Ferrous iron content of intravenous iron formulations

An Analytical Method for Determination of Total Iron in Pharmaceuticalgrade Intravenous Iron Colloidal Complexes by Redox-Potentiometry

BACKGROUND

Iron carbohydrate complexes are colloidal dispersions made up of polynuclear Fe(III)-oxyhydroxide cores surrounded by a carbohydrate shell that stabilizes the complex in iron colloidal formulations. The current study provides an improved method that is precise, accurate, and linear for quantifying total iron in most Iron Carbohydrate Colloid Drug Products.

METHODS

Redox iodometry with a potentiometric determination is used to evaluate total iron in intravenous formulations. The visual indicator approach is more prone to fluctuations at endpoint calculations. Hence, the voltage potential approach is widely accepted as it is more accurate and sensitive. It tracks the actual change in activity that coincides with the equivalence point that is finally considered an endpoint. The principle is based on the idea that ferric iron in formulation reduces to ferrous iron in the presence of the iodide, which oxidizes to iodine. The released iodine is titrated using sodium thiosulfate.

RESULTS

The proposed method was precise, with %RSD (relative standard deviation) not more than 1. The method was linear between 80% and 120%, with a linear regression of 0.999. The percent recovery ranged from 98.20 to 99.98 for the concentration ranges of 80-120. The method's robustness was checked by various analysts using different reagent grades.

CONCLUSION

The proposed potentiometric determination method was precise, accurate, linear, and sensitive. The method was successfully validated, and the total iron content determined for commercial batches agrees with the iron claim on the label. Therefore, this method can be adapted widely for total iron content determination in any Intravenous formulation currently available on the market. The proposed method is more accessible at the Quality Control facilities on an industrial scale.

Progress and prospects of magnetic iron oxide nanoparticles in biomedical applications: A review

Nanoscience has been considered as one of the most substantial research in modern science. The utilization of nanoparticle (NP) materials provides numerous advantages in biomedical applications due to their unique properties. Among various types of nanoparticles, the magnetic nanoparticles (MNPs) of iron oxide possess intrinsic features, which have been efficiently exploited for biomedical purposes including drug delivery, magnetic resonance imaging, Magnetic-activated cell sorting, nanobiosensors, hyperthermia, and tissue engineering and regenerative medicine. The size and shape of nanostructures are the main factors affecting the physicochemical features of superparamagnetic iron oxide nanoparticles, which play an important role in the improvement of MNP properties, and can be controlled by appropriate synthesis strategies. On the other hand, the proper modification and functionalization of the surface of iron oxide nanoparticles have significant effects on the improvement of physicochemical and mechanical features, biocompatibility, stability, and surface activity of MNPs. This review focuses on popular methods of fabrication, beneficial surface coatings with regard to the main required features for their biomedical use, as well as new applications.

Incidence of Iron Deficiency and the Role of Intravenous Iron Use in Perioperative Periods

Iron deficiency is a major problem in worldwide populations, being more alarming in surgical patients. In the presence of absolute iron deficiency (depletion of body iron), functional iron deficiency (during intense bone marrow stimulation by endogenous or exogenous factors), or iron sequestration (acute or chronic inflammatory conditions), iron-restricted erythropoiesis can develop. This systemic review was conducted to draw attention to the delicate problem of perioperative anemia, and to provide solutions to optimize the management of anemic surgical patients. Systemic reviews and meta-analyses, clinical studies and trials, case reports and international guidelines were studied, from a database of 50 articles. Bone marrow biopsy, serum ferritin levels, transferrin saturation, the mean corpuscular volume, and mean corpuscular hemoglobin concentration were used in the diagnosis of iron deficiency. There are various intravenous iron formulations, with different pharmacological profiles used for restoring iron. In surgical patients, anemia is an independent risk factor for morbidity and mortality. Therefore, anemia correction should be rapid, with parenteral iron formulations—the oral ones—being inefficient. Various studies showed the safety and efficacy of parenteral iron formulations in correcting hemoglobin levels and decreasing the blood transfusion rate, the overall mortality, the postoperative infections incidence, hospitalization days, and the general costs.

