Effect of a polyvinyl alcohol and selected auxiliary substances on the properties of thermosensitive hydrophilic gels containing lactic acid complexed with chitosan

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.