Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Aug 27;13(9):1351.
doi: 10.3390/pharmaceutics13091351.

Viscoelastic and Deformation Characteristics of Structurally Different Commercial Topical Systems

Maryam Dabbaghi  1 , Sarika Namjoshi  1 , Bhavesh Panchal  1 , Jeffrey E Grice  1 , Sangeeta Prakash  2 , Michael Stephen Roberts  1   3   4 , Yousuf Mohammed  1
Affiliations

Viscoelastic and Deformation Characteristics of Structurally Different Commercial Topical Systems

Maryam Dabbaghi et al. Pharmaceutics. .

Abstract

Rheological characteristics and shear response have potential implication in defining the pharmaceutical equivalence, therapeutic equivalence, and perceptive equivalence of commercial topical products. Three creams (C1 and C3 as oil-in-water and C2 as water-in-oil emulsions), and two gels (G1 and G2 carbomer-based) were characterized using the dynamic range of controlled shear in steady-state flow and oscillatory modes. All products, other than C3, met the Critical Quality Attribute criteria for high zero-shear viscosity (η0) of 2.6 × 104 to 1.5 × 105 Pa∙s and yield stress (τ0) of 55 to 277 Pa. C3 exhibited a smaller linear viscoelastic region and lower η0 (2547 Pa∙s) and τ0 (2 Pa), consistent with lotion-like behavior. All dose forms showed viscoelastic solid behavior having a storage modulus (G') higher than the loss modulus (G″) in the linear viscoelastic region. However, the transition of G' > G″ to G″ > G' during the continual strain increment was more rapid for the creams, elucidating a relatively brittle deformation, whereas these transitions in gels were more prolonged, consistent with a gradual disentanglement of the polymer network. In conclusion, these analyses not only ensure quality and stability, but also enable the microstructure to be characterized as being flexible (gels) or inelastic (creams).

Keywords: critical quality attributes (CQAs); deformation characteristics; power-law functions; rheology; topical semisolid products; viscoelastic properties.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Viscosity flow sweep curves of cream (a) and gel (b) samples as a function of controlled shear stress. Reference lines from left to right are placed at 1, 10, 80, 100, and 350 Pa in ‘plot a’ and at 10, 100, and 350 Pa in ‘plot b’.
Figure 2
Figure 2
Experimental (measured) viscosity flow curves fitted to Ostwald or power-law model (a) and Carreau model (b).
Figure 3
Figure 3
Elastic modulus (G′) and viscous modulus (G″) curves of cream (a) and gel (b) samples at controlled shear strain. G′ and loss tangent (tanδ) curves of cream (c) and gel (d) samples as a function of shear stress. Horizonal reference lines in ‘plot c’ and ‘plot d’ are placed at 1 tanδ.
See this image and copyright information in PMC

References

    1. Buhse L., Kolinski R., Westenberger B., Wokovich A., Spencer J., Chen C.W., Turujman S., Gautam-Basak M., Kang G.J., Kibbe A., et al. Topical drug classification. Int. J. Pharm. 2005;295:101–112. doi: 10.1016/j.ijpharm.2005.01.032. - DOI - PubMed
    1. Shah V.P., Yacobi A., Rădulescu F.Ş., Miron D.S., Lane M.E. A science based approach to topical drug classification system (TCS) Int. J. Pharm. 2015;491:21–25. doi: 10.1016/j.ijpharm.2015.06.011. - DOI - PubMed
    1. Ethier A., Bansal P., Baxter J., Langley N., Richardson N., Patel A.M. The role of excipients in the microstructure of Topical semisolid drug products. In: Langley N., Michniak-Kohn B., Osborne D.W., editors. The Role of Microstructure in Topical Drug Product Development. Volume 36. Springer; Cham, Switzerland: 2019. pp. 155–193.
    1. Namjoshi S., Dabbaghi M., Roberts M.S., Grice J.E., Mohammed Y. Quality by Design: Development of the Quality Target Product Profile (QTPP) for Semisolid Topical Products. Pharmaceutics. 2020;12:287. doi: 10.3390/pharmaceutics12030287. - DOI - PMC - PubMed
    1. U.S. Food and Drug Administration Draft Guidance on Acyclovir. In Guidance for Industry ANDA Submissions. December 2016. [(accessed on 29 June 2021)]; Available online: https://www.accessdata.fda.gov/drugsatfda_docs/psg/Acyclovir_topical%20c....

LinkOut - more resources