Multivitamin Preparations Research Articles

Urticaria Associated With Parenteral Nutrition

We report a 53-year-old female patient with short bowel syndrome who developed urticaria after administration of cyclic parenteral nutrition (PN). The urticaria occurred 2 hours into the 12-hour nocturnal infusion and resolved completely 1 hour after discontinuation of the PN infusion. The urticaria occurred despite removing lipids from the 3-in-1 PN solution. The urticaria did not occur when the multivitamin preparation was removed from the PN. Upon rechallenge with a PN solution containing a multivitamin, the urticaria reoccurred. Prick skin testing using the multivitamin in increasing aliquots was negative. Serum tryptase and 12-hour urinary histamine level during PN infusion containing the multivitamin was unchanged compared with baseline measurements. The patient had no allergic reaction using a similar dose of an oral multivitamin. This case illustrates that allergic reactions from PN infusion may occur and that the multivitamin preparation can be the cause.

Determination of Fe(II) and Zn(II) in vitrum prenatal by ion chromatography (IC). Comparison with classical and derivative spectrophotometry (D0, D1, and D2) with metrian, metriap, metriarez-γ, and metidarez-β dyes and with atomic absorption spectrometry

3-Mercapto-5-(2′-hydroxynaphthylazo-1′)-1,2,4-triazole (metrian); 3-mercapto-5-(3′,4′-dihydroxyphenylazo-1′)-1,2,4-triazole (metriap); 3-mercapto-5-(2′,4′-dihydroxy-3′-carboxyphenylazo-1′)-1,2,4-triazole (metriarez-γ), and 2-mercapto-5-(2′,4′-dihydroxy-5′-carboxyphenylazo-1′)-1,3,4-thiadiazole (metidarez-β) have been used to determine, by different methods, milligram quantities of Fe(II) and Zn(II), present together in pharmaceutical preparations, both multivitamin preparations and preparations containing microelements. Results from ion chromatography (IC) were compared with those from classical spectrophotometry (D 0 ), derivative spectrophotometry (D 1 and D 2 ), and atomic absorption spectrometric (AAS). Results were analyzed statistically and compared with the declared amount. The advantages of the proposed method for determination of Fe(II) and Zn(II) include its excellent precision and the reproducibility of the results.

Dietary supplement use in adolescents

As prevalence rates of dietary supplement use are observed to be increasing in adolescents and the population in general, questions need to be asked about the efficacy, motivations, and consequences of such usage. Focusing mainly on individuals between the ages of 12 to 19 (adolescents) this review will highlight current prevalence rates, types of supplements being consumed, reasons for consumption, and concerns regarding physiological, psychological, knowledge transfer, and regulatory aspects of supplement use. Studies have indicated the prevalence of dietary supplement usage by adolescents range from approximately 10% to as high as 74%. Some of the highest rates of usage appear in chronically ill adolescents. Multivitamin and mineral preparations are the most common supplements being consumed; however, many studies indicate that adolescents are using other substances like creatine, herbals, or protein supplements. Some of the most appealing supplements among this age group are those that enhance athletic performance or physical appearance. Recent literature suggests three key moderating factors for supplement use in adolescents: health status, gender, and level of physical activity involvement. As the dietary supplement industry is now a multi-billion dollar industry, there is growing pressure, and a subsequent need for research to establish the efficacy and safety of these products particularly for adolescent users. The psychological and educational components of such use cannot be ignored as they play an equally important role in the health and safety of adolescents.

