That is, it contains small molecules that enter cells and serve as a molecular scaffolding in order to cause otherwise-misfolded mutant proteins to fold and route correctly within the cell.
Misfolded proteins are usually recognized by the quality-control system of the cell and retained (and often destroyed or recycled) in the endoplasmic reticulum.
[1] Pharmacoperones correct the folding of misfolded proteins, allowing them to pass through the cell's quality-control system and become correctly routed.
Since mutations often cause disease by causing misfolding and misrouting, pharmacoperones are potentially therapeutic agents, since they are able to correct this defect.
[1] Diseases that may be susceptible to such treatments include diabetes, inherited cataracts and cystic fibrosis.