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

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.

Impurities in Hyaluronic Acid Dermal Fillers? A Narrative Review on Nonanimal Cross-Linked Fillers

Importance: Nonanimal cross-linked hyaluronic acid (HA) dermal fillers are among the most versatile tools in minimal invasive esthetic medicine. Filler injections aim to volumize, provide contour, and reduce wrinkles and skinfolds. In the hand of the experienced user, HA fillers have an excellent safety profile. Nevertheless, adverse events have been reported related to poor injection techniques, infection, and immune reactions. Observations: In this review, the focus is on filler impurities. Impurities can originate from the fermentation process, crosslinking, packaging, and contamination. Impurities consist of particular and nonparticular matter. We discuss possible risks for the patient to be treated with HA fillers. Conclusions and Relevance: Impurities of dermal fillers bear a potential risk for patients, such as delayed autoimmune and inflammatory reactions, biofilm formation, and exposure to leachable Endocrine Disrupting Chemicals. Amount and quality of impurities can be considered as one of the quality parameters of commercially fillers. Considering patient safety, filler impurities should be further reduced.

Etiology of Delayed Inflammatory Reaction Induced by Hyaluronic Acid Filler

The etiology and pathophysiology of delayed inflammatory reactions caused by hyaluronic acid fillers have not yet been elucidated. Previous studies have suggested that the etiology can be attributed to the hyaluronic acid filler itself, patient's immunological status, infection, and injection technique. Hyaluronic acid fillers are composed of high-molecular weight hyaluronic acids that are chemically cross-linked using substances such as 1,4-butanediol diglycidyl ether (BDDE). The mechanism by which BDDE cross-links the two hyaluronic acid disaccharides is still unclear and it may exist as a fully reacted cross-linker, pendant cross-linker, deactivated cross-linker, and residual cross-linker. The hyaluronic acid filler also contains impurities such as silicone oil and aluminum during the manufacturing process. Impurities can induce a foreign body reaction when the hyaluronic acid filler is injected into the body. Aseptic hyaluronic acid filler injections should be performed while considering the possibility of biofilm formation or delayed inflammatory reaction. Delayed inflammatory reactions tend to occur when patients experience flu-like illnesses; thus, the patient's immunological status plays an important role in delayed inflammatory reactions. Large-bolus hyaluronic acid filler injections can induce foreign body reactions and carry a relatively high risk of granuloma formation.

Application of Formulation Principles to Stability Issues Encountered During Processing, Manufacturing, and Storage of Drug Substance and Drug Product Protein Therapeutics

The field of formulation and stabilization of protein therapeutics has become rather extensive. However, most of the focus has been on stabilization of the final drug product. Yet, proteins experience stress and degradation through the manufacturing process, starting with fermentaition. This review describes how formulation principles can be applied to stabilize biopharmaceutical proteins during bioprocessing and manufacturing, considering each unit operation involved in prepration of the drug substance. In addition, the impact of the container on stabilty is discussed as well.

Toxic Metals and Metalloids in Infant Formulas Marketed in Brazil, and Child Health Risks According to the Target Hazard Quotients and Target Cancer Risk

Children are highly vulnerable to chemical exposure. Thus, metal and metalloid in infant formulas are a concern, although studies in this regard are still relatively scarce. Thus, the presence of aluminum, arsenic, cadmium, tin, mercury, lead, and uranium was investigated in infant formulas marketed in Brazil by inductively coupled plasma mass spectrometry, and the Target Hazard Quotients (THQ) and Target Cancer Risk (TCR) were calculated in to assess the potential risk of toxicity for children who consume these products continuously. Aluminum ranging from 0.432 ± 0.049 to 1.241 ± 0.113 mg·kg-1, arsenic from 0.012 ± 0.009 to 0.034 ± 0.006 mg·kg-1, and tin from 0.007 ± 0.003 to 0.095 ± 0.024 mg·kg-1 were the major elements, while cadmium and uranium were present at the lowest concentrations. According to the THQ, arsenic contents in infant formulas showed a THQ > 1, indicating potential health risk concerns for newborns or children. Minimal carcinogenic risks were observed for the elements considered carcinogenic. Metabolic and nutritional interactions are also discussed. This study indicates the need to improve infant formula surveillance concerning contamination by potentially toxic and carcinogenic elements.

