ABSTRACT
Substances used as excipients must not be toxic and must have no pharmacological action in the amount used. In this respect, natural products have an advantage. Monomers, plas-ticizers, softeners, and fillers contained in the synthetic polymers may be toxic, while pure polymers are characterized by low toxicity. Nevertheless, at the stage of polymer chemistry development, it is easier to obtain polymers with specific desirable properties, especially solubility, which plays an important role in extended-release dosage forms formulation. Pectins have similar applications. Pectin consists chiefly of linear polymers of partially methoxylated polygalacturonic acids. In the formulation of extended-release tablets with antihistamine and potassium chloride, a hydrophilic matrix of carboxymethylcellulose sodium was applied. Carboxyme-thylcellulose sodium forms insoluble salts in the presence of some electrolytes, e.g., aluminium sulfate. This was applied in the formation of films on chloramphenicol particles using the following method.
