Analysis of Vitamin A in Multivitamin Products

Vitamin A is present in multivitamin products mainly in the form of retinol esters: retinyl acetate, retinyl palmitate, and beta carotene—retinol precursor (dimer) found in plants, which is capable of converting into retinol in liver cells. Retinol is determined in medicinal products primarily by high performance liquid chromatography (HPLC), with preliminary purification and vitamin isolation by liquid-liquid extraction. However, scientific literature also describes other methods of sample preparation and analysis of such compounds. An important issue is differentiation of vitamin A from other fat-soluble vitamins often included as components in multivitamin products. The aim of the study was to analyse and summarise data on current methods used for determination of vitamin A and its derivatives in medicinal products. The authors analysed the range of vitamin A products authorised in the Russian Federation, and the test methods described in their product specification files. The study demonstrated that the test method most often used for determination of retinol esters was HPLC with isocratic elution mode using octadecylsilyl packing in the reverse-phase mode, and, less frequently, aminopropylsilyl packing in the normal phase mode. Determination of beta carotene in medicinal products is most often performed using spectrophotometry.

Effect of Different Packaging Materials on Some Vitamins and Minerals of the Pasteurized Camel Milk

In this study the level of Pasteurized camel milk vitamins and minerals, vitamin A (Retinyl Acetate), Vitamin C (Ascorbic Acid), Selenium were monitored, Phosphorus and Calcium for 30 days period started day 0, through day 7, day 14, day 21 and day 30, different types of packaging materials (I) (PET) Bottle, (ii) (PP) Cup,(iii) (PS) Cup,(iv) (LDPE) Bottle,(v) (LPET) Bottle,(vi (HDPE) Bottle,(vii) Aluminum Cans, (viii) Glass(Emerald Green) and (ix) Cartoon bottles (250 ml size) were dispensed with the Pasteurized camel milk (80 ˚C, 16 s) at Aseptic condition and storage temperature 5 ˚C, to find out best packaging materials to transport high value from this nutrient to the end consumers, Result shown there is significant differences within packaging materials responds of test results about (Vitamin A), So The best packaging materials on Vitamin A of pasteurized Camel Milk is: Carton, Aluminum Can, Glass bottle) Respectively, Vitamin C shown significant differences within packaging materials responds of test results, So the best packaging materials on Vitamin C is:(Aluminum Can, Carton, Glass bottle) Respectively. Minerals results shown that there were no significant differences within packaging materials responds of test results about (Selenium (Se)) because the sig = (0.997) more than 0.05 and 0.01. so we can say responds in group equally at all packaging materials, Calcium results shown that there were significant differences within packaging materials, So the best packaging materials for Calcium (Ca) is:(HDPE, PET, LDPE) Respectively. Phosphorus also shown significant differences within packaging materials because the sig = (0.000) Less than 0.05 and 0.01. so responds in group not equally at all packaging materials, the best packaging materials on Phosphorous (P) s:(LDPE, HDPE, PET) respectively.

Transfer Investigations of Lipophilic Drugs from Lipid Nanoemulsions to Lipophilic Acceptors: Contributing Effects of Cholesteryl Esters and Albumin as Acceptor Structures

When studying the release of poorly water-soluble drugs from colloidal drug delivery systems designed for intravenous administration, the release media should preferentially contain lipophilic components that represent the physiological acceptors present in vivo. In this study, the effect of different acceptor structures was investigated by comparing the transfer of fenofibrate, retinyl acetate, and orlistat from trimyristin nanoemulsion droplets into lipid-containing hydrogel particles, as well as to bovine serum albumin (BSA). A nanodispersion based on trimyristin and cholesteryl nonanoate was incorporated into the hydrogel particles (mean diameter ~40 µm) in order to mimic the composition of lipoproteins. The course of transfer observed utilizing the lipid-containing hydrogel particles as an acceptor was in relation to the lipophilicity of the drugs: the higher the logP value, the slower the transfer. There was no detectable amount of the drugs transferred to BSA in liquid solution, demonstrating clearly that albumin alone does not contribute substantially as acceptor for the lipophilic drugs under investigation in this study. In contrast, cholesteryl nonanoate contributes to a much greater extent. However, in all cases, the partition equilibrium of the drugs under investigation was in favor of the trimyristin emulsion droplets.

