Skip to main content
Log in

Rheological Characterization of Topical Carbomer Gels Neutralized to Different pH

  • Published:
Pharmaceutical Research Aims and scope Submit manuscript

Abstract

Purpose. The primary objective of this study is to perform detailed and extensive rheological characterization of rheology of carbomer (Carbopol) microgels formulated using a solvent system typically used in topical gel formulations. Solvents like glycerin and propylene glycol can alter rheology and drug delivery characteristics of topical gels owing to their different viscosities and due to the change in solvent-polymer and solvent-solvent interactions.

Methods. Aqueous gels with different pH were prepared by dissolving cross-linked Carbopol polymers in a co-solvent system comprising water, propylene glycol, and glycerol and subsequently neutralizing the carboxylic groups of the polymers with triethanolamine (TEA). Oscillatory, steady, and transient shear measurements were performed to measure viscoelastic properties, temperature dependency, yield strength, and thixotropy of carbomer pharmaceutical gels.

Results. The topical pharmaceutical gels exhibit remarkable temperature stability. Flow curves obtained at different temperatures indicate Carbopol microgels show much more pseudoplastic behavior (lower power law index) compared to Carbopol gels dissolved only in water. Substantial yield strength is required to break the microgel network of the topical gels. The gel samples exhibit modest thixotropy at higher deformation rates.

Conclusions. The rheological behavior of the Carbopol microgels do not change appreciably in the pH range 5.0-8.0, and the gels can be used as effective dermatological base for topical applications.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. M. Sjoberg, L. Bergstrom, A. Larsson, and E. Sjostrom. The effect of polymer and surfactant adsorption on the colloidal stability and rheology of kaolin dispersions. Colloids Surf. A, Physicochemical Eng. Asp. 159:197-208 (1999).

    Google Scholar 

  2. K. D. Bremecker, B. Koch, W. Krause, and L. Neuenroth. Application-triggered drug release from an O/W-emulsion. Pharm. Ind. 54:182-185 (1992).

    Google Scholar 

  3. J. Y. Kim, J. Y. Song, E. J. Lee, and S. K. Park. Rheological properties and microstructures of Carbopol gel network system. Colloid Polym. Sci. 281:614-623 (2003).

    Google Scholar 

  4. M. Yonese. Sustained drud delivery by gels. In Y. Osada and K. Kajiwara (eds.), Gels Handbook. Vol. 3, Academic Press, San Diego, CA, 2001, pp. 230-240.

    Google Scholar 

  5. S. Ding. Recent developments in ophthalmic drug delivery. Pharm. Sci. Tech. Today 1:328-335 (1998).

    Google Scholar 

  6. B. F. Goodrich. Polymers for pharmaceutical applications I. General overview, B. F. Goodrich, 1997.

  7. S. Tamburic and D. Q. M. Craig. Rheological evaluation of polyacrylic acid hydrogels. Pharm. Sci. 1:107-109 (1995).

    Google Scholar 

  8. S. Tamburic and D. Q. M. Craig. An investigation into the rheological, dielectric and mucoadhesive properties of poly(acrylic acid) gel systems. J. Control. Rel. 32:59-68 (1995).

    Google Scholar 

  9. M. J. C. Fresno, A. D. Ramirez, and M. M. Jimenez. Systematic study of the flow behaviour and mechanical properties of Carbopol (R) Ultrez (TM) 10 hydroalcoholic gels. Europ. J. Pharm. Biopharm. 54:329-335 (2002).

    Google Scholar 

  10. M. J. F. Contreras, A. R. Dieguez, and M. M. J. Soriano. Rheological characterization of hydroalcoholic gels-15% ethanol-of Carbopol (R) Ultrez (TM) 10. Farmaco 56:437-441 (2001).

    Google Scholar 

  11. D. M. Plaiziervercammen. Rheological Properties of Carbopol-950 and Carbopol-954 neutralized with triethanolamine and Neutrol Te. Pharmazie 46:646-650 (1991).

    Google Scholar 

  12. J. S. Chu, D. M. Yu, G. L. Amidon, N. D. Weiner, and A. H. Goldber. Viscoelastic properties of polyacrylic acid gels in mixed solvents. Pharm. Res. 9:1659-1663 (1992).

