Incorporation of non-steroidal anti-inflammatory drugs into specific monophasic formulations

The presence of monophasic domains in systems made up of free unsaturated fatty acids, potassium oleate, d-limonene and transcutol was investigated to determine the possibilities of the incorporation of two anti-inflammatory drugs (piroxicam or diclofenac). The role of the unsaturation of fatty acids in obtaining suitable monophasic compositions with the additional presence of two percutaneous absorption enhancers (d-limonene and transcutol) can be noted from the results obtained. The monophasic realms visualized for the different systems studied were mainly dependent on the free fatty acid-potassium oleate combination (variable weight ratio). The final pH value of the monophasic compositions obtained was also different. Alternatively, some other interesting compounds present in the stratum corneum (i.e. glycerine or squalene) can be also used. A percutaneous absorption assay of piroxicam incorporated into two monophasic compositions was carried out as a preliminary experiment, with promising results. These systems may possibly constitute suitable drug delivery strategies for the topical application of anti-inflammatory compounds.