98% Hydroxypropyl Beta Cyclodextrin Powder

Hydroxypropyl-β-cyclodextrin (HP-β-CD) is a derivative of β-cyclodextrin (β-CD), obtained from starch through enzymatic cyclization. It is produced by substituting β-cyclodextrin with hydroxypropyl ether under alkaline conditions, resulting in significantly enhanced water solubility (≥ 600 mg/mL).

HP-β-CD consists of seven α-pyranose glucose units, each of which can be substituted with 0 to 3 hydroxypropyl ether groups. Its unique cyclic structure features a hydrophilic outer surface and a hydrophobic inner cavity. The degree of substitution (DS) refers to the average number of hydroxypropyl groups per glucose unit, with a maximum molar substitution of 7. Each molecule may exhibit different substitution patterns.

HP-β-CD has excellent water solubility, typically exceeding 50% at room temperature, preventing crystallization in aqueous-alcoholic solutions.

Compared to β-CD, HP-β-CD exhibits different selectivity for guest molecules, potentially altering the molecular ratio in inclusion complexes.

HP-β-CD is not significantly metabolized or accumulated in the human body. When taken orally, most of it is excreted in feces, while for parenteral administration, nearly all is eliminated via urine.

Within the body, HP-β-CD helps promote the quick release of encapsulated substances.

Compared to β-CD or other derivatives (e.g., methylated β-CD), HP-β-CD has lower surface activity and hemolytic activity, making it a safer option for pharmaceutical applications.

HP-β-CD can encapsulate drug molecules, altering their crystalline structure to improve water solubility, accelerate gastrointestinal absorption, enhance efficacy, and reduce dosage. For example, the solubility of oxaprozin increases from 0.01 mg/mL to 2.599 mg/mL.

Through complexation, HP-β-CD helps protect drugs from degradation caused by light, oxidation, and heat, thereby extending their shelf life. For instance, the degradation half-life of estradiol extends from 1.2 years to 4 years.

HP-β-CD encapsulation minimizes direct contact between the drug and biological tissues, reducing adverse reactions. For example, mitomycin HP-β-CD complexes lower the risk of injection-induced skin redness and ulcers.

By adjusting the degree of substitution in HP-β-CD, different drug release profiles can be achieved, including immediate release, delayed release, extended release, and controlled release. For example, fentanyl HP-β-CD complexes enable sustained pain relief after injection.

HP-β-CD can improve drug penetration through the cornea. For example, it increases the corneal permeability of pilocarpine by nearly fourfold, enhancing the effectiveness of ophthalmic drugs.