Determination of aluminum concentrations of parenteral nutrition solutions by HPLC

Aluminum (Al) contamination of parenteral nutrition (PN) solutions has been known for over 30 years. In particular, vascular intake of Al leads to its accumulation in tissues. In this study, 8 all-in-one PN solutions the aluminum concentration was analyzed by high-performance liquid chromatography. The mean Al concentration of the glucose solutions of the PN solutions combinations was 16.36 ± 8.31 µg/L, the mean Al concentration of the amino acid solutions was 4.96 ± 3.73 µg/L, and the mean Al concentration of the lipid solutions was 9.09 ± 11.23 µg/L. The Al concentration of the PN₅ glucose and PN₂ lipid solutions were above 25 µg/L, which is the limit set by the Food and Drug Administration (FDA). No studies in the literature have examined the Al concentrations of all-in-one PN solutions via HPLC. In two of the analyzed solutions, the Al concentration was found to be higher than the limit set by the FDA.

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.

Calcium and Phosphorous in Pediatric Parenteral Nutrition

Calcium (Ca) and phosphorus (P) are essential for various systemic functions, including bone mineralization. Adequate provision of Ca and P in pediatric parenteral nutrition (PN) solutions is necessary for skeletal growth and for the prevention of metabolic bone disease. The provision of adequate doses of Ca and P in pediatric PN solutions is complicated by the increased needs in preterm and term infants, solubility limitations, and venous access. Clinicians should be aware of the evidence that supports the optimal use of Ca and P in pediatric PN solutions, including studies that have evaluated dosing and solubility. The aim of this article is to review relevant literature and practices for the use of these two minerals in pediatric PN solutions. The vitamin D endocrine system, a critical component for Ca homeostasis and bone mineralization, is discussed, as well as clinical manifestations of metabolic bone disease and methods for its prevention, assessment, and treatment in pediatric patients receiving PN.

Silicon Reverses Lipid Peroxidation but not Acetylcholinesterase Activity Induced by Long-Term Exposure to Low Aluminum Levels in Rat Brain Regions

Aluminum (Al) is the most widely distributed metal in the environment and is extensively used in daily life leading to easy exposure to human beings. Besides not having a recognized physiological role, Al may produce adverse effects through the interaction with the cholinergic system contributing to oxidative stress. The present study evaluated, in similar conditions of parenteral nutrition, whether the reaction of silicon (SiO2) with Al(3+) to form hydroxyaluminosilicates (HAS) reduces its bioavailability and toxicity through intraperitoneal administrations of 0.5 mg Al/kg/day and/or 2 mg Si/kg/day in Wistar rats. Al and Si concentrations were determined in rat brain tissue and serum. Acetylcholinesterase (AChE) activity and lipid peroxidation (LPO) were analyzed in the cerebellum, cortex, hippocampus, striatum, hypothalamus, and blood. An increase in the Al concentration was verified in the Al + Si group in the brain. All the groups demonstrated enhanced Si compared to the control animals. Al(3+) increased LPO measured by thiobarbituric acid reactive substances (TBARS) in cerebellum and hippocampus, whereas SiO2 reduced it when compared with the control group. An increase of AChE activity was observed in the Al-treated group in the cerebellum whereas a decrease of this enzyme activity was observed in the cortex and hippocampus in the Al and Al + Si groups. Al and Si concentrations increased in rat serum; however, no effect was observed in blood TBARS levels and AChE activity. SiO2 showed a protective effect in the hippocampus and cerebellum against cellular damage caused by Al(3+)-induced lipid peroxidation. Thus, SiO2 may be considered an important protector in LPO induced by Al(3+).

A Filtration System That Greatly Reduces Aluminum in Calcium Gluconate Injection, USP Used to Prepare Parenteral Nutrition Solutions

OBJECTIVE

The study objective was to reduce aluminum (Al) in Calcium Gluconate Injection, US Pharmacopeia (USP) used in the preparation of parenteral nutrition (PN) solutions.

METHODS

A flow-through filter containing an immobilized chelator that complexes Al from Calcium Gluconate Injection, USP as it flows through the filter was designed, refined by design modifications, and extensively tested. When a small-volume parenteral vial containing 100 mL of Calcium Gluconate Injection, USP is connected on the inlet side of the filter, and the outlet side is connected to an evacuated receiving vial, the filtered solution is drawn into the receiving vial. This constitutes a complete system to remove Al from Calcium Gluconate Injection, USP.

RESULTS

The extent of Al removal is flow rate dependent. At a flow rate of 1 mL/min approximately 85% of the Al was removed from calcium gluconate solution. PN solutions have been reported to deliver 15 to 23 mcg/kg/day Al to neonates. Given that Calcium Gluconate Injection, USP provides 85% of the Al in neonatal PN solutions, removal of 85% of the Al from this source was calculated to reduce Al delivered to most neonates to <5 mcg/kg/day.

