RT Journal Article
SR Electronic
T1 Thermosensitive Drug Permeation through Liquid Crystal-Embedded Cellulose Nitrate Membranes
JF PDA Journal of Pharmaceutical Science and Technology
JO PDA J Pharm Sci Technol
FD Parenteral Drug Association (PDA)
SP 54
OP 62
VO 64
IS 1
A1 Afrouz Yousefi
A1 Elham Khodaverdi
A1 Fatemeh Atyabi
A1 Rassoul Dinarvand
YR 2010
UL http://journal.pda.org/content/64/1/54.abstract
AB In this study, the application of thermotropic liquid crystals embedded in cellulose nitrate membranes as on-off drug permeation control in response to temperature changes is described. Two low-molecular-weight liquid crystals, n-pentyl-cyanobiphenyl (K15) and n-heptyl-cyanobiphenyl (K21), with nematic-to-isotropic phase transition temperatures (Tn-i) of 36.3 °C and 43.3 °C, respectively, were used to modulate drug permeation through the membrane. Liquid crystal-embedded membranes composed of appropriate blends of K15 and K21 were prepared by vacuum filtration. The permeation of pyrazinamide and metronidazole as drug models with different hydrophilicity and molecular weights through the liquid crystal-embedded membrane was examined. It was found that the drug permeation through the membrane could be modulated by changing the temperature below and above the Tn-i of liquid crystals. The permeation of pyrazinamide, the hydrophilic drug with smaller molecular weight, was more temperature-dependent than metronidazole, the hydrophobic drug with higher molecular weight. These experiments were also repeated with thermal cycling between 25 °C and 45 °C. The permeation profiles were reversible and followed zero-order kinetics.© PDA, Inc. 2010