Chitosan in the prescription of anti-inflammatory ointments with ketoprofen
Katedra Farmacji Stosowanej Uniwersytetu Medycznego w Łodzi
Introduction. Specific properties of chitosan such as: bioactivity, biodegradability, bacteriostaticity together with safe toxicologic profile make this polymer a valuable vehicle used in medicine, pharmacy and cosmetology. The aim of the study was to design a prescription for stable anti-inflammatory ointments with chitosan, as well as to test their physicochemical properties and to estimate therapeutic agent (ketoprofen) pharmaceutical availability.
Material and methods. There were prepared two prescriptions of ointments with chitosan from shrimp shells (SD=90%). The ointment vehicle P1 was made on lanolin base, whereas in ointment vehicle P2 part of lanolin was substituted for eucerine. On the basis of the suggested vehicles preparations were manufactured with 5% ketoprofen content. The rate of volatile components loss from the tested vehicles and preparations was established with gravimetric method, while viscosity parameters were determined with cone-plate digital rheometer. Potentiometric method was applied to measure pH of the produced ointments. The test for ketoprofen pharmaceutical availability was performed with spectrophotometric method.
Results. Viscosity tests demonstrated that the produced vehicles and preparations with ketoprofen are viscoelastic systems having yield stress. Formulation F2, in which part of lanolin was substituted for eucerine, was characterised by higher extensibility and lower viscosity parameters. The results of the measurement of water loss pointed to the possibility of the increase of structural viscosity of F1 formulation during exposure and thus to the decrease of ketoprofen pharmaceutical availability. All the suggested vehicles and formulations had pH compatible with human skin pH. The tests of ketoprofen pharmaceutical availability from model preparations confirmed the results of rheological tests: the process of ketoprofen diffusion to acceptor fluid was most effective from F2 formulation.
Conclusion. The produced prescriptions of ointment with chitosan are characterised by high ketoprofen pharmaceutical availability.
Key words: anti-inflammatory ointments, skin, chitosan, ketoprofen, rheological parameters, pharmaceutical availability