Giardiosis in camels (Camelus dromedarius)

Giardiosis in camels (<i>Camelus dromedarius</i>)

Determination of macro and trace element in multivitamins preparations by inductively coupled plasma optical emission spectrometry with slurry sample introduction

A slurry sampling technique has been utilised for elemental analysis of multivitamins preparations using inductively coupled plasma-emission spectrometry (ICP-OES). For results comparison, samples were mineralised. Slurry concentration 0.1–0.2% m/v in 6% v/v HNO 3, was used. The calibration by water standard solutions, slurry standards and standard additions were tested for determination above-mentioned elements in slurries. The method offers good precision for macro elements (RSD ranged from 5% to 10%). For in-home control sample, the measured concentrations are in satisfactory agreement with independent laboratories. For the analysed multivitamin preparations, the found element concentration is compared to amount declared by producer. The concentrations of Ca, Mg, P, K, Fe, Mn, Zn, Cu and Cr, Ni, V were determined in the range 1000–100,000 and 5–50 μg g −1, respectively. The slurry ICP-OES analysis was found to be suitable for quality control monitoring of multivitamin preparations and could be useful as a routine procedure.

Association between Hydrogen Peroxide-Dependent Byproducts of Ascorbic Acid and Increased Hepatic Acetyl-CoA Carboxylase Activity

Parenteral multivitamin preparation (MVP) induces fatty liver in neonatal guinea pig pups; this is prevented by photoprotection. Photo-excited riboflavin present in MVP generates H(2)O(2) and molecules with masses of 136 and 208. We hypothesized that H(2)O(2) initiates the peroxidation of ascorbic acid (AA), producing biologically active byproducts affecting hepatic lipid metabolism. Mass spectrometry (MS) documented the participation of H(2)O(2) and photo-excited riboflavin (Ribo) in the formation of AA byproducts. Sixteen 3-day-old guinea pig pups received an intravenous solution (50 g/L dextrose + 4.5 g/L NaCl + 1 kIU/L heparin) at 240 mL x kg(-1) x day(-1), enriched with control or test mixtures, for 4 days. The control mixture was photo-protected AA + Ribo (without byproducts or H(2)O(2)), and the test mixture was AA + Ribo treated to generate AA byproducts without H(2)O(2). Hepatic acetyl-CoA carboxylase (ACC) activity was determined after 4 days. Fourth-day urine samples were analyzed by MS. Data were treated by ANOVA (alpha = 0.05). H(2)O(2) did not influence the classic degradation of AA, as the generation of 2,3-diketogulonic acid was not affected. In contrast, the formation of molecules with masses of 136 and 208 was H(2)O(2) and time dependent. ACC activity was higher (P <0.01) in animals receiving high concentration of these molecules; its hepatic activation correlated (P <0.01) with the urinary concentration of molecule-208. H(2)O(2) at concentrations found in the clinical setting of total parenteral nutrition induce the transformation of dehydroascorbic acid into compounds that have the potential to affect lipid metabolism. These molecules have peroxide and aldehyde functions.

Reduced Bile Flow Associated With Parenteral Nutrition Is Independent of Oxidant Load and Parenteral Multivitamins

Reduction in bile flow is a characteristic of cholestasis related to parenteral nutrition. Light exposure of parenteral multivitamin preparations is the major source of peroxides contaminating parenteral nutrition solutions. They may contribute to local oxidative stress. Oxidants are reported to affect transport mechanisms across the hepatocyte membrane into bile. The authors hypothesize that an oxidant-antioxidant imbalance is involved in parenteral nutrition related cholestasis. The aim of this study was to investigate the roles of multivitamin preparations and peroxides on bile flow in newborn guinea pigs receiving parenteral nutrition. Three-day-old guinea pigs were fed enterally or parenterally with solutions containing 8% dextrose/0.45% NaCl +/- multivitamin preparation +/- amino acids +/- lipids. The influence of the oxidant-antioxidant balance on bile flow was evaluated using 500 microM hydrogen peroxide and 1% and 3% multivitamin preparations +/- Na metabisulfite. Four days later, animals were anesthetized and bile flow was recorded over 2 hours. Glutathione determinations were performed on bile and liver samples. The percentage of oxidized glutathione, reflecting the redox status, was used as a marker of oxidative stress. Data were compared by analysis of variance with P < 0.05. Bile flow decreased first on initiating dextrose + NaCl infusion (a 25% decrease) and subsequently by adding amino acids (a further 30% decrease). Although antioxidant vitamins and peroxides modified the hepatic redox status, they did not influence bile flow. Although the composition of parenteral nutrition affects bile flow and the hepatic redox status, the oxidant-antioxidant imbalance in infused solutions is not the causal event in the installation of cholestasis.

