Rheological evaluation of petroleum jelly as a base material in ointment and cream formulations: steady shear flow behavior

Arch Pharm Res. 2010 Jan;33(1):141-50. doi: 10.1007/s12272-010-2236-4. Epub 2010 Feb 27.

Abstract

The objective of the present study is to systematically characterize a nonlinear rheological behavior of petroleum jelly (petrolatum) in steady shear flow fields correspondent to the spreading condition onto the human body. With this aim, using a strain-controlled rheometer, the steady shear flow properties of commercially available petroleum jelly have been measured at 37 degrees C (body temperature) over a wide range of shear rates. In this article, the shear rate dependence of steady shear flow behavior was reported from the experimentally obtained data. In particular, the existence of a yield stress and a non-Newtonian flow behavior were discussed in depth with a special emphasis on their importance in actual application onto the human body. In addition, several inelastic-viscoplastic flow models including a yield stress parameter were employed to make a quantitative description of the steady shear flow behavior, and then the applicability of these models was examined in detail. Main findings obtained from this study can be summarized as follows: (1) Petroleum jelly exhibits a finite magnitude of yield stress. The appearance of a yield stress is attributed to its three-dimensional network structure that can show a resistance to flow and plays an important role in determining a storage stability and sensory feature of the product. (2) Petroleum jelly demonstrates a pronounced non-Newtonian shear-thinning flow behavior which is well described by a power-law equation and may be interpreted by the disruption of a crystalline network under the influence of mechanical shear deformation. This rheological feature enhances sensory qualities of pharmaceutical and cosmetic products in which petroleum jelly is used as a base material during their actual usage. (3) The Casson, Mizrahi-Berk, Heinz-Casson and Herschel-Bulkley models are all applicable and have almost an equivalent ability to quantitatively describe the steady shear flow behavior of petroleum jelly whereas the Bingham model does not give a good validity. Among these flow models, the Herschel-Bulkley model provides the best applicability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Chemistry, Pharmaceutical
  • Cosmetics / chemistry
  • Crystallization
  • Elasticity
  • Microscopy, Electron
  • Models, Chemical
  • Ointment Bases / chemistry*
  • Paraffin / chemistry
  • Petrolatum / chemistry*
  • Rheology
  • Viscosity

Substances

  • Cosmetics
  • Ointment Bases
  • Paraffin
  • Petrolatum