Inhibiting Sublimation of Thymol by Cocrystallization

J Pharm Sci. 2023 Jan;112(1):350-353. doi: 10.1016/j.xphs.2022.10.019. Epub 2022 Oct 22.

Abstract

A thymol:4,4'-dipyridyl (2:1) cocrystal (Form I) is reported to suppress thymol sublimation. The cocrystal was prepared via solution-mediated phase transformation and its structure is sustained by O-H (phenol) ··· N (pyridyl) hydrogen bonds between two individual components. A cocrystal polymorph (Form II) was formed via solid state transformation or via vapor phase upon heating. Using gravimetry analysis, it was demonstrated that cocrystal Form I decreased the sublimation rate of thymol by 38-fold. This study demonstrates that cocrystallization is an effective approach to reduce vapor pressure and sublimation of solids, thus achieving odor-masking.

Keywords: Cocrystal; Dipyridyl; Polymorphism; Sublimation; Thymol.

MeSH terms

  • Crystallization
  • Hydrogen Bonding
  • Thymol*

Substances

  • Thymol