Determination of Fe(II) and Zn(II) by spectrophotometry, atomic absorption spectrometry and ions chromatography methods in Vitrum R

Metrian [3-mercapto-5-(2′-hydroxynaphtylazo-1′)-1,2,4-triazole]; Metriap [3-mercapto-5-(3′,4′-dihydroxyphenylazo-1′)-1,2,4-triazole]; Metriarez-γ [3-mercapto-5-(2′,4′-dihydroxy-3′-caroboxyphenylazo-1′)-1,2,4-triazole] and Metidarez-β [2-mercapto-5-(2′,4′-dihydroxy-5′-carboxyphenylazo-1′)-1,3,4-thiadiazole]-reagents were synthesized on Faculty of Pharmacy, Medical University of Lublin and used for the determination by different analytical methods of milligram quantities of Fe(II) and Zn(II) occurring together in pharmaceutical preparations, both multivitamin preparations and those containing microelements. The determination results of classical spectrophotometry (D 0), spectrophotometry of derivatives (D 1 and D 2), atomic absorption spectrometric (AAS) and ions chromatography (IC) were analyzed statistically and compared with declared amount. The advantages of the proposed method of Fe(II) and Zn(II) determination include it's excellent precision and reproducibility of results.

Coadministration of Gatifloxacin and Multivitamin Preparation Containing Minerals: Potential Treatment Failure in an Elderly Patient

To report a case of probable treatment failure in a patient receiving gatifloxacin and a multivitamin preparation containing minerals. A 77-year-old white woman was prescribed gatifloxacin for hospital-acquired bacterial pneumonia. She was also receiving calcium carbonate 500 mg twice daily and a multivitamin preparation containing minerals once a day. Three days after gatifloxacin was started, the patient was still febrile, coughing, and not responding clinically. It was noted that nurses were administering the gatifloxacin tablet at the same time as the multivitamin tablet. The time of administration for gatifloxacin was changed to 6 hours after the patient received her multivitamin preparation. Two days later, she clinically improved. Studies have shown that the bioavailability of gatifloxacin is decreased with concurrent administration of antacids containing aluminum or magnesium; dietary supplements containing zinc, magnesium, and iron; multivitamin preparations containing minerals; and sucralfate. An objective causality assessment revealed that the adverse drug effect was probable. This case illustrates the need to recognize this potential interaction and to know how to avoid possible treatment failure.

Zinc status of lactating Egyptian mothers and their infants: effect of maternal zinc supplementation

In this study, assessment of serum, breast milk, and hair and nail zinc (Zn) was done in 60 primiparous women and their neonates to evaluate the effect of maternal Zn supplementation on maternal and infant Zn stores and on the infants' physical growth. Thirty mothers were given a multivitamin preparation (lacking Zn) and the other 30 were additionally supplied with Zn for 2 months, then reassessment of Zn levels was done. The results revealed diurnal variation in colostral Zn concentrations. Lactation depleted the maternal Zn stores whereas infant stores were replenished regardless of maternal supplementation. Zn supplementation caused significantly higher maternal hair, nail, and breast milk Zn levels but did not affect the infants' levels or their growth. In conclusion, Zn supplementation for lactating women positively influenced breast milk Zn concentrations and maternal body stores although it had no significant influence on the infants' physical growth. Women who plan to nourish their infants by breast milk alone should ask for dietary consultation to obtain this nutrient from a varied balanced diet rather than from supplementation. In addition, the evident diurnal variation in breast milk Zn emphasizes that working mothers should be advised to express their morning milk, which is richer in Zn, for the maximum benefit of their infants.

