Mucoadhesive Polymeric Polyologels Designed for the Treatment of Periodontal and Related Diseases of the Oral Cavity

Abstract

The study objective was to design and characterise herein unreported polyologels composed of a range of diol and triol solvents and polyvinyl methyl ether-co-maleic acid (PVM/MA) and, determine their potential suitability for the treatment of periodontal and related diseases in the oral cavity using suitable in vitro methodologies. Polyologel flow and viscoelastic properties were controlled by the choice of solvent and the concentration of polymer. At equivalent polymer concentrations, polyologels prepared with glycerol (a triol) exhibited the greatest elasticity and resistance to deformation. Within the diol solvents (PEG 400, pentane 1,5-diol, propane 1,2-diol, propane 1,3-diol, and ethylene glycol), PEG 400 polyologels possessed the greatest elasticity and resistance to deformation, suggesting the importance of distance of separation between the diol groups. Using Raman spectroscopy bond formation between the polymer carbonyl group and the diol hydroxyl groups was observed. Polyologel mucoadhesion was influenced by viscoelasticity; maximum mucoadhesion was shown by glycerol polyologels at the highest polymer concentration (20% w/w). Similarly, the choice of solvent and concentration of PVM/MA affected the release of tetracycline from the polyologels. The controlled release of tetracycline for at least 10 h was observed for several polyologels, which, in combination with their excellent mucoadhesion and flow properties, offer possibilities for the clinical use of these systems to treat diseases within the oral cavity.

Keywords: Raman spectroscopy; drug release; flow rheology; mucoadhesion; oscillatory analysis; polyologel.

Figure 1

Raman spectra of polyologels composed of propylene 1,2 diol (a), PEG 400 (b), glycerol (c), PVM/MA (5–20% w/w), and anhydrous PVM/MA (as a control).

Figure 2

Raman spectra of polyologels composed of diol solvents and PVM/MA (20% w/w), aqueous PVM/MA (20% w/w) gels, and anhydrous PVM/MA (as a control).

Figure 3

The mean (±s.d.) storage modules of polyologels containing PVM/MA 5% w/w (closed circles), 10% w/w (open circles), 15% w/w (closed squares), and 20% w/w (open squares), and ethylene glycol (a), propane 1,2-diol (b), propane 1,3-diol (c), pentane 1,5-diol (d), PEG 400 (e), or glycerol (f).

Figure 4

The mean (± s.d.) storage modules of polyologels containing PVM/MA 5% w/w (circles), 10% w/w (squares), 15% w/w (upward triangles), and 20% w/w (downward triangles). Open symbols refer to polyologels loaded with 1% w/w tetracycline (as the hydrochloride,) whereas close symbols refer to polyologels loaded with 5% w/w tetracycline (as the hydrochloride). (a–c) refer to polyologels prepared using propylene glycol, PEG 400, and glycerol, respectively.

Figure 5

The release of tetracycline from polyologels composed of PVM/MA (10, 15, and 20% w/w) and propylene glycol (a), PEG 400 (b), and glycerol (c). Symbols: closed and open symbols refer to 1% w/w and 5% w/w tetracycline loading (as the hydrochloride), whereas circles, squares, and triangles refer to 10% w/w, 15% w/w, and 20% w/w PVM/MA.