[Binding affinity of ibuprofen in human tissues].

In vitro binding of ibuprofen (CAS 15687-27-1) to various human tissues was studied to explain differences in tissue concentration after local application of ibuprofen cream. Radioactive ibuprofen, was incubated with human skin, subcutaneous tissue, muscle, tendon, joint capsule for 2 h at 37 degrees C. Tissue specimens were washed and radioactivity was measured by a liquid scintillation counter. The results show specific binding of ibuprofen to the various tissues of different degrees. Despite of interindividual differences muscle tissues showed the highest, tendons the lowest concentrations of ibuprofen. These findings may explain the in vivo results, where higher concentrations of ibuprofen were found in muscle tissue compared with subcutaneous tissue.