Oxygen diffusion coefficients in commonly used topical semisolid creams.
The objective of this paper is to determine oxygen diffusion coefficients, permeabilities, and solubilities in a commonly used o/w topical ointment (similar to USP XXI hydrophilic ointment) and four commercial 1% anthralin creams. A new method developed by Ju and Ho in 1986 by applying a coupled steady-state and unsteady-state analysis for oxygen diffusion through a thin layer of test material on the surface of a membrane-covered polarographic oxygen electrode was used in the study. The results indicate that oxygen diffusion coefficients decrease with an increasing petrolatum concentration in o/w topical creams. The oxygen diffusion coefficients in four commercial creams containing 1% of extremely oxygen-sensitive anthralin were also determined using the same method. The information generated in this study can lead to a better understanding of the diffusion transport mechanism of oxygen in the topical creams and, thus, be useful to the formulation design of oxygen-sensitive drugs in semisolid dosage forms intended for topical, ophthalmic, and parenteral use.
Wang
J C
JC
Pharmaceutical Research & Development Division, Bristol-Myers Co., Buffalo, New York 14213.
Ju
L K
LK
Ho
C S
CS
D000287:Administration, Topical; D004058:Diffusion; D004566:Electrodes; D008433:Mathematics; D009824:Ointments; D010100:Oxygen; D010539:Permeability; D012995:Solubility
D009824:Ointments; D010100:Oxygen