Definition of Lipsticks
Lipsticks are solid, wax-based products intended to color and protect the lips.
The primary objectives in formulating lipsticks are:
Color payoff: Deliver vibrant, even coloration.
Texture: Ensure a smooth and uniform application.
Stability: Maintain structure under different temperature conditions.
Safety: Use ingredients that are non-irritating when applied to the lips.
Key Ingredients
Waxes: Provide structure and firmness (e.g., carnauba wax, beeswax, candelilla wax).
Oils: Add gloss and spreadability (e.g., castor oil, mineral oil, lanolin).
Pigments: Provide color (e.g., iron oxides, organic pigments).
Preservatives and antioxidants: Ensure product stability (e.g., tocopherol, BHT).
Fragrance: For aesthetic appeal.
Formulation and Preparation
Melting and Mixing (Oil Phase & Wax Phase)
Waxes are heated to their melting point.
Oils, butters, and other oil-soluble ingredients are added and mixed until homogenous.
Color Dispersion
Pigments are ground or milled (e.g., three-roll mill) with a portion of the oil to reduce particle size and ensure uniform distribution.
This pigment–oil mixture is then added to the melted wax phase under constant stirring.
Cooling and Homogenization
The mixture is cooled slightly to allow partial solidification.
Thorough stirring ensures that pigments remain uniformly dispersed.
Molding
The cooled, semi-solid lipstick mass is poured into lipstick molds (often metal or silicone).
The lipstick is left to solidify (sometimes in a cooling tunnel), then removed from the molds.
Flaming and Finishing
The lipstick is passed through a gentle flame to create a glossy surface and remove surface imperfections.
Final lipsticks are inserted into their cases or tubes.