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O/W emulsion
• Are generally chosen for applications that require a relatively small amount of fatty
materials,
• Example: hair conditioners, shaving creams, or facial moisturizing creams

W/O emulsion
• Are preferred when a larger amount of oil is desired in the formulation
• They are greasier, leave a longer-lasting residue, and are more water resistant (as they
contain oils in the outer phase).
• W/O emulsions are preferred in diaper rash products

Water-in-silicon (W/Si) emulsions

• They are important as they provide a unique, nongreasy skin feel and quick drying effect,
leaving the skin smooth.

• Examples for such formulations include:
➢ Facial foundations
➢ Cream eyeshadows
➢ Sunscreens.

2. Ointments:

• Ointments have a less aesthetic appeal for skin care and dermatology products as they are
oily, waxy, greasy, sticky, tacky, and heavy.

• They are advantageous for smaller skin areas that are extremely dry and need moisture
retention, and for areas that are prone to friction from clothing and need protection.

• Ointments are often opaque and yellowish due to the high amount of oils.

• Due to the undesired skin feel, there are only a small number of cosmetic products
formulated as ointments.

• Examples include :
➢ Some hair styling products (base???)
➢ Diaper rash ointments (base???)

3. Pastes:
From a cosmetic perspective, pastes as dosage forms can be used as diaper rash treatment products.
There is a huge difference between “regular” paste and toothpaste from the vehicle’s perspective:

➢ Regular pastes are anhydrous formulations, based on a fatty vehicle; therefore, they are
highly adhesive to surfaces and hard to remove with water.

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