Influence of the glass packing on the contamination of pharmaceutical products by aluminium. Part II: amino acids for parenteral nutrition

Interference of Parenteral Nutrition Components in Silicon-Mediated Protection Against Aluminum Bioaccumulation

Aluminum and silicon are contaminants found in formulations used to prepare parenteral nutrition. Both elements are leached from glass containers, mainly during the heating cycle for sterilization. Insoluble and biologically inactive species of hydroxyaluminosilicates have been shown to form in solutions containing Al and Si. Therefore, this interaction may play an important role in protecting the body against Al toxicity. In this study, the bioavailability of Al in the presence of Si, calcium gluconate (Gluc.), and potassium phosphate (Phosf.) was investigated in rats. The rats were divided into 10 groups of 5 animals each: control, Al, Si, Al + Si, Gluc, Gluc + Al, Gluc + Al + Si, Phosf, Phosf + Al, and Phosf + Al + Si. The doses, consisting of 0.5 mg/kg/day Al and 2 mg/kg/day Si in the presence or absence of Gluc. or Phosf., were intraperitoneally administered for 3 months. Tissues were analyzed for Al and Si content. Al accumulated in the liver, kidneys, and bones, and the simultaneous administration of Si decreased Al accumulation in these tissues. The presence of Si reduced the amount of Al present by 72% in the liver, by 45% in the kidneys, and by 16% in bone. This effect was lees pronounced in the presence of parenteral nutrition compounds though. Si tissue accumulation was also observed, mainly when administered together with phosphate. These results suggest that Si may act as a protector against Al toxicity, by either reducing Al absorption or increasing its excretion, probably through hydroxyaluminosilicates formation. The presence of calcium gluconate and potassium phosphate decreases or inhibits this effect.

Aluminum Exposure from Parenteral Nutrition: Early Bile Canaliculus Changes of the Hepatocyte

Background: Neonates on long-term parenteral nutrition (PN) may develop parenteral nutrition-associated liver disease (PNALD). Aluminum (Al) is a known contaminant of infant PN, and we hypothesize that it substantially contributes to PNALD. In this study, we aim to assess the impact of Al on hepatocytes in a piglet model. Methods: We conducted a randomized control trial using a Yucatan piglet PN model. Piglets, aged 3–6 days, were placed into two groups. The high Al group (n = 8) received PN with 63 µg/kg/day of Al, while the low Al group (n = 7) received PN with 24 µg/kg/day of Al. Serum samples for total bile acids (TBA) were collected over two weeks, and liver tissue was obtained at the end of the experiment. Bile canaliculus morphometry were studied by transmission electron microscopy (TEM) and ImageJ software analysis. Results: The canalicular space was smaller and the microvilli were shorter in the high Al group than in the low Al group. There was no difference in the TBA between the groups. Conclusions: Al causes structural changes in the hepatocytes despite unaltered serum bile acids. High Al in PN is associated with short microvilli, which could decrease the functional excretion area of the hepatocytes and impair bile flow.

Aluminum and Phthalates in Calcium Gluconate: Contribution From Glass and Plastic Packaging

BACKGROUND

Aluminum contamination of parenteral nutrition solutions has been documented for 3 decades. It can result in elevated blood, bone, and whole body aluminum levels associated with neurotoxicity, reduced bone mass and mineral content, and perhaps hepatotoxicity. The primary aluminum source among parenteral nutrition components is glass-packaged calcium gluconate, in which aluminum concentration in the past 3 decades has averaged approximately 4000 μg/L, compared with <200 μg/L in plastic container-packaged calcium gluconate. A concern about plastic packaging is leaching of plasticizers, including phthalates, which have the potential to cause endocrine (male reproductive system) disruption and neurotoxicity.

METHODS

Aluminum was quantified in samples collected periodically for more than 2 years from 3 calcium gluconate sources used to prepare parenteral nutrition solutions; 2 packaged in glass (from France and the United States) and 1 in plastic (from Germany); in a recently released plastic-packaged solution (from the United States); and in the 2 glass containers. Phthalate concentration was determined in selected samples of each product and leachate of the plastic containers.

RESULTS

The initial aluminum concentration was approximately 5000 μg/L in the 2 glass-packaged products and approximately 20 μg/L in the plastic-packaged product, and increased approximately 30%, 50%, and 100% in 2 years, respectively. The aluminum concentration in a recently released Calcium Gluconate Injection USP was approximately 320 μg/L. Phthalates were not detected in any calcium gluconate solutions or leachates.