RP-HPLC determination of vitamins, folic acid and B12 in multivitamin tablets

A simple and sensitive reversed-phase, ion-pair HPLC method was developed and validated for the simultaneous determination of B-group vitamins, thiamine chloride hydrochloride (B1), nicotinamide (B3), pyridoxine hydrochloride (B6) and folic acid in Pentovit? coated tablets. The cyanocobalamine (B12) was determined separately, because of its low concentration in the investigated multivitamin preparation. RP-HPLC analysis was per- formed with a LKB 2150 HPLC system, equipped with a UV/VIS Waters M 484 detector. The procedures for the determination of B1, B2, B6 and folic acid were carried out on a Supelcosil ABZ+ (15 cm 4.6 mm; 5 m) column with methanol-5mM heptanesulphonic acid sodium salt 0.1 % triethylamine TEA (25:75 V/V); pH 2.8 as the mobile phase. For the determination of B12 a Suplex pKb-100 (15 cm 4.6 mm; 5 m) column and methanol?water (22:78 V/V) as the mobile phase were used. The column effluents were monitored at 290 nm for B1, B3, B6 and folic acid, and at 550 nm for B12. The obtained results and statistical parameters for all the investigated vitamins of the B-group in Pentovit? coated tablets were satisfactory and ranged from 90.4 % to 108.5 % (RSD. from 0.5 % to 4.1 %). The parameters for the validation of the methods are given.

Urinary Oxalate Excretion Increases in Home Parenteral Nutrition Patients on a Higher Intravenous Ascorbic Acid Dose

Vitamin C can be metabolized to oxalate. Case reports have suggested an association between IV vitamin C and urinary oxalate excretion. Recently, the US Food and Drug Administration required the dose of vitamin C in IV multivitamin preparations to be increased from 100 mg to 200 mg/d. We compared the urinary oxalate excretion level in stable home total parenteral nutrition (TPN) patients receiving both doses of vitamin C. Each participant provided a 24-hour urine sample for oxalate determination on the vitamin C dose (100 mg/d), and again after at least 1 month on the increased vitamin C dose (200 mg/d). A 2-day diet diary was completed covering the day before and the day of the urine collection and was analyzed for oxalate and vitamin C content. Comparisons were made using Student paired t test and Wilcoxon signed rank. Thirteen patients (7 males/6 females) aged 63.1 +/- 12.2 years who had no history of nephrolithiasis and had received TPN for 55.9 +/- 78.8 months were enrolled. The most common indication for TPN was short bowel syndrome (38.5%). Eight patients had an intact colon. Urinary oxalate excretion increased on the 200-mg vitamin C dose, from 0.34 +/- 0.13 to 0.44 +/- 0.17 mmol/d (mean increase = 0.10 mmol/d; p = .04; 95% confidence interval 0.004 to 0.19 mmol/d). Oral intake of vitamin C and oxalate did not differ between the 2 collection periods. In therapeutically used doses, IV vitamin C increases urinary oxalate excretion, potentially predisposing susceptible individuals to nephrolithiasis. This factor should be considered in patients receiving home TPN.

Vitamins for preterm infants

Providing adequate nutrition for preterm infants is a challenge, and ensuring optimal intake of vitamins is one important element of nutritional management. Preterm babies have different phases of nutrition and growth: a transitional phase (mainly parenteral nutrition), an early growth phase (enteral nutrition), and a longer period of catch-up growth (also enteral nutrition). Specific vitamin requirements differ according to dietary nutrient intake at each phase, and supplements must be tailored accordingly. As well as their nutritional role, there has been an interest in the use of vitamins as ‘pharmacological’ agents, particularly vitamins A and E as anti-oxidants. In this article, we will review the current evidence for nutritional use of multivitamin preparations, both for parenteral and enteral nutrition of preterm babies, as well as the potential pharmacological roles for vitamins A and E in reduction of oxygen-radical-induced injury.

