Hydroxypropyl-β-cyclodextrin can be abbreviated as HPCD. it is in the form of a white powder and has good solubility in water and can be dissolved in 50% ethanol and methanol. It has some relative hygroscopicity. HPCD is not irritating to muscles and is an ideal solubilizer and drug excipient for injection.
Synthesis
The most common method for the preparation of HPCD is the condensation reaction between β-cyclodextrin and propylene oxide under basic conditions, and the product is obtained by concentration and drying.
Characterisitic
The introduction of hydroxypropyl breaks the intramolecular cyclic hydrogen bond of β-cyclodextrin, which overcomes the main drawback of poor water solubility of β-cyclodextrin while maintaining the cavity of cyclodextrin. It is one of the most intensively researched and widely used cyclodextrin derivatives. It is mainly used in food, pharmaceutical and cosmetic industries.
Application
- Food and Flavors
HPCD can improve the stability and longevity of nutritional molecules, can mask or correct the bad odor and taste of food nutritional molecules, and can improve the production process and product quality.
- Cosmetics
HPCD can be used as stabilizer, emulsifier and deodorizer in cosmetic raw materials, which can decrease the irritation of organic molecules in cosmetics to skin and mucous membrane tissues, enhance the stability of active ingredients and prevent the volatilization and oxidation of nutrients. It has certain relative hygroscopicity.
- Pharmaceuticals
HPCD is an ideal solubilizer and drug excipient for injection because of its relatively low relative surface activity and hemolytic activity and lack of irritation to muscles. It can improve the water solubility of insoluble drugs, increase the stability of drugs and improve the bioavailability of drugs to increase the efficacy of pharmaceuticals. And HPCD can adjust the release rate of drugs to reduce the toxic side effects of drugs. In addition, it should pay attention to studies have reported that cyclodextrins have broad promise in the treatment of neurodegenerative diseases, such as Alzheimer’s disease (AD) and Niemann-Pick Type C disease (NPC).
- Alzheimer’s disease
Amyloid deposits of misfolded amyloid-β protein (Aβ) on neuronal cells are a pathological hallmark of Alzheimer’s disease. It has been reported the inhibitory activity of 2-Hydroxypropyl-β-cyclodextrin, as a potential sugar-based Aβ inhibitor, against Aβ1-42 aggregation and Aβ-induced toxicity. Research showed that HPCD molecules were not only nontoxic to cells, but also greatly inhibited Aβ fibrillization and reduced Aβ-induced toxicity in a concentration-dependent manner. And the inner hydrophobic cavity of HPCD was identified as a key active site for Aβ inhibition.
- Niemann-Pick Type C disease
2-hydroxypropyl-β-cyclodextrin could be useful for treating Niemann-Pick Type C disease through studies in mice. The lysosomal storage disease results from mutations in either NPC1 or NPC2 that cause cholesterol accumulation in lysosomes, leading to progressive liver disease and neurodegeneration. In mice lacking npc1, a single dose of HPCD at seven days of age caused sequestered cholesterol to flow from the lysosomes to the cytosolic compartment in a variety of organs, leading to decreased expression of proinflammatory proteins in the brain and liver compared with what was seen in untreated mice.