CONCLUSIONS

Plastic packaging greatly reduces the contribution of aluminum to parenteral nutrition solutions from calcium gluconate compared with the glass-packaged product.

Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts

Abstract Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007) . Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of "total Al"assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al(+3) to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)(+2) and Al(H2O)6 (+3)] that after complexation with O2(•-), generate Al superoxides [Al(O2(•))](H2O5)](+2). Semireduced AlO2(•) radicals deplete mitochondrial Fe and promote generation of H2O2, O2 (•-) and OH(•). Thus, it is the Al(+3)-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer's disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances.

Aluminum exposure in neonatal patients using the least contaminated parenteral nutrition solution products

Aluminum (Al) is a contaminant in all parenteral nutrition (PN) solution component products. Manufacturers currently label these products with the maximum Al content at the time of expiry. We recently published data to establish the actual measured concentration of Al in PN solution products prior to being compounded in the clinical setting [1]. The investigation assessed quantitative Al content of all available products used in the formulation of PN solutions. The objective of this study was to assess the Al exposure in neonatal patients using the least contaminated PN solutions and determine if it is possible to meet the FDA “safe limit” of less than 5 μg/kg/day of Al. The measured concentrations from our previous study were analyzed and the least contaminated products were identified. These concentrations were entered into our PN software and the least possible Al exposure was determined. A significant decrease (41%–44%) in the Al exposure in neonatal patients can be achieved using the least contaminated products, but the FDA “safe limit” of less than 5 μg/kg/day of Al was not met. However, minimizing the Al exposure may decrease the likelihood of developing Al toxicity from PN.

Aluminum in pediatric parenteral nutrition products: measured versus labeled content

OBJECTIVE

Aluminum is a contaminant in all parenteral nutrition solutions. Manufacturers currently label these products with the maximum aluminum content at the time of expiry, but there are no published data to establish the actual measured concentration of aluminum in parenteral nutrition solution products prior to being compounded in the clinical setting. This investigation assessed quantitative aluminum content of products commonly used in the formulation of parenteral nutrition solutions. The objective of this study is to determine the best products to be used when compounding parenteral nutrition solutions (i.e., those with the least amount of aluminum contamination).

METHODS

All products available in the United States from all manufacturers used in the production of parenteral nutrition solutions were identified and collected. Three lots were collected for each identified product. Samples were quantitatively analyzed by Mayo Laboratories. These measured concentrations were then compared to the manufacturers' labeled concentration.

RESULTS

Large lot-to-lot and manufacturer-to-manufacturer differences were noted for all products. Measured aluminum concentrations were less than manufacturer-labeled values for all products.

CONCLUSIONS

The actual aluminum concentrations of all the parenteral nutrition solutions were significantly less than the aluminum content based on manufacturers' labels. These findings indicate that 1) the manufacturers should label their products with actual aluminum content at the time of product release rather than at the time of expiry, 2) that there are manufacturers whose products provide significantly less aluminum contamination than others, and 3) pharmacists can select products with the lowest amounts of aluminum contamination and reduce the aluminum exposure in their patients.

Aluminum content of parenteral nutrition in neonates: measured versus calculated levels

BACKGROUND AND OBJECTIVE

Aluminum (Al) is associated with significant central nervous system toxicity and bone and liver damage. Because Al is a contaminant of parenteral nutrition (PN) components including calcium and phosphate additives, premature infants are at potentially high risk for toxicity. The US Food and Drug Administration (FDA) has mandated PN component product labeling and recommended maximum Al daily exposure limits. The objective of this article is to determine the actual Al content of neonatal PN solutions, compare these values to the calculated amounts from manufacturers' PN product labels, and ascertain whether the actual Al exposure exceeds the FDA recommended maximum of 5 microg . kg(-1) . day(-1).

MATERIALS AND METHODS

Samples from 40 neonatal patient PN solutions were selected for sampling and Al content determination. Samples were also taken from 16 manufacturer's component products used in PN formulation. All of the samples were sent to Mayo Laboratories for Al content measurement. The calculated Al concentrations in PN samples were determined from the manufacturer's labeled content.

RESULTS

Both measured and calculated Al concentrations exceeded the FDA recommended safe limit of <5 microg . kg(-1) . day(-1). The actual measured Al content was significantly lower than the calculated Al content in both the patient PN solutions and the component product samples.