Sequential injection spectrophotometric determination of iron as Fe(II) in multi-vitamin preparations using 1,10-phenanthroline as complexing agent

A sequential injection analysis (SIA) system is proposed for the determination of iron (II). Fe(II) was determined by SIA based on the reaction between 1,10-phenanthroline and iron (II), yielding an orange–red colour complex with absorption maximum at 512 nm. The method involved aspiration of 187 μl sample/standard zone followed by a zone of a reagent solution containing 140 μl of 7.8 × 10 −4 mol l −1 1,10-phenanthroline into a carrier stream to be stacked inside a holding coil and flow reversed through a reaction coil to a detector. The optimum condition was evaluated and the calibration curve is linear over a range of 0.25 to 5.0 mg l −1 of Fe(II) with detection limit of 18 μg l −1. A sample throughput of 40 h −1 was established. This technique is found to be simple, accurate, reproducible and sensitive. The proposed method was successfully applied for the determination of total iron as Fe(II) in pharmaceutical products (multi-vitamin tablets) and is especially useful for the determination of iron (II) in tablets with lower iron (II) contents. The results were found to be in good agreement with the results obtained by manual UV/Vis spectrophotometry and flame atomic absorption spectrometry (FAAS) and with claimed values by the manufacturers.

Interaction between ascorbate and light-exposed riboflavin induces lung remodeling.

Light-exposed parenteral multivitamins induce in lungs peroxide-like oxidant responses as well as the initiation of fibrosis. We hypothesized that peroxides generated in light-exposed total parenteral nutrition (TPN) affect lung remodeling. The objective was to assess the specific roles of peroxides, multivitamin preparation (MVP), and light exposure on lung remodeling during TPN. Three-day-old guinea pigs fitted with an indwelling catheter were assigned to the following intravenous regimens: TPN or MVP +/- photoprotection, H(2)O(2)+/- glutathione, MVP +/- metabisulfite, or ascorbic acid +/- riboflavin. Fed animals served as controls. After 4 days, lungs were sampled to determine alveolarization (intercepts), beta-actin mRNA (protection assay), and apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling). Data were analyzed by analysis of variance. The infusion of light-exposed multivitamins induced a 20% lower (p < 0.01) alveolarization index than fed controls, and 3-fold higher (p < 0.01) apoptotic events. This was prevented by photoprotecting TPN. The effect of multivitamins on the alveolarization index was reproduced (p < 0.05) by infusion of light-exposed riboflavin in the presence of vitamin C. The alveolarization index correlated (r(2) = 0.35; p < 0.05) with beta-actin mRNA, suggesting alveolar disruption. Antiperoxides conferred no protection against decreased alveolarization. Lung remodeling induced by exposure of TPN to ambient light is not due to a direct effect of infused peroxides but rather to an interaction between vitamin C and peroxides generated by the exposure of riboflavin to light. It is speculated that this interaction may play a role in the development of chronic lung disease of premature infants who receive TPN and have immature antioxidant defenses.

A modified vitamin regimen for vitamin B2, A, and E administration in very-low-birth-weight infants.

