Many cucurbiturils (CB[n]s) have been synthesized by the Isaacs Lab, and several featured in previous SAMPL challenges. The potential applications of cucurbiturils include use as solublizing excipients for insoluble drugs, sequestrants for drugs of abuse and neuromuscular blockers, and pH triggered delivery agents . This family of hosts typically have a molecular structure containing n glycoluril units connected via 2n methylene bridges, forming a barrel shaped macrocycle with a central hydrophobic cavity. In addition, cucurbiturils contain electrostatic carbonyls protruding out from the hydrophobic cavity.