Factors influencing safety and efficacy of intravenous iron-carbohydrate nanomedicines: From production to clinical practice

Iron deficiency is an important subclinical disease affecting over one billion people worldwide. A growing body of clinical records supports the use of intravenous iron-carbohydrate complexes for patients where iron replenishment is necessary and oral iron supplements are either ineffective or cannot be tolerated by the gastrointestinal tract. A critical characteristic of iron-carbohydrate drugs is the complexity of their core-shell structure, which has led to differences in the efficacy and safety of various iron formulations. This review describes parameters influencing the safety and effectiveness of iron-carbohydrate complexes during production, storage, handling, and clinical application. We summarized the physicochemical and biological assessments of commercially available iron carbohydrate nanomedicines to provide an overview of publicly available data. Further, we reviewed studies that described how subtle differences in the manufacturing process of iron-carbohydrate complexes can impact on the physicochemical, biological, and clinical outcomes of original product versus their intended copies or so-called iron "similar" products.

Iron Accumulates in Retinal Vascular Endothelial Cells But Has Minimal Retinal Penetration After IP Iron Dextran Injection in Mice

Purpose

Iron supplementation therapy is used for iron-deficiency anemia but has been associated with macular degeneration in a 43-year-old patient. Iron entry into the neurosensory retina (NSR) can be toxic. It is important to determine conditions under which serum iron might cross the blood retinal barrier (BRB) into the NSR. Herein, an established mouse model of systemic iron overload using high-dose intraperitoneal iron dextran (IP FeDex) was studied. In addition, because the NSR expresses the iron regulatory hormone hepcidin, which could limit iron influx into the NSR, we gave retina-specific hepcidin knockout (RS-HepcKO) mice IP FeDex to test this possibility.

Methods

Wild-type (WT) and RS-HepcKO mice were given IP FeDex. In vivo retina imaging was performed. Blood and tissues were analyzed for iron levels. Quantitative PCR was used to measure levels of mRNAs encoding iron regulatory and photoreceptor-specific genes. Ferritin and albumin were localized in the retina by immunofluorescence.

Results

IP FeDex in both WT and RS-HepcKO mice induced high levels of iron in the liver, serum, retinal vascular endothelial cells (rVECs), and RPE, but not the NSR. The BRB remained intact. Retinal degeneration did not occur.

Conclusions

Following injection of high-dose IP FeDex, iron accumulated in the BRB, but not the NSR. Thus, the BRB can shield the NSR from iron delivered in this manner. This ability is not dependent on NSR hepcidin production.

Snapshots of Iron Speciation: Tracking the Fate of Iron Nanoparticle Drugs via a Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Approach

Nanomedicines are nanoparticle-based therapeutic or diagnostic agents designed for targeted delivery or enhanced stability. Nanotechnology has been successfully employed to develop various drug formulations with improved pharmacokinetic characteristics, and current research efforts are focused on the development of new innovator and generic nanomedicines. Nanomedicines, which are often denoted as complex or nonbiological complex drugs, have inherently different physicochemical and pharmacokinetic properties than conventional small molecule drugs. The tools necessary to fully evaluate nanomedicines in clinical settings are limited, which can hamper their development. One of the most successful families of nanomedicines are iron-carbohydrate nanoparticles, which are administered intravenously (IV) to treat iron-deficiency anemia. In the U.S., the FDA has approved six distinct iron-carbohydrate nanoparticles but only one generic version (sodium ferric gluconate for Ferrlecit). There is significant interest in approving additional generic iron-carbohydrate drugs; however, the lack of a direct method to monitor the fate of the iron nanoparticles in clinical samples has impeded this approval. Herein we report a novel liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) method that allows for the direct quantification of the iron-carbohydrate drugs in clinical samples, while simultaneously measuring the speciation of the iron released from the nanoparticles in biological samples. To our knowledge, this is the first time that iron nanoparticles have been observed in clinical samples, opening the door for direct pharmacokinetic studies of this family of drugs. This method has potential applications not only for iron-nanoparticle drugs but also for any nanomedicine with an inorganic component.