Very-low-birth-weight (VLBW; birth weight, <1,500 g) infants receive preterm infant formulas and parenteral multivitamin preparations that provide more riboflavin (vitamin B2) than does human milk and more than that recommended by the American Society of Clinical Nutrition. VLBW infants who are not breast-fed may have plasma riboflavin concentrations up to 50 times higher than those in cord blood. The authors examined a vitamin regimen designed to reduce daily riboflavin intake, with the hypothesis that this new regimen would result in lower plasma riboflavin concentrations while maintaining lipid-soluble vitamin levels. Preterm infants with birth weight < or =1,000 g received either standard preterm infant nutrition providing 0.42 to 0.75 mg riboflavin/kg/day (standard group), or a modified regimen providing 0.19 to 0.35 mg/kg/day (modified group). The modified group parenteral vitamin infusion was premixed in Intralipid. Enteral feedings were selected to meet daily riboflavin administration guidelines. Plasma riboflavin, vitamin A, and vitamin E concentrations were measured weekly by high-performance liquid chromatography. Data were analyzed with the independent t test, chi, and analysis of variance. The 36 infants (17 standard group, 19 modified group) had birth weight and gestational age of 779 +/- 29 g and 25.5 +/- 0.3 weeks (mean +/- SEM) with no differences between groups. Modified group infants received 38% less riboflavin (0.281 +/- 0.009 mg/kg/day), 35% more vitamin A (318.3 +/- 11.4 microg/kg/day), and 14% more vitamin E (3.17 +/- 0.14 mg/kg/day) than standard group infants. Plasma riboflavin rose from baseline in both groups but was 37% lower in the modified group during the first postnatal month (133.3 +/- 9.9 ng/mL). Riboflavin intake and plasma riboflavin concentrations were directly correlated. Plasma vitamin A (0.222 +/- 0.022 microg/mL) and vitamin E (22.26 +/- 1.61 /mL) concentrations were greater in the modified group. The modified vitamin regimen resulted in reduced riboflavin intake and plasma riboflavin concentration, suggesting plasma riboflavin concentration is partially dose dependent during the first postnatal month in VLBW infants. Modified group plasma vitamin A and vitamin E concentrations were greater during the first month, possibly because the vitamins were premixed with parenteral lipid emulsion. Because of the complexity of this protocol, the authors suggest that a parenteral multivitamin product designed for VLBW infants which uses weight-based dosing should be developed.

A Modified Vitamin Regimen for Vitamin B2, A, and E Administration in Very‐Low–Birth‐Weight Infants

ABSTRACTIntroduction:Very‐low–birth‐weight (VLBW; birth weight, &lt;1,500 g) infants receive preterm infant formulas and parenteral multivitamin preparations that provide more riboflavin (vitamin B2) than does human milk and more than that recommended by the American Society of Clinical Nutrition. VLBW infants who are not breast‐fed may have plasma riboflavin concentrations up to 50 times higher than those in cord blood. The authors examined a vitamin regimen designed to reduce daily riboflavin intake, with the hypothesis that this new regimen would result in lower plasma riboflavin concentrations while maintaining lipid‐soluble vitamin levels.Methods:Preterm infants with birth weight ≤1,000 g received either standard preterm infant nutrition providing 0.42 to 0.75 mg riboflavin/kg/day (standard group), or a modified regimen providing 0.19 to 0.35 mg/kg/day (modified group). The modified group parenteral vitamin infusion was premixed in Intralipid®. Enteral feedings were selected to meet daily riboflavin administration guidelines. Plasma riboflavin, vitamin A, and vitamin E concentrations were measured weekly by high‐performance liquid chromatography. Data were analyzed with the independent t test, χ2, and analysis of variance.Results:The 36 infants (17 standard group, 19 modified group) had birth weight and gestational age of 779 ± 29 g and 25.5 ± 0.3 weeks (mean ± SEM) with no differences between groups. Modified group infants received 38% less riboflavin (0.281 ± 0.009 mg/kg/day), 35% more vitamin A (318.3 ± 11.4 μg/kg/day), and 14% more vitamin E (3.17 ± 0.14 mg/kg/day) than standard group infants. Plasma riboflavin rose from baseline in both groups but was 37% lower in the modified group during the first postnatal month (133.3 ± 9.9 ng/mL). Riboflavin intake and plasma riboflavin concentrations were directly correlated. Plasma vitamin A (0.222 ± 0.022 μg/mL) and vitamin E (22.26 ± 1.61 /mL) concentrations were greater in the modified group.Conclusions:The modified vitamin regimen resulted in reduced riboflavin intake and plasma riboflavin concentration, suggesting plasma riboflavin concentration is partially dose dependent during the first postnatal month in VLBW infants. Modified group plasma vitamin A and vitamin E concentrations were greater during the first month, possibly because the vitamins were premixed with parenteral lipid emulsion. Because of the complexity of this protocol, the authors suggest that a parenteral multivitamin product designed for VLBW infants which uses weight‐based dosing should be developed.

