Determination of Vitamin C Content in Commercial Pharmaceutical Preparations

Abstract

Vitamins are a group of organic compounds with different chemical structures and properties. Together with mineral substances, they form regulatory substances. They are necessary, in extremely small quantities, for humans and animals for proper growth, development, reproduction and various metabolic processes and functions. The human body has lost the ability to synthesize vitamins during evolution, so they must be ingested through food. Thus, they belong to the essential nutrients. The exception is vitamin D, which is produced within the human body, under the action of ultraviolet radiation by photochemical conversion of 7-dihydrocholesterol precursors. Likewise, vitamin K and biotin can be synthesized by bacteria in the intestinal flora. The term vitamin was introduced by the Polish biochemist Casimir Funk in the early 20th century. In 1912, he isolated a new amine from rice bran, today known as thiamine or vitamin B1. The name comes from the word vita, which translated from Latin means life, and the chemical name amin. There are 13 different types of vitamins and each has its own role. They are active not only in the development of the nervous system, vision, numerous reactions in the human body, but also bone mineralization. Today's method of food production and processing, along with industrial food pollution and the stressful lifestyle we conduct, leads to an increased need for vitamins. Most vitamins have antioxidant capacity. If they are present in sufficient quantities, the immune system is able to fight against the harmful effects of free radicals. The importance of vitamins is reflected in the fact that they are precursors of many coenzymes, and the vitamin part in the structure of coenzymes is most often the carrier of coenzyme function. The classification of vitamins is based on their solubility in water or fat. They are divided into hydrosoluble and liposoluble. The former consists of B vitamins and vitamin C, while the latter includes vitamins A, D, E, and K. Liposoluble vitamins can be stored in large quantities inside the body and the resulting hypervitaminosis can pose a health risk. Hydrosoluble substances are easily and quickly excreted from the body, so it is necessary to take them continuously in order to avoid their deficiency. On the one hand, insufficient entry of one or more vitamins causes a deficiency of vitamins in the body, which is reflected in the appearance of various diseases called hypovitaminosis (insufficient vitamin entry) or avitaminosis (complete absence of vitamins). Deficiency develops gradually, most often due to increased needs of the body (pregnant women, nursing mothers, children and vegetarians, etc.), but also due to general malnutrition, poor absorption, inadequate diet, parenteral nutrition, use of drugs, chronic alcoholism and hereditary metabolism disorders. Precautionary use of vitamins through diet prevents numerous disorders such as rickets, night blindness, skin diseases, and others. On the other hand, excessive vitamin intake is referred to as hypervitaminosis and most often occurs due to irrational use of synthetic vitamin products. Hypervitaminosis is characteristic for vitamins A and D. The aim of this thesis work is the validation of the analytical method and the determination of the content of vitamin C in pharmaceutical preparations available in free sale in the territory of the Republic of Serbia.