CONCLUSIONS

A point-of-use, self-contained, single-use, disposable, Al-complexing filter has been created. It was calculated to reduce Al delivered in PN solutions by 72%, resulting in daily Al delivery below the level that results in Al accumulation associated with central nervous system and bone toxicity to all but the smallest (<1 kg) infants.

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.

Assessing the potential impact of non-proprietary drug copies on quality of medicine and treatment in patients with relapsing multiple sclerosis: the experience with fingolimod

Background

Fingolimod is a once-daily oral treatment for relapsing multiple sclerosis, the proprietary production processes of which are tightly controlled, owing to its susceptibility to contamination by impurities, including genotoxic impurities. Many markets produce nonproprietary medicines; assessing their efficacy and safety is difficult as regulators may approve nonproprietary drugs without bioequivalence data, genotoxic evaluation, or risk management plans (RMPs). This assessment is especially important for fingolimod given its solubility/bioavailability profile, genotoxicity risk, and low-dose final product (0.5 mg). This paper presents an evaluation of the quality of proprietary and nonproprietary fingolimod variants.

Methods

Proprietary fingolimod was used as a reference substance against which eleven nonproprietary fingolimod copies were assessed. The microparticle size distribution of each compound was assessed by laser light diffraction, and inorganic impurity content by sulfated ash testing. Heavy metals content was quantified using inductively coupled plasma optical emission spectrometry, and levels of unspecified impurities by high-performance liquid chromatography. Solubility was assessed in a range of solvents at different pH values. Key information from the fingolimod RMP is also presented.

Results

Nonproprietary fingolimod variants exhibited properties out of proprietary or internationally accepted specifications, including differences in particle size distribution and levels of impurities such as heavy metals. For microparticle size and heavy metals, all tested fingolimod copies were out-of-specification by several-fold magnitudes. Proprietary fingolimod has a well-defined RMP, highlighting known and potential mid- to long-term safety risks, and risk-minimization and pharmacovigilance procedures.

Conclusion

Nonproprietary fingolimod copies produced by processes less well controlled than or altered from proprietary production processes may reduce product reproducibility and quality, potentially presenting risks to patients. Safety data and risk-minimization strategies for proprietary fingolimod may not apply to the nonproprietary fingolimod copies evaluated here. Market authorization of nonproprietary fingolimod copies should require an appropriate RMP to minimize risks to patients.

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.

Evidence for aluminum-binding erythropoietin by size-exclusion chromatography coupled to electrothermal absorption atomic spectrometry

Erythropoietin (EPO) is a glycoprotein that stimulates erythropoiesis and is clinically used for treating anemia during chronic renal failure and for anemia in preterm infants. EPO formulations usually have elevated rates of contamination due to aluminum (Al), which is toxic to both types of patients. Size-exclusion chromatography (SEC) coupled with graphite furnace atomic absorption spectrometry (GF AAS) was employed to separate proteins and to quantify the amount of aluminum present in the elution volume corresponding to EPO and, therefore, to evaluate possible binding. Because EPO formulations contain human serum albumin (HSA), a chromatographic method was optimized for the separation of these proteins. Subsequent to the chromatographic separation, 1-mL fractions of the column effluent were collected, and the Al content in these aliquots was measured by GF AAS. EPO and HSA samples were incubated with Al for 4h at 4°C and 37°C as well as for 16 h at 4°C and 37°C. Afterwards, they were injected into the chromatographic system. These samples were also submitted to ultrafiltration (10 and 50 kDa membranes), and Al was measured in the ultrafiltrates. The results showed that Al was present in the eluent volume corresponding to the EPO peak but not in the HSA peak in the chromatograms. Temperature strengthened the interaction because the Al present in the EPO fraction was 3 times higher at 37°C compared to 4°C. Thirty-eight percent of the Al present in a 2.4 μg/mL EPO standard solution, and approximately 50% of the Al in formulation samples containing approximately 11 μg/mL EPO and either citrate or phosphate, were non-ultrafiltrable, which suggests that EPO is an effective Al acceptor in vitro.

Enzyme stabilization by glass-derived silicates in glass-exposed aqueous solutions

OBJECTIVES

To analyze the solutes leaching from glass containers into aqueous solutions, and to show that these solutes have enzyme activity stabilizing effects in very dilute solutions.

METHODS

Enzyme assays with acetylcholine esterase were used to analyze serially succussed and diluted (SSD) solutions prepared in glass and plastic containers. Aqueous SSD preparations starting with various solutes, or water alone, were prepared under several conditions, and tested for their solute content and their ability to affect enzyme stability in dilute solution.

