Cyclodextrin Derivatives

Cyclodextrin (CD), as a cheap, widely available, biocompatible and biodegradable compound, has applications in pharmaceutical and biomedicine, personal care, food and other fields ^[1]. Due to their unique molecular structures, CDs are easily modified to obtain CD derivatives. The physiochemical properties and inclusion capacity of modified CD are better than those of original CDs, making them more suitable for their intended use. A total of more than 11,000 CD derivatives are currently available on the market.

Alfa Chemistry provides a variety of industrially produced CD derivatives in bulk, including (2-hydroxypropyl)-CD, sulfobutyl ether-beta(β)-CD sodium salt, methyl-β-CD, glucosyl-β-CD, and hyperbranched CD, as listed at the top of the page. Aside from these common CD derivatives, we also provide other CD derivatives required by customers through our professional synthesis laboratory. Please refer to Custom Synthesis.

Description of Common CD Derivatives

The following is a brief introduction to three types of common CD derivatives: hydroxypropyl CDs, sulfobutyl ether CDs and methyl CDs.

• Hydroxypropyl CDs

Hydroxypropyl CDs can be classified into 2-hydroxypropyl-alpha(α)-CD, 2-hydroxypropyl-beta(β)-CD, and 2-hydroxypropyl-gamma(γ)-CD, which are hydroxyalkylated derivatives of native CDs. Due to the introduction of the hydrophilic group hydroxypropyl and the retention of the cavity in the original structure, the water solubility and selectivity for guest molecules of CD molecules are improved. Hydroxypropyl-β-CD has been used as an additive in injection preparations due to its great water solubility (>500 g/L, 20 °C) and lower hemolysis, which has been approved by the Food and Drug Administration (FDA). It is currently the most promising CD material.

• Sulfobutyl ether CDs

Sulfobutyl ether CDs are sulfonic acid-substituted derivatives of anionic highly water-soluble CDs. Taking sulfobutyl ether-β-CD as an example, the common substitution degrees are 4 and 7 in practice. Compared to β-CD, it has higher solubility, higher inclusion capacity, and is safer. Sulfobutyl ether-β-CD is mainly used as a pharmaceutical excipient, with the main functions being to improve the solubility of drugs, improve the stability of drugs, reduce the irritation of drugs, and mask bad odors. In addition, sulfobutyl ether-β-CD can also be used in targeted preparations.

• Methyl CDs

Methyl CDs are alkylated CD derivatives. After CD is methylated, the stereoselectivity of the molecule is improved. The most common methylated CD derivatives are modified based on β-CD. β-CD has seven glucose residues, and C₂, C₃, and C₆ on each glucose residue can be replaced by methyl groups. The position and number of substitutions affect crystalline morphology, water solubility, fat solubility, recognition and inclusion capabilities of guest molecules of methylated CD derivatives. Randomly methylated-β-CD has better water solubility, better inclusion ability, and better stability in acid than β-CD.

Water Solubility of Common CD Derivatives

Using β-CD as a template molecule for modification, the solubility of hydroxypropyl-β-CD, sulfobutyl ether-β-CD and methyl-β-CD was improved. Table 1 lists the solubility information for native β-CD and three common β-CD derivatives.

Table 1. Solubility of native β-CD and common β-CD derivatives ^[1].

Alfa Chemistry is one of the leading CD manufacturers. In addition to kilograms of native CDs, we also offer high-quality CD derivatives, including (2-hydroxypropyl)-CD, sulfobutyl ether-β-CD sodium salt, methyl-β-CD, glucosyl-β-CD, and hyperbranched CD, and related support to meet customers' needs. We also offer custom synthesis of other CD derivatives, committed to providing the best possible experience for our customers. For more information, please feel free to contact us.

It should be noted that our our products and services are for research use only, not for clinical use.