Protective Role of Histidine Supplementation Against Oxidative Stress Damage in the Management of Anemia of Chronic Kidney Disease

Anemia is a major health condition associated with chronic kidney disease (CKD). A key underlying cause of this disorder is iron deficiency. Although intravenous iron treatment can be beneficial in correcting CKD-associated anemia, surplus iron can be detrimental and cause complications. Excessive generation of reactive oxygen species (ROS), particularly by mitochondria, leads to tissue oxidation and damage to DNA, proteins, and lipids. Oxidative stress increase in CKD has been further implicated in the pathogenesis of vascular calcification. Iron supplementation leads to the availability of excess free iron that is toxic and generates ROS that is linked, in turn, to inflammation, endothelial dysfunction, and cardiovascular disease. Histidine is indispensable to uremic patients because of the tendency toward negative plasma histidine levels. Histidine-deficient diets predispose healthy subjects to anemia and accentuate anemia in chronic uremic patients. Histidine is essential in globin synthesis and erythropoiesis and has also been implicated in the enhancement of iron absorption from human diets. Studies have found that L-histidine exhibits antioxidant capabilities, such as scavenging free radicals and chelating divalent metal ions, hence the advocacy for its use in improving oxidative stress in CKD. The current review advances and discusses evidence for iron-induced toxicity in CKD and the mechanisms by which histidine exerts cytoprotective functions.

Ferric pyrophosphate citrate: interactions with transferrin

There are several options available for intravenous application of iron supplements, but they all have a similar structure:—an iron core surrounded by a carbohydrate coating. These nanoparticles require processing by the reticuloendothelial system to release iron, which is subsequently picked up by the iron-binding protein transferrin and distributed throughout the body, with most of the iron supplied to the bone marrow. This process risks exposing cells and tissues to free iron, which is potentially toxic due to its high redox activity. A new parenteral iron formation, ferric pyrophosphate citrate (FPC), has a novel structure that differs from conventional intravenous iron formulations, consisting of an iron atom complexed to one pyrophosphate and two citrate anions. In this study, we show that FPC can directly transfer iron to apo-transferrin. Kinetic analyses reveal that FPC donates iron to apo-transferrin with fast binding kinetics. In addition, the crystal structure of transferrin bound to FPC shows that FPC can donate iron to both iron-binding sites found within the transferrin structure. Examination of the iron-binding sites demonstrates that the iron atoms in both sites are fully encapsulated, forming bonds with amino acid side chains in the protein as well as pyrophosphate and carbonate anions. Taken together, these data demonstrate that, unlike intravenous iron formulations, FPC can directly and rapidly donate iron to transferrin in a manner that does not expose cells and tissues to the damaging effects of free, redox-active iron.

Oral Ferric Citrate Hydrate Associated With Less Oxidative Stress Than Intravenous Saccharated Ferric Oxide

Introduction

A recent study suggested that orally dosed ferric citrate hydrate (FC) corrects renal anemia in patients on hemodialysis (HD), suggesting biological differences in effects of iron supplementation using different routes of administration. To address this issue, the present study compared oral FC with i.v. saccharated ferric oxide (FO) in stable HD patients.

Methods

Participants comprised 6 patients administered 3 consecutive protocols in the first HD session of the week in a fasting state: nothing given, as control (C); oral load of FC (480 mg iron), and 5 minutes of i.v. FO (40 mg iron). Iron dynamics in the body and biological impact on redox-inflammation status during the study (6 hours) were examined.

Results

Significant increases in serum iron and transferrin saturation were seen with both FC and FO. Regarding total iron-binding capacity as the sum of serum iron and unsaturated iron-binding capacity, no changes were found in FC, whereas significant increases were seen in FO (appearance of non–transferrin-binding iron [NTBI]), despite the lower serum iron levels in FO. Compared with C, increases were seen in serum myeloperoxidase (oxidative marker) with accompanying significant decreases in thioredoxin (antioxidant) in FO, whereas no changes were found in FC.

Conclusion

Oral FC differs from i.v. FO in areas such as less NTBI generation and less induction of oxidative stress. The result indicates potential clinical benefits of oral FC in terms of iron supplementation for renal anemia in HD patients.

Physicochemical Characterization of Iron Carbohydrate Colloid Drug Products

Iron carbohydrate colloid drug products are intravenously administered to patients with chronic kidney disease for the treatment of iron deficiency anemia. Physicochemical characterization of iron colloids is critical to establish pharmaceutical equivalence between an innovator iron colloid product and generic version. The purpose of this review is to summarize literature-reported techniques for physicochemical characterization of iron carbohydrate colloid drug products. The mechanisms, reported testing results, and common technical pitfalls for individual characterization test are discussed. A better understanding of the physicochemical characterization techniques will facilitate generic iron carbohydrate colloid product development, accelerate products to market, and ensure iron carbohydrate colloid product quality.