Octanol
Octanol is a straight chain fatty alcohol with eight carbon atoms and the molecular formula CH3(CH2)7OH. Although the term octanol usually refers exclusively to the primary alcohol 1-octanol, there are other less common isomers of octanol such as the secondary alcohols 2-octanol, 3-octanol and 4-octanol.
Octanol occurs naturally in the form of esters in some essential oils. The primary use of octanol is in the manufacture of various esters (both synthetic and naturally occurring), such as octyl acetate, which are used in perfumery and flavors. Other uses include experimental medical applications utilizing octanol to control certain types of involuntary tremors.[1]
Water/ octanol partitioning
Octanol and water are immiscible. The distribution of a compound between water and octanol is used to calculate the partition coefficient 'P' of that molecule (often expressed as its logarithm to the base 10, log P). Water/ octanol partitioning is a good approximation of the partitioning between the cytosol and lipid membranes of living systems.[citation needed]
Many dermal absorption models consider the stratum corneum/ water partition coefficient to be well approximated by a function of the water/ octanol partition coefficient of the form [2]:
- <math>\log(K_{sc/w}) = a + b\log(K_{w/o})</math>
Where a and b are constants,<math>K_{sc/w}</math> is the stratum corneum/ water partition coefficient, and<math>K_{o/w}</math> is the water/ octanol partition coefficient. The values of a and b vary between papers, but Cleek & Bunge [3] have reported the values a=0, b=0.74.
References
- ↑ Clinical trial number NCT00102596 at ClinicalTrials.gov
- ↑ McCarley KD, Bunge AL (2001). "Pharmacokinetic Models of Dermal Absorption". Journal of Pharmaceutical Sciences. 90 (11): 1699–1719. PMID 11745728.
- ↑ Cleek RL, Bunge AL (1993). "A new method for estimating dermal absorption from chemical exposure. 1. General approach". Pharmaceutical Research. 10 (4): 497–506. PMID 8483831.