

### What does How to Make Stable, High-Water Content Skin Creams cover?

A recipe for creating stable skin lotions that are mostly water but feel like rich, oily creams by using specific silicone emulsifiers and carefully balanced oils.

### Who owns patent US 6793929?

Beiersdorf AG owns this patent, granted in 2004.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 6793929 cited by?

This patent has been cited by 25 later patents that build on its ideas.

### What problem does this patent solve?

Consumers often want the light, cooling feel of water-based products but the long-lasting moisturizing effects of oil-based creams. This patent provided a technical framework for Beiersdorf to create high-water-content products that don't feel greasy or heavy, which is a staple in modern skincare formulations. It helps manufacturers balance the 'fresh' sensory experience of water with the performance of lipids.

### What does this patent NOT cover?

Does not cover emulsions where the water content is less than 80% by weight.

**Full plain-English explainer:** https://patentbrief.org/patent/us/6793929/herceptin-chemotherapy-combination

**Original patent:** https://patents.google.com/patent/US6793929

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._