Fabrication of organogels achieved by prodrug-based organogelators of ketoprofen

The treatment strategy of curing diseases using prodrugs of an anti-inflammatory drug is widespread. In the present study, we report on the synthesis of prodrugs of ketoprofen, consisting of a derivatization of ketoprofen and long hydrocarbon chain of fatty acids with diacylhydrazine linkage. The presence of an acidic moiety in ketoprofen may lead to ulceration in the gastrointestinal tract that reduces the efficacy of the drug with an increased adverse effect. The synthesis of prodrugs of ketoprofen involves the use of fatty acids as a carrier and hydrazine as a spacer. Synthesized prodrugs were characterized by infrared, H-1-NMR and mass spectroscopy. The resulting prodrugs were found to be insoluble in water and precipitated out in acetonitrile, hexane, benzene, and so on. The synthesized prodrugs are slightly soluble in chloroform, methanol and ethanol and only form a gel like structure in carbon tetrachloride. The resulting gels are referred as organogels and prodrugs are referred to as organogelators. The surface morphology of the prepared organogels were studied by field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), and other spectral characteristics were also investigated. FE-SEM and TEM images revealed that there were continuous elongated fiber-like structures present that were in the nanometer size range. Gel-sol temperature profiles of the prepared organogels were also studied using differential scanning calorimetry. The results from all these techniques are presented and discussed from point of view of the use of the derivatives as prodrug formulations. It is demonstrated that the prodrug containing the diacylhydrazine moiety has the ability to form a gel.