Application

The solubility of lipophilic drugs increases linearly with the concentration of hydroxypropyl-β-cyclodextrin (HBC) in aqueous solution because of the complex between HBC and the drug. This guest-host type complex is formed between the drug and the non-polar cavity in the HBC that results in enhanced solubility. Solutions may be lyophilized to produce freely soluble powders. Non-toxic in rabbits and mice.

General description

Cyclodextrins are cyclic oligosaccharides consisting of 6, 7, or 8 glucopyranose units, usually referred to as α-, β-, or γ-cyclodextrins, respectively. These compounds have rigid doughnut-shaped structures making them natural complexing agents. The unique structures of these compounds owe their stability to intramolecular hydrogen bonding between the C2- and C3-hydroxyl groups of neighboring glucopyranose units. The molecule takes on the shape of a torus with the C2- and C3-hydroxyls located around the larger opening and the more reactive C6-hydroxyl aligned around the smaller opening. The arrangement of C6-hydroxyls opposite the hydrogen bonded C2- and C3-hydroxyls forces the oxygen bonds into close proximity within the cavity, leading to an electron rich, hydrophobic interior. The size of this hydrophobic cavity is a function of the number of glucopyranose units forming the cyclodextrin.The solubility of natural cyclodextrins is very poor. In the late 1960’;s, it was discovered that chemical substitutions at the 2, 3, and 6 hydroxyl sites would greatly increase solubility. Most chemically modified cyclodextrins are able to achieve a 50% (w/v) concentration in water.Cavity size is the major determinant as to which cyclodextrin is used in complexation. The cavity diameter of β-cyclodextrins or β-glucopyranose unit compounds is well-suited for use with molecules the size of hormones, vitamins and many compounds frequently used in tissue and cell culture applications. For this reason, β-cyclodextrin is most commonly used as a complexing agent.

Packaging

5, 10 g in poly bottle

Preparation Note

Solutions may be stored for several months at 4°C. Solid should be stored tightly sealed at room temperature.