Gels containing lactic acid complexed with chitosan at a stechiometric ratio 1:1 and 2:1 and 5-25% content of PEG-200 reveal pH from 3.42 to 4.95. The addition of 20 – 25% poloxamer 407 increases the pH from 4.55 to 5.30 for 1:1 gels and from 4.00 to 4.85 for 2:1 gels. The addition of 0.5% polyvinyl alcohol decreases the pH of the investigated gels from 4.00 to 4.55 for 1:1 gels and from 3.85 to 4.40 for 2:1 gels. The addition of poloxamer 407 at concentrations of 20 to 25% increases the dynamic viscosity from 506.14 to 641.20 for 1:1 and from 540.35 to 692.55 for 2:1 ratios. The addition of 0.5% polyvinyl alcohol increases the dynamic viscosity from 590.20 to 720.63 for 1:1 and from 560.90 to 698.82 for 2:1 ratios. The addition of polyvinyl alcohol and auxiliary substances reduces the pH and maintains high adhesion.
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In this paper, authors have studied the effect of the mechanics treatments parameters at high speed shifting conditions on the structural and rheological properties of aqueous solutions of hydroxypropylcellulose, polyvinyl alcohol and their mixtures.
Gels containing lactic acid complexed with chitosan at a stoichiometric ratio 1:1 and 2:1 and 5 - 25% content of polyoxyethylene glycol 200 reveal pH from 2.5 to 4.6. The addition of 20 – 25% poloxamer 407 increases the pH to 4.55 to 5.30 for 1:1 gels and 4.00 to 4.85 for 2:1 gels. The addition of 0.5% polyvinyl alcohol decreases the pH of the investigated gels to 4.00 to 4.55 for 1:1 gels and 3.85 to 4.40 for 2:1 gels. The addition of 1.0% dextrane decreases the pH of investigated gels to 4.40 to 4.90 (1:1) and 4.00 to 4.48 (2:1). Rheological investigations revealed an increase in the dynamic viscosity of preparations containing poloxamer 407 with the addition of polyvinyl alcohol or dextrane in comparison to the reference gels. Results obtained in the experimental studies proved that it is possible to produce a preparation with optimal pharmaceutical and application properties.
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Hydrogels are cross-linked hydrophilic polymer networks that find application in biomedical and pharmaceutical industries due to their unique properties. Polyvinyl alcohol is a synthetic polymer, potential biomaterial blended with various materials and compounds, that can provide new options for drug delivery systems. Determination of photochemical properties of naproxen and tryptophan immobilized in polyvinyl alcohol and two other media: water and cyclohexane was performed using UV-Vis absorption and fluorescence methods. The influences of the media used on the spectral properties of naproxen and tryptophan have been shown.
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