CONCLUSIONS

Al exposure exceeded the FDA recommended maximum limit for all patient samples; however, the actual measured Al content of all the samples was significantly less than the calculated Al content based on manufacturer's labels. These findings suggest that manufacturers label their products with actual Al content at the time of product release rather than at time of expiration. Periodic monitoring of Al levels should be considered with prolonged PN therapy. Changes in manufacturing processes, including the use of better raw materials, are essential to reduce Al contamination to meet FDA mandates.

Ion-exchange and potentiometric characterization of Al–cystine and Al–cysteine complexes

The interaction between aluminium and cysteine and cystine was evaluated by means of ion-exchange experiments and potentiometry. Ion-exchange experiments included other ligands with affinity for aluminium and two kinds of resins, either a Na+ -form or an Al3+ -form exchanger. The ability of the ligands to keep aluminium in solution in the presence of the Na+ exchanger or to withdraw it from the Al3+ -form resin was evaluated. Aluminium quantification was carried out by either graphite-furnace or flame atomic absorption spectrometry. Aluminium extraction isotherms were linearised using the Scatchard plot, and stability constants were obtained from the curves' slopes. The experiments showed that the ability of the ligands to withdraw aluminium from the Al3+ -form resin increased following the order cysteine < oxalate < citrate = cystine < nitrilotriacetic acid < ethylenediaminetetraacetic acid. Potentiometric titrations, carried out in aqueous solution with constant ionic strength and temperature, showed that the predominant species in solution have a metal-ligand proportion of 1:1 for both amino acids. The main species are Al(OH)3L, with log K of 6.2 for cysteine, and AlL and Al(OH)L, with log K of 10.3 and 1.7, respectively, for cystine. Stability constants obtained from the Scatchard plots showed a linear correlation with the stability constants obtained by potentiometry for cystine and cysteine in this work and those collected from the literature for the other ligands. These results show that cysteine and cystine extract and maintain aluminium in solution, which may explain elevated concentrations of aluminium in parenteral nutrition solutions containing these amino acids.

Arsenic release from glass containers by action of intravenous nutrition formulation constituents

Pharmacopoeias prescribe tests to determine the levels of arsenic in raw materials and glass containers. In this study, glass ampoules for injectables containing individually the main components of intravenous nutrition formulations were submitted to the hydrolytic resistance test by heating at 121 degrees C for 30 min. As(V) and As(III) levels in these solutions after heating were determined by hydride generation atomic absorption spectrometry. The arsenic content of substances used in these formulations was previously determined, as well as the arsenic content of the glass containers. The results showed that raw substances as well as glass containers contain arsenic. Moreover, arsenic is released during the heating (hydrolytic resistance test). However, the amount released and the arsenic species present in solution depend on the solution composition. While As(V) was the predominant specie in glass, solutions containing reducing substances such as glucose and vitamins had As(III) in higher concentration. Therefore, arsenic is released from glass containers during the heating for sterilization, and reacts with formulation constituents depending on their reducing properties.

Influence of the glass packing on the contamination of pharmaceutical products by aluminium. Part III: Interaction container-chemicals during the heating for sterilisation

The interaction of chemicals with the container materials during heating for sterilisation was investigated, storing the components of parenteral nutrition solutions individually in sealed glass ampoules and in contact with a rubber stopper, and heating the system at 121 degrees C for 30 min. Subsequently, the aluminium content of the solutions was measured by atomic absorption spectrometry (AAS). The assay was also carried out with acids, alkalis and some complexing agents for Al. The containers were decomposed and also assayed for aluminium. 30 different commercial solutions for parenteral nutrition, stored either in glass or in plastic containers, were assayed measuring the aluminium present in the solutions and in the container materials. The results of all investigated container materials revealed an aluminium content of 1.57% Al in glass, 0.05% in plastic and 4.54% in rubber. The sterilisation procedure showed that even pure water was able to extract Al from glass and rubber, 22.5 +/- 13.3 microg/L and 79.4 +/- 22.7 microg/L respectively, while from plastic the aluminium leached was insignificant. The Al released from glass ampoules laid between 20 microg/L for leucine, ornithine and lysine solutions and 1500 microg/L for solutions of basic phosphates and bicarbonate; from rubber stoppers it reached levels over 500 microg/L for cysteine, aspartic acid, glutamic acid and cystine solutions. Ion-exchange properties and influence of pH can explain the interaction of glass with some chemicals (salts, acids and alkalis), but only an affinity for aluminium could explain the action of some amino acids and other chemicals, as albumin and heparin, on glass and rubber, considering the aluminium release. Experiments with complexing agents for Al allowed to conclude that the higher the stability constant of the complex, the higher the Al release from the container material.