RESULTS

We confirm that water acts to dissolve constituents from glass vials, and show that the solutes derived from the glass have effects on enzymes in the resultant solutions. Enzyme assays demonstrated that enzyme stability in purified and deionized water was enhanced in SSD solutions that were prepared in glass containers, but not those prepared in plastic. The increased enzyme stability could be mimicked in a dose-dependent manner by the addition of silicates to the purified, deionized water that enzymes were dissolved in. Elemental analyses of SSD water preparations made in glass vials showed that boron, silicon, and sodium were present at micromolar concentrations.

CONCLUSIONS

These results show that silicates and other solutes are present at micromolar levels in all glass-exposed solutions, whether pharmaceutical or homeopathic in nature. Even though silicates are known to have biological activity at higher concentrations, the silicate concentrations we measured in homeopathic preparations were too low to account for any purported in vivo efficacy, but could potentially influence in vitro biological assays reporting homeopathic effects.

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.

Measured versus estimated aluminum content of parenteral nutrient solutions

PURPOSE

A study was conducted to directly measure the aluminum concentration in a select number of parenteral nutrient (PN) solutions and to compare this value with the calculated dose using the concentrations reported by the manufacturer.

METHODS

Fifty 2.5-mL samples were prepared for analysis and were obtained from PN solutions prepared for adult and pediatric/neonatal patients. Intravenous large-volume parenterals were used as controls. Samples were sent to two different reference laboratories. Batch 1 included 26 samples, 22 from PN solutions, 1 control, and 3 paired (duplicate) samples selected from the 22 PN bags. Because 8 of the samples were lost to analysis, a second batch of samples was included. Batch 2 consisted of 24 samples from 4 PN solutions and 2 controls. Batch 2 was composed of four aliquots from each solution that were divided equally and sent to the two laboratories.

RESULTS

Twenty-three values were used in the statistical analysis. The results showed that only two of the adult PN solutions equaled or exceeded the threshold set by the Food and Drug Administration (FDA) for measured aluminum exposure. The measured concentration of aluminum for all six of the pediatric and neonatal solutions met or exceeded the FDA threshold; however, this value was much lower than what had been estimated using the labeled aluminum concentration at expiry.

CONCLUSION

In PN solutions expected to have a moderately high concentration of aluminum, the measured amount of aluminum was far less than the amount that would be estimated by calculation using the labeled concentrations of aluminum in each of the ingredients.

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.

Recent developments in aluminium contamination of products used in parenteral nutrition

PURPOSE OF REVIEW

This review evaluates recent developments concerning aluminium contamination of products used in the preparation of parenteral nutrition solutions and the failure of the pharmaceutical industry to respond to these concerns. The difficulty in meeting the intent of the recent US Food and Drug Administration mandate to reduce aluminium exposure with currently available parenteral nutrition additives is addressed. This review also summarizes the issues associated with aluminium toxicity, the patient populations at risk, treatment options, and compounding considerations.

RECENT FINDINGS

Unfortunately, the published literature detailing the toxicities seen from aluminium exposure in the parenteral nutrition patient are primarily limited to those published in the 1980s and 1990s. Recent publications refer back to these classic papers and discuss the challenges that practitioners face when trying to apply the recommendations of the recently implemented Food and Drug Administration mandate with outdated literature. Few studies have been published to validate those earlier findings.

SUMMARY

The issues surrounding aluminium toxicity are real and must be addressed. In order to make meaningful changes in clinical practice, low aluminium parenteral nutrition additives are needed and studies must be conducted using currently available products. It remains a challenge to optimize nutritional intake from parenteral nutrition and at the same time reduce aluminium exposure.

Development of a thermogelling ophthalmic formulation of cysteine

Preliminary studies carried out with cysteine 2% solution showed that pH adjusted to isoelectrical pH (i.e., 4.9) led to enhance stability during autoclaving and ensured no significant degradation during at least 14 days if stored at 2-8 degrees C protected from light. Optimized formulations combined either cysteine(2%)/Poloxamer407(16.5%) or cysteine(2%)/Poloxamer407(20%)/Poloxamer188(5%) and were characterized by an adequate temperature of gelification (TG) (25.9 degrees C and 26.9 degrees C, respectively), an important gel strength (5.1daN and 5.3daN, respectively) and a drastic increase in the apparent viscosity between 24 degrees C and 32 degrees C (multiplication factor of 78 and 77-fold, respectively). Cysteine addition produced only slight but significant decrease in temperature of gelification and increase in gel strength.