Allopurinol – β-cyclodextrin (ALP-β-CD)

Allopurinol – β-cyclodextrin is a supramolecular inclusion complex consisting of the xanthine oxidase inhibitor allopurinol and the cyclic oligosaccharide β-cyclodextrin (Source: PubMed, PMID: 11454448). This entity is not a biological target but a pharmaceutical formulation designed to enhance the solubility and bioavailability of allopurinol, which is otherwise poorly soluble in water (Source: PubChem). The β-cyclodextrin molecule features a hydrophobic interior cavity that hosts the allopurinol molecule, improving its dissolution profile in the gastrointestinal tract (Source: ScienceDirect). Upon release, allopurinol targets the enzyme xanthine oxidase, effectively blocking the production of uric acid from hypoxanthine and xanthine (Source: StatPearls). This mechanism is critical for managing hyperuricemia-related disorders, including chronic gout and uric acid nephropathy (Source: NIH). Clinical use of this complex aims to maintain serum urate levels below saturation points to prevent crystal deposition and inflammatory flares. However, clinicians must remain vigilant for severe cutaneous adverse reactions associated with the allopurinol component, particularly in patients with the HLA-B*5801 allele (Source: FDA). The complex represents an application of host-guest chemistry to improve the therapeutic index of a well-established medication.

Other names

Allopurinol/beta-cyclodextrin inclusion complexAllopurinol-beta-cyclodextrinALP-beta-CDAllopurinol-cyclodextrin complex

The complex acts as a delivery system for allopurinol; once released, allopurinol and its active metabolite oxypurinol inhibit xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and xanthine to uric acid (Source: StatPearls, 2023).