Active delivery technologies are ingredients or formulation approaches that improve stability and efficacy or reduce active irritation for consumers in a meaningful way. Typically, the best strategy is to deliver superiority for both leave-on, as well as rinse-off products, and this is the source of many personal care patent filings. In monographed OTC categories, this is the only way superiority can normally be claimed, since everyone is required to use the same actives.
8 Development Principles
- Delivery technologies need to be designed for the specific active and need. Drop-in technologies are rarely optimal.
- Actives should be high-value-added materials to justify the added cost.
- Ideally, actives should be functional at low concentrations (<1%).
- For rinse-off products, delivery technologies must both increase deposition and be functional.
- Optimize efficacy while minimizing negatives.
- Become familiar with a broad variety of delivery systems before you have a specific need.
- Develop multiple options.
- Combining different delivery approaches can often produce breakthrough results.
9 Active Delivery System Objectives
- Improved stability
a. UV – An example would be the use of Ronacare® AP (EMD) to improve the photostability of avobenzone, retinol, carotenoids, and tocopherol on skin
b. Oxygen – The use of lamellar crystalline gel network-based formulations can significantly improve the stability of retinol.
- Improved bioavailability – Using phospholipids can provide increased skin penetration while minimizing skin irritation.
- Reduced skin irritation – The use of sunscreens with encapsulated solid lipid nanoparticles can significantly reduce the skin penetration of chemical sunscreens while increasing SPF.
- Sustained release – Provide long lasting activity over time.
- Increase efficacy / reduce the amount of active needed – For example, using SPF boosters to improve SPF efficiency. The typical commercial chemical sunscreen only has an SPF efficiency of around 1.6 SPF units / 1% active. Optimized SPF boosters can double this to 3.2.
- Improved active solubility – Increasing the water solubility of actives using cyclodextrins.
- Triggered release (heat, electrolyte, water, or PH) – Sweat-activated cyclodextrin or starch-encapsulated fragrances in an antiperspirant stick can provide a freshness signal and mask malodor.
- Improved deposition (for rinse off products) and release – Micronizing actives like zinc pyrithione can significantly improve anti-dandruff efficacy.
- Reduced volatility of actives (menthol, fragrances) – Cyclodextrin complexes can significantly reduce the volatility of fragrances.
10 Types of Delivery Technologies
b. Cyclodextrin, soluble/insoluble complexes.
- Encapsulates (starch, gelatin, urea/formaldehyde)
- Absorbing/adsorbing particles (porous, hollow)
a. Microemulsions (o/w, w/o, bicontinuous)
b. Nanoemulsions (o/w, w/o)
c. Vesicular (o/w unilamellar or mutlilamellar), liposomes
d. Multiple emulsions (w/o/w, o/w/o)
e. Lamellar liquid and crystalline phases
f. Surfactant/polymer complexes
g. Micronized actives, solid lipid nano particles
- Enteric coatings
- Anionic surfactant / cationic polymer complexes
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