Search

Alkyl, aryl, and alkynyl as well as heteroatom derivatives of sym-pentasubstituted corannulenes have been synthesized from sym-pentachlorocorannulene. These units form potential building blocks for future work on superstructures based on corannulene. Absorption/emission properties follow expected trends from the parent 1. sym-Pentasubstitution gives rise to variations in the chemical dynamics of bowl inversion. van der Waals attraction is cited to explain an anomalously high barrier to bowl inversion in 10.

For a series of bases, which penetrate through human skin in vitro at similar rates (0.056-0.49 microM/cm2/hr), penetrant pKa is shown to correlate with erythema, edema, and color meter readings. As estimates of irritation, erythema, edema, and redness measurements are highly linearly correlated. For the selected series, irritation becomes significant for bases with a pKa greater than 8. The irritation potential of acids with pKa less than or equal to 4 has been previously reported; pKa appears highly predictive of acute skin irritation for acids and bases in man.

The solution properties of aqueous ethanol donor solutions were characterized for the particular case of an increased flux nitroglycerin transdermal system. Permeation through porous and nonporous polymer membranes was investigated and modelled. While the permeation of ethanol through the porous membranes is adequately described by theory, clogging of pores occurs in the presence of lactose. Permeation through ethylene vinyl acetate membranes reflects interactions of the solute and solvent with the polymer.

An optimal concentration range of aqueous ethanol produces 5-10-fold increases in nitroglycerin flux across skin and ethanol skin permeation that are far greater than reported previously. For aqueous ethanol solutions saturated with nitroglycerin with an ethanol volume fraction less than or equal to 0.7, the flux of nitroglycerin across skin is linear with the ethanol flux and is traced to a linear solubility relationship and a constant diffusion coefficient.