Eva Srečnik (Author), Robert Roškar (Mentor)

Abstract

Lipofilni vitamini so organske spojine potrebne za normalno delovanje številnih funkcij v človeškem telesu, kot so vid (vitamin A), homeostaza kalcija in fosfatov (vitamin D), antioksidativna zaščita v celičnih membranah (vitamin E) in strjevanje krvi (vitamin K). V telo jih vnašamo s hrano, občasno pa tudi z vitaminskimi pripravki. Po javnomnenjski raziskavi Ministrstva za zdravje o rabi prehranskih dopolnil so vitaminski pripravki po pogostosti jemanja na drugem mestu, zato je kontrola njihove kakovosti še posebej pomembna, predvsem tistih z vitaminoma A in D, ki ob prekomernem vnosu lahko delujeta toksično. Zato je bil glavni cilj magistrske naloge preveriti vsebnost in stabilnost lipofilnih vitaminov v izbranih zdravilih in prehranskih dopolnilih pri dveh različnih temperaturah shranjevanja (25°C in 40°C). V ta namen smo razvili hitro in enostavno analizno metodo, ki nam omogoča sočasno vrednotenje 5 lipofilnih vitaminov (v oblikah, ki se najpogosteje pojavljajo v vitaminskih pripravkih – A-palmitat, D3, K1, E-acetat in provitamin A – β-karoten) in koencima Q10 v raztopinah, emulzijah, mehkih kapsulah in tabletah. Metoda vključuje pripravo vzorca z ekstrakcijo z dodanim butilhidroksitoluenom v zmes tetrahidrofurana, acetonitrila in vode v razmerju 45:50:5 (v/v/v) za tekoče farmacevtske oblike ter ekstrakcijo z n-heksanom in naknadnim sušenjem vzorca s prepihovanjem z dušikom pri povišani temperaturi za mehke kapsule in tablete. Vzorce smo analizirali s tekočinsko kromatografijo visoke ločljivosti sklopljeno z UV detektorjem, ki smo jo validirali v skladu z ICH smernicami in potrdili njeno selektivnost, linearnost (R2 > 0,999), točnost (96 – 102%), natančnost (RSD < 2%), robustnost ter dokazali dobro učinkovitost ekstrakcije (93–108%) za vse analite. Primernost analizne metode smo preverili z analizo 12 pripravkov, ki so vsebovali enega ali več lipofilnih vitaminov in koencim Q10. Vsebnost lipofilnih vitaminov je bila pri večini pripravkov višja od deklarirane. Največje odstopanje od deklariranih vsebnosti smo opazili pri dveh prehranskih dopolnilih, za katera veljajo manj strogi predpisi. Trimesečna stabilnostna študija pripravkov po odprtju ovojnine je pokazala, da so lipofilni vitamini pri višji temperaturi shranjevanja bolj nestabilni. Pri 40°C smo ugotovili največji upad vsebnosti pri tekočih pripravkih, manjšega pri tabletah, pri mehkih kapsulah pa je bil upad vsebnosti minimalen. Pri 25°C smo znaten upad vsebnosti ugotovili le pri tekočih pripravkih, kjer se je A-palmitat izkazal za najmanj stabilnega.

Keywords

lipofilni vitamini;koencim Q10;vitaminski pripravki;HPLC;tekočinska kromatografija visoke ločljivosti;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FFA - Faculty of Pharmacy
Publisher: [E. Srečnik]
UDC: 543.544.5:613.292(043.3)
COBISS: 4332401 Link will open in a new window
Views: 347
Downloads: 105
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Other data

Secondary language: English
Secondary title: Evaluation of the content and stability of lipophilic vitamins and coenzyme Q10 in medicines and nutrition supplement by high performance liquid chromatography
Secondary abstract: Lipophilic vitamins are organic compounds which are essential for a variety of physiological functions in the human body, such as vision (vitamin A), calcium and phosphate homeostasis (vitamin D), antioxidative protection in cell membranes (vitamin E) and blood coagulation (vitamin K). As lipophilic vitamins, with the exception of vitamin D3, can not be obtained by endogenous synthesis, food or vitamin supplements are their main source. A public opinion poll of the Ministry of Health showed that vitamin preparations are the second most frequently used nutritional supplements, so quality control of these preparations is extremely important, especially because of the risk of toxicity from excessive intake of vitamins A and D. Therefore, the main objective of the thesis was to evaluate the content and the stability of lipophilic vitamins in selected medicines and nutrition supplements at two different storage temperatures (25°C and 40°C). For this purpose, a rapid and simple analytical method for simultaneous quantification of five lipophilic vitamins (in most commonly used forms – A-palmitate, D3, K1, E-acetate and provitamin A – β-carotene) and coenzyme Q10 in liquid and solid preparations was developed. The method involves simple and fast extraction procedures: dilution with the mixture of tetrahydrofuran, acetonitrile and water (50/45/5, v/v/v) containing butylated hydroxytoluene for liquid preparations and extraction with n-hexane and evaporation of organic extracts under nitrogen at 40°C for solid preparations. The samples were analyzed by high performance liquid chromatography coupled with UV detector. The method was successfully validated according to the ICH guidelines in terms of selectivity, linearity (R2 > 0,999), adequate accuracy (96 – 102%), precision (RSD < 2%), robustness and extraction efficiency (93–108%) for all anaytes. The adequacy of the method was confirmed by testing 12 vitamin preparations containing one or more lipophilic vitamins and coenzyme Q10. The content of vitamins in the majority of tested preparations was higher than declared on the label. The biggest deviation from declared content was observed in two nutritional supplements. The three-month stability study after opening has revealed that lipophilic vitamins are more unstable at 40°C. At both storage temperatures, liquid preparations were more unstable compared to solid preparations. At 25°C, only in liquid preparations significant decline in the content was observed, where A-palmitate was found to be at least stable.
Secondary keywords: Prehranski dodatki;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. Ljubljana, Fak. za farmacijo
Pages: V, 65 f., I-IV f. pril.
ID: 12044632