In the molecular structure of hydroxypropyl beta cyclodextrin, hydroxyl groups are mainly distributed outside the cavity, glucoside bond oxygen atoms are located in the cavity, which makes the cavity hydrophobic, hydrophilic outside the cavity. Because of this characteristic, hydroxypropyl beta cyclodextrin has the effect of inclusion and solubilization on lipophilic drugs. It is a functional additive in the current cosmetics: flavonoids, polyphenols, vitamin E, essential oil and essence are mostly fat soluble and easy to oxidize. The inclusion of these substances with hydroxypropyl beta cyclodextrin not only ensures the stability of these substances, but also increases the solubility of these substances, thus improving the bioavailability of these active substances. For example, the water solubility of retinoic acid increased from 0.8mg/100ml to 200mg/100ml after inclusion with hydroxypropyl betacyclodextrin.
Hydroxypropyl beta cyclodextrin (HPBCD) hydrophobic cavity can encapsulate polyunsaturated fatty acids (PUFAs) exuded from the skin, prevent their oxidative deterioration, inhibit the formation of free radicals, reduce skin infection and inflammation, and prevent acne.