    Google Scholar 

  13. H. O. Ho, F. C. Huang, T. D. Sokoloski, and M. T. Sheu. The influence of cosolvents on the in-vitro percutaneous penetration of diclofenac sodium from a gel system. J. Pharm. Pharmacol. 46:636-642 (1994).

    Google Scholar 

  14. A. Arellano, S. Santoyo, C. Martin, and P. Ygartua. Influence of propylene glycol and isopropyl myristate on the in vitro percutaneous penetration of diclofenac sodium from carbopol gels. Euro. J. Pharm. Sci. 7:129-135 (1999).

    Google Scholar 

  15. R. J. Ketz, R. K. Prud'homme, and W. W. Graessley. Rheology of concentrated microgel solutions. Rheol. Acta. 27:531-539 (1988).

    Google Scholar 

  16. H. N. Nae and W. W. Reichert. Rheological properties of lightly crosslinked carboxy copolymers in aqueous solutions. Rheol. Acta 31:351-360 (1992).

    Google Scholar 

  17. B. Testa and J. C. Etter. Report concerning rheology used to study interactions between carbopol macromolecules as well as semiquantitative determination of ionic force of their dispersions. Pharm. Acta Helv. 6:378-388 (1973).

    Google Scholar 

  18. J. D. Ferry. Viscoelastic Properties of Polymers, 3rd Ed., Wiley, New York, 1980.

    Google Scholar 

  19. R. Barreiro-Iglesias, C. Alvarez-Lorenzo, and A. Concheiro. Incorporation of small quantities of surfactants as a way to improve the rheological and diffusional behavior of carbopol gels. J. Control. Rel. 77:59-75 (2001).

    Google Scholar 

  20. W. P. Cox and E. H. Merz. Correlation of dynamic and steady flow viscosities. J. Polym. Sci. 28:619-622 (1958).

    Google Scholar 

  21. R. G. Larson. The Structure and Rheology of Complex Fluids, Oxford University Press, New York, 1999.

    Google Scholar 

  22. H. A. Barnes. A brief history of the yield stress. Appl. Rheol. 9:262-266 (1999).

    Google Scholar 

  23. D. D. Atapattu, R. P. Chhabra, and P. H. T. Uhlherr. Wall effect for spheres falling at small reynolds-number in a viscoplastic medium. J. Non-Newtonian Fluid. Mech. 38:31-42 (1990).

    Google Scholar 

  24. Q. D. Nguyen and D. V. Boger. Yield stress measurement for concentrated suspensions. J. Rheol. 27:321-349 (1983).

    Google Scholar 

  25. R. B. Bird, R. C. Armstrong, and O. Hassager. Dynamics of Polymer Liquids, 2nd Ed., Wiley, New York, 1987.

    Google Scholar 

  26. A. Ramirez, M. J. Fresno, M. M. Jimenez, and E. Selles. Rheological study of Carbopol (R) Ultrez (TM) 10 hydroalcoholic gels, I: Flow and thixotropic behavior as a function of pH and polymer concentration. Pharmazie 54:444-447 (1999).

    Google Scholar 

  27. J. Ferguson and Z. Kemblowski. Applied Fluid Rheology, Elsevier Applied Science, London and New York, 1992, Chap. 2 and 5.

    Google Scholar 

  28. M. J. F. Contreras, A. R. Dieguez, and M. M. J. Soriano. Viscosity and temperature relationship in ethanol/water mixtures gelified with Carbopol (R) Ultrez (TM) 10. Farmaco 56:443-445 (2001).

    Google Scholar 

  29. A. Ramirez, M. J. Fresno, M. M. Jimenez, and E. Selles. Rheological study of Carbopol (R) Ultrez (TM) 10 hydroalcoholic gels, II: Thermal and mechanical properties as a function of pH and polymer concentration. Pharmazie 54:531-534 (1999).

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Chrisita Ackermann.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Islam, M.T., Rodríguez-Hornedo, N., Ciotti, S. et al. Rheological Characterization of Topical Carbomer Gels Neutralized to Different pH. Pharm Res 21, 1192–1199 (2004). https://doi.org/10.1023/B:PHAM.0000033006.11619.07

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/B:PHAM.0000033006.11619.07

Navigation