Microencapsulation in cosmetics
- The cosmetics and personal care industries rely heavily on delivery systems and microcapsules. They provide an ideal and one-of-a-kind carrier system for active ingredients, making it possible to release, isolate, and protect active ingredients, making the formulations more viable, masking undesirable aspects like the smell and enhancing the properties and appearance of the product.
- Microencapsulation can be used to formulate shower and shower gels, moisturisers and creams, hair care products, sunscreens and tanning creams, cosmetics, fragrances, cleansers and exfoliants [3].
Figure 2: Schematic diagram of the encapsulation process [3]
Encapsulating materials for cosmetic applications
- The core material encapsulated is the active ingredient to be used, and the material depends on the final cosmetic product where the capsules will be incorporated and the desired function.
- Other factors considered for choosing an encapsulation material are chemical and physical stability, mechanism of release of the active ingredient, concentration and particle size.
- Toxicity, biocompatibility, stability, viscosity, and mechanical properties, compatibility between the active ingredient and the wall material, the release of the active ingredient into the skin from the vehicle, enhancement of active penetration into the stratum corneum, intended particle size and microscopic properties of the surface of the microparticles, as well as the processing and economic factors, should all be taken into consideration when selecting a wall material for use in topical applications.
- The right decision of the shell material is fundamental as it impacts the efficacy and protection of the microcapsules.
- Commonly used core materials in cosmetic products for topical application have been reviewed. Encapsulating materials can be chosen from biodegradable and non-biodegradable polymers. Extensive research has been conducted on protecting active agents in micro-sized carriers for controlled release over time.
- Natural and biodegradable biopolymers like chitosan are preferred as encapsulating materials. When in contact with human tissues, these natural materials are non-toxic, non-reactive, and can be broken down, metabolised, and eliminated. Other polymers studied include aliphatic polyesters like poly(lactic acid) (PLA), and copolymers of lactic and glycolic acids like PLGA (poly(lactic-co-glycolic acid)) are the encapsulating materials that are more popular for use in skin delivery systems.
- However, the structure of chitosan can be altered to produce water-soluble chitosan, which is easily soluble in neutral aqueous solutions and expands the compound’s application range[4].