^#.^t28: TLC of Antithrombotics
Heparin is a glycosaminoglycan-mostly negatively charged biomolecule due to sulfate groups (Williams 2010). Proteins and peptides are charged depending on the amino acids side chains. Thus, these compounds are usually separated based on the inuence of the electric eld-electrophoresis. However, when glycosaminoglycans are enzymatically digested, oligosaccharides are formed that can be analyzed by thin-layer chromatography (TLC) (Chai, Rosankiewicz, and Lawson 1995; Qiu, Tanikawa, Akiyama, Toida, Koshiishi, and Imanari 1993). Fibrinolytics are enzymes, thus they are characterized as protein structures that are usually analyzed by techniques other than TLC. One of the most commonly used antithrombotics is acetylsalicylic acid in daily dose of 100 mg. As a nonsteroidal anti-inammatory drug (NSAID), it is used in dosage forms of 300 or 500 mg (Cox 2008), thus TLC of acetylsalicylic acid is described in Chapter 18.