Preparation and characterization of bioadhesive systems containing propolis or sildenafil for dental pulp protection

Abstract

Purpose: Binary polymeric systems containing poloxamer 407 (P407) and Carbopol 934P (C934P) were designed to deliver propolis extract (PE) or sildenafil citrate for the endodontic treatment (pulp protection).

Methods: Gelation temperature, rheology (flow), bioadhesion, and in vitro drug release of formulations were determined.

Results: Formulations showed thermoresponsive behavior, existing as a liquid at room temperature and gel at 34–37°C. In addition, they exhibited pseudoplastic flow and low degrees of thixotropy or rheopexy. The greatest bioadhesion was noted in the formulation containing 20% P407 (w/w) and 0.10% C934P (w/w). PE release from formulation containing 15% P407 (w/w) and 0.25% C934P (w/w) was controlled by the phenomenon of relaxation of polymer chains. Moreover, sildenafil release from formulation containing 20% P407 (w/w) and 0.10% C934P (w/w) was controlled by Fickian diffusion.

Conclusion: The data obtained on these formulations indicate a potentially useful role in the endodontic treatment (pulp protection) and suggest they are worthy of clinical evaluation.

Keywords::

• Biodegradable polymers
• buccal
• formulation
• hydrogels
• in vitro models
• mechanical properties
• natural products
• polymeric drug delivery systems
• viscosity

Acknowledgements

The authors wish to thank CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), CNPq (Conselho Nacional de Pesquisa) and FINEP (Financiadora de Estudos e Projetos) of Brazil.

Declaration of interest

The authors report no declarations of interest.