Tetanus toxoid (TTd) plays an important role in the pharmaceutical world, especially in vaccines. The toxoid is obtained after formaldehyde treatment of the tetanus toxin. In parallel, current emphasis in the drug discovery field is put on producing well-defined and safer drugs, explaining the interest in finding new alternative proteins. The tetanus toxin fragment C (TTFC) has been extensively studied both as a neuroprotective agent for central nervous system disorders owing to its neuronal properties and as a carrier protein in vaccines. Indeed, it is derived from a part of the tetanus toxin and, as such, retains its immunogenic properties without being toxic. Moreover, this fragment has been well characterized, and its entire structure is known. Here, we propose a systematic review of TTFC by providing information about its structural features, its properties and its methods of production. We also describe the large uses of TTFC in the field of drug discovery. TTFC can therefore be considered as an attractive alternative to TTd and remarkably offers a wide range of uses, including as a carrier, delivery vector, conjugate, booster, inducer, and neuroprotector.

In the process of developing bioactive small molecules, solubility determination is a crucial step. Many research papers treating problems related to solubility are published, but none of them fully describes the methods and steps for solubility assessment. In addition, in silico prediction tools and databases such as SwissADME, ACD/Percepta, DrugBank and many others offer the possibility to have approximative solubility values based on the structure of the molecule. Although significant differences can be observed depending on the database and the conditions of the experiment such as solvent, pH, temperature… etc. The lack of data can be a barrier to obtaining details on solubility measurement methods. This presentation aims to describe, step by step, the journey of tryptophan solubility determination using high-performance liquid chromatography-diode array detector (HPLC-DAD).