2022 Volume 22 Issue 11 Pages 551-554
Thermosensitive gels can alter their shape, strength, or physicochemical properties in response to the change in temperature. One of thermosensitive gels is stearyl acrylate (SA) organogel swollen with oil or organic solvent. There is also a copolymer hydrogel with SA and a hydrophilic monomer. These gels are synthesized by a free radical polymerization. These gels show similar thermosensitive properties such as a hard-to-soft transition and a shape-memory function. Thermosensitive properties occur on the basis that the hydrophobic stearyl side chains form a crystalline lamellar structure at temperatures below the crystallization temperature and their packing becomes amorphous at temperature above the melting temperature. The pulsatile (on-off) drug release using the SA organogel was successfully conducted: release was halted at 36°C and release occurred at over approximately 40°C.