Asiatic Acid, a Natural Compound that Exerts Beneficial Effects on the Cystometric and Biochemical Parameters in the Retinyl Acetate-Induced Model of Detrusor Overactivity

Scientists have been constantly looking for new synthetic and natural compounds that could have beneficial effects in bladder overactivity. Our attention was drawn by asiatic acid that influences a number of molecules and signaling pathways relevant for the proper functioning of the urinary tracts in humans. In the present project we wanted to check whether asiatic acid would have positive effects in the confirmed animal model of detrusor overactivity (DO) and whether it would affect the bladder blood flow, urothelium thickness, inflammatory and oxidative stress markers, neurotrophic and growth factors, and other parameters important for the activity of the urinary bladder. The outcomes of our study showed that a 14-day administration of asiatic acid (30 mg/kg/day) by oral gavage normalizes the cystometric parameters corresponding to DO and reduces the accompanying oxidative stress (measured by the levels of malondialdehyde–61,344 ± 24,908 pg/ml vs. 33,668 ± 5,071 pg/ml, 3-nitrotyrosine–64,615 ± 25,433 pg/ml vs. 6,563 ± 1,736 pg/ml, and NOS2–2,506 ± 411.7 vs. 3,824 ± 470.1 pg/ml). Moreover, it decreases the urinary secretion of neurotrophins (BDNF–304.4 ± 33.21 pg/ml vs. 119.3 ± 11.49 pg/ml and NGF–205.5 ± 18.50 vs. 109.7 ± 15.94 pg/ml) and prevents the changes in a range of biomarkers indicating the dysfunction of the urinary bladder, CGRP (421.1 ± 56.64 vs. 108.1 ± 11.73 pg/ml), E-Cadherin (773.5 ± 177.5 pg/ml vs. 1,560 ± 154.5 pg/ml), OCT3 (3,943 ± 814.6 vs. 1,018 ± 97.07 pg/ml), SNAP-23 (6,763 ± 808.9 pg/ml vs. 3,455 ± 554.5 pg/ml), SNAP-25 (2,038 ± 162.7 pg/ml vs. 833.3 ± 65.48), substance P (171.7 ± 16.86 pg/ml vs. 65.07 ± 8.250 pg/ml), SV2A (1,927 ± 175.3 pg/ml vs. 1,154 ± 254.9 pg/ml), tight junction protein 1 (360.1 ± 95.05 pg/ml vs. 563.4 ± 65.43 pg/ml), VAChT (16,470 ± 2,419 pg/ml vs. 7,072 ± 1,339 pg/ml), VEGFA (318.3 ± 37.89 pg/ml vs. 201.5 ± 22.91 pg/ml). The mentioned parameters are associated with smooth muscle contractions, urothelial barrier, transportation and release of transmitters, or bladder compensation. Thus, the presented findings allow to suggest a possible future role of asiatic acid in the prevention of conditions accompanied by DO, such as overactive bladder.

Transfer of Lipophilic Drugs from Nanoemulsions into Lipid-Containing Alginate Microspheres

Knowledge about the release behavior and drug retention properties of colloidal carriers is of essential importance for quality control as well as to predict in vivo performance. When conducting release studies from such systems, the release media should preferentially contain lipophilic acceptor components in order to mimic physiological conditions. In this study, transfer from a trimyristin nanoemulsion into lipid-containing hydrogel beads was investigated for fenofibrate, cannabidiol, retinyl acetate, orlistat, and lumefantrine. To generate the acceptor system, a trimyristin nanoemulsion was incorporated into Ca-alginate microspheres (mean diameter ~40 µm) with a spraying method. Using this approach, the advantages of small lipophilic acceptor particles with a large interfacial area were combined with a single separation process from the donor via a filtration step. The method was applicable to distinguish between fast (fenofibrate) and slow drug transfer (lumefantrine) with good time resolution. Lipophilicity, estimated according to the calculated logP value of the respective drug, was a major factor influencing the transfer performance: the higher the logP value, the slower the transfer. This experimental setup is a promising technique to investigate the release of poorly water-soluble drugs from various types of nanocarriers under closer to physiological conditions than with many other methods currently applied.

