Topical Cream-Based Dosage Forms of the Macrocyclic Drug Delivery Vehicle Cucurbit[6]uril

Abstract

The macrocycle family of molecules called cucurbit[n]urils are potential drug delivery vehicles as they are able to form host-guest complexes with many different classes of drugs. This study aimed to examine the utility of Cucurbit[6]uril (CB[6]) in topical cream-based formulations for either localised treatment or for transdermal delivery. Cucurbit[6]uril was formulated into both buffered cream aqueous- and oily cream-based dosage forms. The solid state interaction of CB[6] with other excipients was studied by differential scanning calorimetry and the macrocycle's transdermal permeability was determined using rat skin. Significant solid state interactions were observed between CB[6] and the other dosage form excipients. At concentrations up to 32% w/w the buffered aqueous cream maintained its normal consistency and could be effectively applied to skin, but the oily cream was too stiff and is not suitable as a dosage form. Cucurbit[6]uril does not permeate through skin; as such, the results imply that cucurbituril-based topical creams may potentially only have applications for localised skin treatment and not for transdermal drug delivery.

The state-of-play and future of platinum drugs

“…While not highly soluble in pure water, they become soluble upon forming host-guest complexes with drugs and in solutions with high salt concentrations, such as blood serum, and gastric and nasal fluids (Walker et al 2011). Cucurbit[n]urils are relatively non-toxic (Oun et al 2014) and to date have been formulated into oral tablets, topical creams and eye drop solutions , Chu et al 2014, Seif et al 2014. For drug delivery the homologues of six, seven and eight subunits are of most importance as these have a cavity that is ideally sized to store and release platins.…”

Co-grinding Effect on Crystalline Zaltoprofen with β-cyclodextrin/Cucurbit[7]uril in Tablet Formulation

“…To our best knowledge, reports discussing the dosage forms of CB[ n ]s are limited, except for Wheate et al . who have investigated five different dosage forms: CB[6] in oral solid tablet14, CB[6] in topical cream15, CB[6,7,8]s in eye drop16, CB[7] in implantable hydrogel17 and CB[6,7]s in nasal insert18. Although CB[7] and β-CD exhibit similar cavity size, water solubility, and low toxicity192021, they manifest different inclusion behaviors because of their structural distinctions22.…”

Cucurbit[n]urils as excipients in pharmaceutical dosage forms

“…The solid state interactions of CB[6] with different excipients have been examined using DSC in a number of studies (33,34). An interaction is generally determined by a change in the melting point of one or both of the excipients.…”