Table 4.

Various kinds of moisturizer formulations^{10,19, 20}

Classification	Lotions	Creams	Ointments	Gel
Phase	Oil in water (O/W)	Water in oil (W/O) (hydrophobic) or O/W (hydrophilic)	W/O (hydrophobic)/ or O/W (hydrophilic)	Hydrophobic or hydrophilic
Preparation	O/W prepared with emulsifiers to enhance spread ability	O/W creams are prepared at elevated temperature, followed by reduction to room temperature for internal phase to solidify oil and water (50% each)	Does not contain enough water to separate into second phase at room temperature. Most contain 80% oil and 20% water	Has liquid phase in a three dimensional polymeric matrix with physical or sometimes chemical cross linkage with appropriate gelling agent
Composition	Oil, Water, Propylene glycol	W/O: emulsifier such as monoglycerides, sorbitan esters and wool fat O/W: emulsifying agents such as sodium or triethanolamine soaps, sulfated fatty alcohols and polysorbates. When necessary may be combined with W/O emulsifying agents	W/O: water insoluble hydrocarbons such as paraffin, vegetable oil, animal fats, waxes, synthetic glycerides and polyalkysiloxanes O/W: mixtures of liquid and solid polyethylene glycols (macrogols)	Hydrophobic gel (oleogel): Liquid paraffin with polyethylene or fatty oils gelled with colloidal silica, alumunium, or zinc soaps Hydrophilic gel (hydrogel): water, glycerol or propylene glycol gelled with suitable agents such as tragacanth, starch, derivatives of cellulose, carboxy vinyl polymers and magnesium/alumunium silicates
Properties	Non greasy, thinner, easily spreads to cover large areas	Esthetic. Made of heavier lipids	Greasy, glossy look following application Forming skin’s protective layer, particularly useful in low humidity (< 60%) environment	Smooth finishing, non oily, non comedogenic, absorbs easily
Usage	Daytime moisturizer for face and body. After shave lotions, for application on hairy areas	Night time moisturizers for face hand, and non hairy body parts To use when no occlusive effect is required	Particularly beneficial when high degree of occlusive is required; Contraindicated for intertriginous and moisture bearing areas	To be used in intertriginous areas, easily absorbed, high acceptability for face, non comedogenic

O/W, oil in water; W/O, water in oil