Physicochemical quality profiles of commercial oral tablets and capsules containing lutein – impact of insufficient specific sanitary regulations

Abstract

Dietary supplements in many countries such as the USA do not require registration prior to commercialization. The Agência Nacional de Vigilância Sanitária (ANVISA) registers substances with functional properties as foods. Lutein is a carotenoid with antioxidant activity available on the market. However, no regulatory mandates exist to govern the design of quality control tests, which are necessary to ensure formulation effectiveness. Therefore, in the present study, tablet and dosage formulations from different manufacturers were tested following general methods outlined in the Brazilian and American Pharmacopeias. The averageweight, disintegration, content and dose uniformity assays were performed for all tablets and capsules, whereas hardness assays were only performed on tablets. None of the 10 formulations studied were found to be of satisfactory quality. Of all tablets tested, two had no-significant available lutein content, which may indicate adulteration. The capsules displayed adequate amounts of lutein, however had alarmingly negative disintegration and dissolution test results, which may contribute to non-bioavailability of lutein. All formulations analyzed are currently being marketed in the Brazilian and American markets. The low physicochemical performance in these formulations can be explained by the lack of specific regulations, which are necessary to ensure the quality of lutein-containing products on the market.

Evaluation of Physicochemical Properties of Beetroot-Based Dietary Supplements

“…It is well-known that the uniformity of the weight of the individual dosage units guarantees the uniformity of the dosage of the product. This parameter is particularly important to provide the same dose of active substances during each administration, therefore, to ensure the repeatable pro-health effect [38]. The proven uniformity of weight of the investigated dietary supplements indicates their repeatable production.…”

“…An adequate tablet strength should provide fracture toughness to permit dosing and, at the same time, adequate disintegration upon digestion. Unfortunately, inappropriate manufacturing of dosage form (e.g., high compression force, unsuitable excipients) may inhibit both the disintegration of dosage form and dissolution of active substances [38]. In such a case, the digestive processes, after in vivo administration of the product, may not be sufficient to provide the liberation of the components for absorption.…”

“…Gusev et al [41] found that some supplements' ingredients (such as epigallocatechin gallate) may require more biologically relevant destructive forces to disintegrate and the USP protocols should consider different botanicals. Other research data also indicate poor quality and formulation issues with dietary supplements assessed by the USP requirements [38,42].…”

Suplementy diety – specyficzna żywność

“…Niezależnie przeprowadzone eksperymenty według wytycznych Farmakopei Amerykańskiej dowodzą jednak, że niektóre z przebadanych suplementów diety z witaminą A [61], luteiną [62] oraz żelazem [63] charakteryzowały się niskim uwalnianiem substancji czynnej z postaci produktu. Badane produkty w kapsułkach z luteiną uwolniły zaledwie 20% substancji w ciągu 180 min badania, podczas gdy z tabletek uwolniło się nie mniej niż 80% w tym samym czasie [62]. Wyniki testów czasu rozpadu i szybkości rozpuszczania suplementów diety z luteiną nie były satysfakcjonujące.…”

“…Według wytycznych Farmakopei Stanów Zjednoczonych (USP) całkowity rozpad tabletek konwencjonalnych powinien trwać do 30 min, a w ciągu godziny powinno uwolnić się nie mniej niż 75% deklarowanej ilości substancji czynnej [64]. Ponadto w dwóch produktach nie stwierdzono obecności deklarowanego stężenia luteiny [62]. Podobne wyniki stwierdzono dla suplementów z witaminą A, które uwalniały ponad 80% substancji aktywnej w ciągu 45 min, jednak dwa produkty nie spełniły tego warunku, a w przypadku jednego w ogóle nie stwierdzono obecności witaminy A [61].…”