Uniform Master's Study Programme Pharmacy
Tjaša Steiner (Author), Robert Roškar (Mentor)

Abstract

Eksogeni vnos koencima Q10 (Q10), ki je nujen za delovanje celic in je edini endogeni lipofilni antioksidant, je pomemben zaradi zmanjševanja hitrosti njegove biosinteze s starostjo. Rezultati novejših študij kažejo, da je zaradi večje absorpcije boljša izbira reducirana oblika (rQ10), ki sicer velja za manj stabilno obliko Q10. Čeprav si obliki nista enakovredni, v trenutnih predpisih preverjanja kakovosti najdemo samo kriterije o vsebnosti skupnega Q10 v izdelkih. Preskusili smo 3 že razvite metode za merjenje vsebnosti Q10: metodo za sočasno merjenje vsebnosti rQ10 in oksidirane oblike Q10 (oQ10) ter metodi za merjenje skupnega Q10, ki vključujeta oksidacijo oz. redukcijo Q10 v vzorcu. Izbrali smo 10 izdelkov v obliki mehkih in trdih kapsul (zdravilo in prehranska dopolnila) z navedeno oQ10 oz. rQ10. Nekateri so vsebovali tudi askorbinsko kislino (AK). Metodi priprave vzorcev z oksidacijo oz. redukcijo vzorca smo dodatno optimizirali. Vpeljane spremembe niso vplivale na ustreznost kromatografske analizne metode, saj smo dokazali ustrezno selektivnost, linearnost, točnost in natančnost pri merjenju vsebnosti Q10. S tremi uporabljenimi metodami smo dobili primerljive rezultate vsebnosti skupnega Q10, kar smo tudi potrdili s statističnim testom. Kvantitativno smo vrednotili vsebnost in stabilnost posameznih oblik in skupnega Q10 v izdelkih. Ugotovitve smo dodatno preverili z izvedbo pospešene stabilnostne študije pri temperaturi 40 °C in relativni vlažnosti 75 %, ki je trajala 3 mesece. Izdelka z navedeno rQ10 sta ustrezala zahtevam Ameriške farmakopeje (90,0 – 115,0 % navedene vsebnosti) v vsebnosti navedene oblike in skupnega Q10 tudi po koncu pospešene stabilnostne študije. Pri izdelkih z navedeno oQ10 je bila vsebnost oQ10 pred izvedbo študije znotraj mej pri 2 izdelkih od 8, če smo upoštevali skupni Q10 pa pri 4 izdelkih. V večini izdelkov v obliki mehkih kapsul je bilo neskladje vsebnosti oQ10 večje pri izdelkih z AK, kar so potrdili tudi rezultati merjenja vsebnosti Q10 v različnih serijah zdravila z različno dolgim časom od izdelave, ki so bili shranjeni pri sobnih pogojih. V izdelkih v obliki trdih kapsul AK ni vplivala na pretvorbo oQ10. Vsebnost skupnega Q10 ni bila ustrezna pri 4 izdelkih od 10, od tega je en izdelek imel vsebnost preseženo, pri treh pa je bila nižja od 90 %. Ker se je vsebnost skupnega Q10 izrazito manj znižala kot razmerje med posameznima oblikama Q10, sklepamo, da se obliki med shranjevanjem pretvarjata ena v drugo. S stališča kakovosti je prisotnost obeh oblik Q10 neprimerna, če to ni navedeno, vendar so takšni izdelki zaradi večje biološke uporabnosti rQ10 boljši, kot če bi vsebovali samo oQ10.

Keywords

koencim Q10;askorbinska kislina;tekočinska kromatografija visoke ločljivosti;vsebnost skupnega Q10;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FFA - Faculty of Pharmacy
Publisher: [T. Steiner]
UDC: 543.544.5 :577.161.6(043.3)
COBISS: 4640625 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Evaluation of the content and stability of coenzyme Q10 in medicines and nutrition supplements by high performance liquid chromatography methods
Secondary abstract: Coenzyme Q10 (Q10) as the only endogenous lipophilic antioxidant is essential for proper cell functions in our body. Q10 supplementation is important because the rate of its biosynthesis decreases with age. New studies have shown that the reduced Q10 (rQ10) is preferred due to its higher bioavailability, but is also the less stable form of Q10. In the current quality control regulations there are only criteria for content determination of the total Q10 in final products, even though both forms of Q10 are not equivalent. Three previously developed methods for Q10 determination in products were tested: a method for simultaneous determination of rQ10 and oxidised Q10 (oQ10), and two methods including either complete oxidation or reduction of the Q10 in the sample for determination of the total Q10. Ten products in form of soft or hard capsules were tested (medicine and dietary supplements) with labelled oQ10 or rQ10. Ascorbic acid (AA) was also present in some products. Both methods with Q10 conversions were additionally optimised and the adequacy of the instrumental method was proved in terms of selectivity, linearity, accuracy, and precision. All three used methods provided comparable results of the total Q10 content in the tested products, which was also confirmed by a statistical test. The main objective of our thesis was to evaluate the content and stability of both Q10 forms and the total Q10 in selected products. The findings were supported by a 3-month accelerated stability study (40 °C and 75 % relative humidity). Both products with labelled rQ10 met the United States Pharmacopoeia acceptance criteria (90.0 – 115.0 % labelled amount of Q10 content) for the rQ10 and the total Q10 content even until the end of the stability study. In the oQ10 labelled group 2 out of 8 products met requirements for the oQ10 and 4 products for the total Q10 content at the beginning of the study. Deviations from the labelled oQ10 content were greater in soft capsules with AA. The same was also proved for the medicine stored at room temperature by comparison the Q10 content of batches with various shelf lives. In hard capsules the conversion of oQ10 was not affected by AA. In 6 out of 10 products the total Q10 content met the specification limit; one product substantially exceeded and three products were slightly under 90 %. Stability study showed that the total Q10 is considerable more stable than both Q10 forms, which leads to a conclusion that the main instability is the conversion between both forms. A product is not suitable in terms of its quality if a Q10 form is present but not labelled. This especially counts for the rQ10 which is the preferred form of Q10 due to its higher bioavailability.
Secondary keywords: Ubikinon;Tekočinska kromatografija;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. Ljubljana, Fak. za farmacijo
Pages: V, 67 f.
ID: 12042770