Abstract: A compound having the formula: ##STR1## wherein R, R.sub.1 and R.sub.2 are independently selected from hydrogen; hydroxy; fluorine; bromine; chlorine; C.sub.1 -C.sub.20 alkyl; C.sub.2 -C.sub.20 alkenyl; C.sub.2 -C.sub.20 alkynyl; C.sub.3 -C.sub.10 cycloalkyl; C.sub.2 -C.sub.20 (monohydroxy or polyhydroxy)alkyl; C.sub.1 -C.sub.20 (monohalo or polyhalo)alkyl; carboxy; C.sub.1 -C.sub.20 alkylcarboxy; C.sub.1 -C.sub.20 alkenylcarboxy; C.sub.1 -C.sub.20 carboxyalkyl; C.sub.1 -C.sub.20 alkanoyl; C.sub.1 -C.sub.20 alkanoyloxy; C.sub.1 -C.sub.20 alkoxycarbonyl; carbamoyl; carbamyl; C.sub.1 -C.sub.20 alkylcarbamyl; sulfo; C.sub.1 -C.sub.20 alkylsulfonyl; C.sub.1 -C.sub.20 alkylsulfinyl; C.sub.1 -C.sub.20 alkylsulfoxide; C.sub.1 -C.sub.20 alkylsulfone; thio; C.sub.1 -C.sub.20 alkylthio; amino; nitro; C.sub.1 -C.sub.20 alkylamino; C.sub.1 -C.sub.20 aminoalkyl; substituted or unsubstituted phenyl or benzyl, the substituents being selected from hydroxy, fluorine, bromine, chlorine, C.sub.1 -C.sub.20 alkyl, C.sub.2 -C.sub.

Abstract: Provided is a novel barrier membrane and a method using the barrier membrane for testing the transdermal penetration behavior of a bioactive agent. The method employs shed snake skin as the model barrier membrane. In particular, the method comprises the steps of providing a dose of a donor formulation containing the bioactive agent, and a receptor solution, with a barrier membrane of shed snake skin separating the donor formulation and receptor solution. The receptor solution is then serially sampled and assayed in order to determine the concentration of the bioactive agent in the receptor solution. The use of the shed snake skin has been found to provide reproducible and uniform results as a model barrier membrane. As well, the shed snake skin offers the advantages of being readily available and storable for an extended period of time.

Abstract: A diffusion cell for use in determining the absorption rate of a study substance through a permeable membrane. The cell includes a receptor chamber which contains receptor fluid to receive study substance absorbed through the membrane. The receptor chamber includes a fluid inlet and a fluid outlet. A rotary stirrer is situated adjacent the fluid outlet. The stirrer is rotated so as to rotate the receptor fluid in the receptor chamber in such manner that the fluid pressure is greater at the outlet than at the inlet, so that the stirrer defines a pump which pumps receptor fluid outwardly through the outlet, then through a detector, and then back into the receptor chamber through the inlet. The detector determines the concentration of study substance within the receptor fluid.