Breast Milk–Derived Retinol Is a Potential Surrogate for Serum in the 13C-Retinol Isotope Dilution Test in Zambian Lactating Women with Vitamin A Deficient and Adequate Status

ABSTRACT Background Vitamin A (VA) deficiency (VAD) affects ∼19 million pregnant women worldwide. The extent of VAD in Zambian women of reproductive age is unknown owing to lack of survey inclusion or the use of static serum retinol concentrations, a low-sensitivity biomarker. Objectives This cross-sectional study employed isotopic techniques to determine VA status with serum and milk among women aged 18–49 y (n = 197) either lactating with infants aged 0–24 mo or nonlactating with or without infants. Methods Assistants were trained and piloted data collection. Demographic data, anthropometry, and relevant histories were obtained including malaria and anemia. For retinol isotope dilution (RID), baseline fasting blood and casual breast milk samples were collected before administration of 2.0 μmol 13C2-retinyl acetate and 24-h dietary recalls. On day 14, blood (n = 144) and milk (n = 66) were collected. Prevalence of total liver VA reserves (TLR) ≤0.10 μmol/g was defined as VAD with comparison to the DRI assumption of 0.07 μmol/g as minimally acceptable for North Americans. Results When a 20% adjustment for dose lost to milk was made in the RID equation for lactation, mean total body VA stores (TBS) for lactating women were 25% lower than for nonlactating women (P < 0.01), which was not the case without adjustment (P = 0.3). Mean ± SD TLR for all women were 0.15 ± 0.11 μmol/g liver. Using retinol purified from breast milk instead of serum for RID analysis yielded similar TBS and TLR, which were highly correlated between methods (P < 0.0001). Serum retinol ≤0.70 μmol/L had 0% sensitivity using either VAD liver cutoff and milk retinol ≤1.0 μmol/L had 42% sensitivity for VAD at 0.10 μmol/g. Conclusions Determining accurate VA status among women of reproductive age, especially lactating women, forms a basis for extrapolation to the general population and informing policy development and program implementation.

A Compartmental Model Describing the Kinetics of β-Carotene and β-Carotene-Derived Retinol in Healthy Older Adults

ABSTRACT Background Descriptive and quantitative information on β-carotene whole-body kinetics in humans is limited. Objectives Our objective was to advance the development of a physiologically based, working hypothesis compartmental model describing the metabolism of β-carotene and β-carotene-derived retinol. Methods We used model-based compartmental analysis (Simulation, Analysis and Modeling software) to analyze previously published data on plasma kinetics of [2H8]β-carotene, [2H4]β-carotene-derived retinol, and [2H8]retinyl acetate-derived retinol in healthy, older US adults (3 female, 2 male; 50–68 y); subjects were studied for 56 d after consuming doses of 11 μmol [2H8]β-carotene and, 3 d later, 9 μmol [2H8]retinyl acetate in oil. Results We developed a complex model for labeled β-carotene and β-carotene-derived retinol, as well as preformed vitamin A, using simulations to augment observed data during model calibration. The model predicts that mean (range) β-carotene absorption (bioavailability) was 9.5% (5.2–14%) and bioefficacy was 7.3% (3.6–14%). Of the absorbed β-carotene, 41% (25–58%) was packaged intact in chylomicrons and the balance was converted to retinol, with 58% (42–75%) transported as retinyl esters in chylomicrons and 0–2% by retinol-binding protein. Most (95%) chylomicron β-carotene was cleared by the liver. Later data revealed differences in the metabolism of retinyl acetate- versus β-carotene-derived retinol; data required that both β-carotene and derived retinol be recycled from extrahepatic tissues (e.g. adipose) in HDL. Of total bioconversion [73% (47–99%)], 82% occurred in the intestine, 17% in the liver, and 0.83% in other tissues. Conclusions Our model advances knowledge about whole-body β-carotene metabolism in healthy adults, including the kinetics of transport in all lipoprotein species, and suggests hypotheses to be tested in future studies, such as the possibility that retinol derived from hepatic conversion over a long period of time might contribute to plasma retinol homeostasis and total body vitamin A stores.