Formulation and evaluation of hydrogel containing dry extract of Tormentillae rhizoma designed for periodontal disease

 

According to the European Pharmacopoeia, Tormentillae rhizoma is the dried rhizome of tormentil (Potentilla erecta (L.) Raeusch, Rosaceae), freed from the roots. Tormentillae rhizoma is a traditional herbal medicinal product for symptomatic treatment of unspecified diarrhoea, mild inflammation of the oral and pharyngeal mucosa [1]. Dental plaque is a highly diverse biofilm, with an important function in maintenance of oral and systemic health. In some conditions the biofilm becomes a cause of oral diseases (e.g. periodontal disease) [2]. Current methods of dental plaque control involve the use of chemical agents against biofilm pathogens. This is not sufficiently effective [3]. Prevention and control of dental plaque might be achieved by using hydrogels containing compounds that hinder glucosyltransferase activity and extracellular polysaccharides synthesis. In this study, we formulated and performed quality evaluation of new hydrogel formulations containing dry extract of tormentil. Components of dry extract were identified and tracked by LC-TOF-MS method. The dominant compounds of tormentil rhizomes are ellagitannins (agrimoniin) and oligomeric proanthocyanidins. During preliminary studies using different types of polymers, it was shown that carmellose natrium – based hydrogel did not interact with tormentil extract and was provided optimal physico-chemical and rheological properties. Designed hydrogels containing 5 or 10 mg/g of the dry extract possessed significant mucoadhesive properties evaluated by TA.XT. Plus Texture Analyzer and three different models of adhesive layers (porcine buccal mucosa, mucin and gelatine) [4]. Their mucoadhesive properties were determined to be better than commercially available product used as a control. Hydrogels at concentrations 5 and 10 mg/g, exhibited no anti-microbial activity, but strongly inhibited extracellular polysaccharides and artificial biofilm formation. Based on viscosity and thixotropy measurements using a programmable viscometer with cone-plate device [5]., it can be concluded that hydrogels were characterized by desirable thixotropic properties both at 25^°C and 37^°C. This study reveals that designed hydrogels seem to be promising vehicles which can be used for drug delivery in periodontal disease.

Acknowledgements: The study was conducted with the use of equipment by Medical University of Bialystok as part of the OP DEP 2007 – 2013, Priority Axis I.3, contract No. POPW.01.03.00 – 20 – 001/12.

Keywords: Potentilla erecta, hydrogel, mucoadhesive properties, periodontal disease.

References:

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