Hydrophobic propofol

Propofol is properly named 2,6-diisoproplylphenol. Because there are 12 carbon atoms, this compound is not very soluble in water, and it is much more soluble in hydrophobic solvents. Therefore propofol is formulated as an emulsion2 of the 2,6-diisoproplylphenol suspended in a mixture of soybean oil and water. An egg-based phospholipid (e.g., lecithin) is added to stabilize the emulsion. By the way, you can buy flavored water-soybean oil-lecithin mixtures, but you call it mayonnaise. 

In eight subjects the concentration of remifentanil was significantly increased when therapeutic concentrations of propofol were present in the body (41). The combination of propofol and remifentanil can cause cardiovascular depression. As with other opioids, remifentanil competes with propofol for hydrophobic binding in the lungs and heart. 

The hydrophobicity of propofol is due to the aromatic phenyl nucleus and the two isopropyl... 

Fig. 7.20 Chemical structure of propofol. The aromatic ring nucleus and two isopropyl groups give the molecule its hydrophobic properties...

Boyd has examined the delivery profile from cubosomes of various hydrophobic drugs, including griseofulvrn, rifampicin, diazepam and propofol [39]. In each case only burst release was found and the release reached a plateau within 20 min (Figure 15.6). 

The authors assumed that the partition coefficient of the lipophilic drug dictates the extent of release compared to other dmgs at the same dilution. The rank order for the extent of release for the three unionized drugs, griseoftilvin, diazepam and propofol was consistent with the octanol-water partition coefficient (log ko/w) listed in Table 15.1. It was reasonable to assume that the lower affinity of griseofulvin for the hydrophobic phase allowed the greatest extent of release, and conversely for propofol. 

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