Final answer:
Lotions are low-viscosity, while creams are higher viscosity and come in oil-in-water or water-in-oil types. There is no maximum dose mentioned for general moisturizing purposes, but medicated creams may have recommended application guidelines.
Step-by-step explanation:
The question refers to the categorization of skin creams and lotions, particularly in reference to their viscosity and usage. Lotions have a low-viscosity and are generally used to smooth, moisturize, and sometimes perfume the skin. By contrast, creams have higher viscosity, often due to having lower water content.
Creams are typically semi-solid emulsions of oil and water and can be categorized as oil-in-water (O/W) or water-in-oil (W/O) based on their composition. O/W emulsions are more cosmetically acceptable, less greasy, and can be washed off with water, while W/O emulsions provide a moisturizing oily barrier that reduces water loss. Considering these are topical preparations, there is not a specific "maximum dose" mentioned for cosmetic lotions and creams, as they are primarily used for moisturizing or cosmetic enhancements rather than medicinal purposes.
However, when creams are used as pharmaceutical products, the "finger tip unit" concept may guide how much cream to apply depending on the area being treated, though this information was not provided in the question. It is important to refer to the specific product's instructions or a medical professional for appropriate usage when dealing with medicated creams or lotions.