Light-induced byproducts of vitamin C in multivitamin solutions.

When solutions of multivitamin preparations (MVPs) are exposed to light, H(2)O(2) as well as organic peroxides are generated and the concentration of vitamin C decreases. The aim of this study was to determine, using mass spectrometry, whether the generation of oxidative byproducts of vitamin C, such as dehydroascorbate (DHA) and 2,3-diketogulonic acid (DKG), accounted for the reported decrease in ascorbic acid in MVPs exposed to light. Mass spectrometry was used to document the formation of byproducts of ascorbic acid in solutions containing a MVP, vitamin C + riboflavin, and vitamin C + H(2)O(2) + Fe(2+). The involvement of ascorbic acid and H(2)O(2) in the formation of organic peroxides was tested by measuring peroxide concentrations in solutions containing H(2)O(2) with or without ascorbic acid and with or without Fe(2+) before and after addition of catalase. The loss of ascorbic acid in photo-exposed MVPs was associated with the concomitant generation of byproducts different from DHA and DKG. Among them, one mass fingerprint was particularly observed with solutions of vitamin C + riboflavin exposed to ambient light as well as with the solution of vitamin C + H(2)O(2) + Fe(2+), suggesting a Fenton-like reaction. This fingerprint was associated with the formation of catalase-resistant peroxides. Exposure of MVPs to light leads to the rapid loss of ascorbic acid and generation of specific byproducts that differ from DHA and DKG. The conversion of vitamin C into byproducts could be of biological importance in accounting for the decrease in ascorbic acid concentrations and the generation of organic peroxides in light-exposed MVPs.

The prevalence of coagulation abnormalities in hospitalized patients receiving lipid-based parenteral nutrition.

Vitamin K is not a component of the multivitamin preparation added to parenteral nutrition (PN) solutions, and hospitalized patients receiving parenteral nutrition support are at risk of developing vitamin K deficiency. In this study, 84 consecutive patients receiving PN were followed up prospectively to determine the incidence of a raised international normalized ratio (INR). All patients received lipid in their PN, which contains approximately 30 microg of vitamin K/100 mL. Patients were followed up for the course of PN or up to 4 weeks if they needed longer total parenteral nutrition. A raised INR compared with baseline developed in 3.6% of patients. All elevations were mild, and no patients developed clinical bleeding. It may be unnecessary to routinely supplement patients with vitamin K if they are receiving a lipid emulsion containing significant amounts of vitamin K. For patients receiving warfarin therapy, it will be important for nutrition support services to be aware of the vitamin K content of the lipid emulsion they are using as patients receiving a multivitamin preparation containing vitamin K and lipid emulsion may receive increased amounts of vitamin K, which could lead to warfarin resistance.

Electrophoretic Behaviour of Biotin and Biocytin in Capillary Electrophoresis. Determination of Biotin in Pharmaceutical Formulations

The migration behaviour of biotin and biocytin was investigated by capillary zone electrophoresis (CZE). The results indicate that with a 50 mM borate buffer at pH 9.0 the separation is excellent. The CZE method can be applied to the determination of biotin in multi-vitamin preparations. However, for samples with a low biotin content, a micellar electrokinetic chromatography (MEKC) approach was developed in order to avoid the overlapping of the small peak of biotin with the large peaks of other vitamins. As electrophoretic electrolyte the MEKC method uses a solution containing 20 mM phosphate buffer (pH 7.5), 75 mM sodium dodecylsulphate and 30% (v/v) methanol. The performance of the method was tested in the analysis of two pharmaceutical preparations.