Temperature-Frequency Equivalence of the Viscoelastic Properties of Anhydrous Lanolin USP

• Published in: Journal of pharmaceutical sciences 1983-04, Vol.72 (4), p.422-425
• Main Authors: Radebaugh, Galen W., Simonelli, Anthony P.
• Format: Article
• Language: English
• Subjects: Anhydrous lanolin-viscoelastic parameter determination; Anhydrous lanolin—viscoelastic parameter determination, temperature-frequency equivalence; Biological and medical sciences; Dynamic mechanical testing-viscoelastic parameter determination for anhydrous lanolin; Dynamic mechanical testing—viscoelastic parameter determination for anhydrous lanolin, energy of activation for mechanical transitions; Elasticity; energy of activation for mechanical transitions; General pharmacology; Lanolin; Medical sciences; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Pharmacopoeias as Topic; superposition of parameters; Temperature; temperature-frequency equivalence; United States; Viscoelasticity-properties of anhydrous lanolin determined by dynamic mechanical testing; Viscoelasticity—properties of anhydrous lanolin determined by dynamic mechanical testing, temperature-frequency equivalence, superposition of parameters; Viscosity
• ISSN: 0022-3549; 1520-6017
• DOI: 10.1002/jps.2600720424

□ Methods of data analysis novel to pharmaceutical semisolids have been applied to the dynamic mechanical data obtained for anhydrous lanolin USP. It was found that the viscoelastic parameters determined over a wide range of temperatures and shear frequencies could be superposed. Elastic moduli (G′) and viscous moduli (G″) obtained at low temperatures (T) and frequencies (v), were equivalent to moduli obtained at high T and v. Empirical shifts of modulus versus shear frequency data obtained at different temperatures were used to produce G′ and G″ versus v master curves (complete log modulus versus log frequency behavior at a constant temperature). A method of reduced variables, in conjunction with an Arrhenius-type relation, proved useful in calculating the energy of activation for the structural processes involved in a major mechanical transition.