Screening of water distilled Rosa damascena Mill. flowers as hematopoietic agent in an animal model

Pancytopenia is classified as low blood cell count. Low levels of hemoglobin, red blood cells, white blood cells and platelets are indicative of pancytopenic state. This pancytopenic state can be treatment (drug) or disease induced. Conventional approaches available to treat pancytopenia are usually associated with many undesirable adverse effects, are costly and parenterally administered. Interest in natural products has significantly increased due to their ability to stimulate cellular components of immune system. This study is designed to investigate the hematopoietic i.e. erythropoeitic, leucopoietic and thrombopoeitic potential of water distilled flowers of Rosa damascena Mill.

Comparisons of antithrombosis, hematopoietic effects and chemical profiles of dried and rice wine-processed Rehmanniae Radix extracts

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine (TCM), Rehmanniae Radix (RR, derived from the root of Rehmannia glutinosa (Gaertn.) DC.) is commonly used as natural medicine for thousands of years, two types including the dried and rice-wine processed RR were used for different clinical purposes respectively, which were the typical case that pharmaceutical effect changed by processing in TCM.

AIM OF STUDY

The goal of this study was to investigate the differences in the antithrombosis and hematopoietic effects of extracts of dried and processed RR (DRR and PRR) in vivo, and to explore the chemical basis underlying changes of medicinal properties caused by processing.

MATERIALS AND METHODS

The aqueous extracts of DRR and PRR were prepared. Protective effect of varying doses of different extracts were investigated in type-I carrageenan induced mice tail thrombosis and cyclophosphamide induced myelosuppression model. The chemical composition of DRR and PRR extracts were determined by High Performance Liquid Chromatography coupled with tandem quadrupole time-of-flight Mass Spectrometry (HPLC/Q-TOF-MS).

RESULTS

In antithrombosis activity tests, PRR possessed less ameliorated effects than DRR in the model mouse on body temperature, tail thrombus length and blood flow. Both DRR and PRR had no significant influence on prothrombin time (PT) and activated partial thromboplastin time (APTT), only high dose DRR could decrease the content of fibrinogen (FIB) in plasma. Histological examination of lung tissue suggested that thrombosis was significantly improved in DRR-H group. For myelosuppression model, only PRR could improve peripheral hemogram, both DRR and PRR had hematopoietic effects as demonstrated by their abilities to ameliorate the bone marrow nucleated cells (BMNC) and pathology of bone marrow tissue. The hematopoietic effects of PRR were significantly more potent than that of DRR at the concentration of 9 g/kg. By comparing the chemical composition, we found that iridoid glycosides were decreased and furfural derivatives increased in DRR after processing which may be the chemical mechanism contribute to the differences in efficacy.

CONCLUSIONS

According to the results of this research, processing with rice wine for nine cycles significantly reduced antithrombotic effects and enhanced the hematopoietic effects of DRR as demonstrated in model mice. It can scientifically explain the different effect among two types of RR in clinical through the diverse method of processing and usage. Meanwhile, the predicted activity compounds from two types of RR can be potential candidates for the treatment of thrombosis and anemia.

Semi-mechanistic Pharmacokinetic/Pharmacodynamic model of three pegylated rHuEPO and ior®EPOCIM in New Zealand rabbits

Marketed formulations of erythropoietin (EPO) ior®EPOCIM, MIRCERA® and two newly developed pegylated-EPO analogues (PEG-EPO 32 and 40 kDa) formulations were intravenously administered to New Zealand rabbits. A semi-mechanistic Pharmacokinetic/Pharmacodynamic (PK/PD) model describing in a simultaneous and integrated form the time course of reticulocytes, red blood cells and hemoglobin was built to account for the time course of hematopoiesis stimulation after erythropoietin administration. Data analysis was performed based on the population approach with the software NONMEM version 7.3. Erythropoietin disposition of each of the administered formulations was best described with a two compartment model and linear elimination. Different formulations show different clearance and apparent volume of distribution of the central compartment but share estimates of inter-compartmental clearance and apparent peripheral volume of distribution. A semi-mechanistic model including cell proliferation, maturation, and homeostatic regulation provided a good description of the data regardless the type of erythropoietin formulation administered. The system-, and drug-related parameters showed consistency and differed across formulations, respectively. A single IV administration of PEG-EPO 32 and 40 kDa formulations in New Zealand rabbits achieves a median change of 27% and 22% on RET levels, and of 47% and 63% on RBC and HGB levels, respectively compared to MIRCERA®. The administration of new branched PEG-chains formulations improves PK and PD properties of EPO, in terms of increasing elimination half-lives and pharmacological activity on RET, RBC and HGB compared to commercially available formulations (ior®EPOCIM and MIRCERA®).

Particle Size, Surface Area, and Amorphous Content as Predictors of Solubility and Bioavailability for Five Commercial Sources of Ferric Orthophosphate in Ready-To-Eat Cereal

Ferric orthophosphate (FePO₄) has had limited use as an iron fortificant in ready-to-eat (RTE) cereal because of its variable bioavailability, the mechanism of which is poorly understood. Even though FePO₄ has desirable sensory properties as compared to other affordable iron fortificants, few published studies have well-characterized its physicochemical properties. Semi-crystalline materials such as FePO₄ have varying degrees of molecular disorder, referred to as amorphous content, which is hypothesized to be an important factor in bioavailability. The objective of this study was to systematically measure the physicochemical factors of particle size, surface area, amorphous content, and solubility underlying the variation in FePO₄ bioavailability. Five commercial FePO₄ sources and ferrous sulfate were added to individual batches of RTE cereal. The relative bioavailability value (RBV) of each iron source, determined using the AOAC Rat Hemoglobin Repletion Bioassay, ranged from 51% to 99% (p < 0.05), which is higher than typically reported. Solubility in dilute HCl accurately predicted RBV (R² = 0.93, p = 0.008). Amorphous content measured by Dynamic Vapor Sorption ranged from 1.7% to 23.8% and was a better determinant of solubility (R² = 0.91; p = 0.0002) than surface area (R² = 0.83; p = 0.002) and median particle size (R² = 0.59; p = 0.12). The results indicate that while solubility of FePO₄ is highly predictive of RBV, solubility, in turn, is strongly linked to amorphous content and surface area. This information may prove useful for the production of FePO₄ with the desired RBV.

Capillary Electrophoresis Method for the Assessment of Erythropoiesis-Stimulating Agents in Final Formulations

Capillary electrophoresis (CE) comprises several separation modes that can be used to characterize proteins in terms of physico-chemical properties such as isoelectric point or molecular weight, or in terms of purity/heterogeneity for the presence of charge or size variants. In glycoproteins the heterogeneity occurring as a consequence of variable amounts of terminal sialic acid residues on glycan moieties can be detected by CE. As such, a capillary zone electrophoresis (CZE) method was found suitable for the detection of isoforms of several erythropoiesis-stimulating agents (Bietlot and Girard, J Chromatogr A 759:177-184, 1997; Boucher et al., J Pharm Biomed Anal 71:207-213, 2012). In particular, the method can be used to analyze finished products containing erythropoietin-α, erythropoietin-β, or darbepoetin-α regardless of the formulation and without the need for sample pretreatment. The major excipients encountered in the various formulations included polysorbate 80, polysorbate 20, or human serum albumin. The ability of the method to resolve isoforms of the active ingredient in finished product enables the comparison of the isoform profile with that of the corresponding drug substance, allowing the assessment of the structural integrity and content of the active ingredients in finished products.

Ferric sulphate alterations on primary dentin and the adhesive interface

PURPOSE

The purpose of this study was to test the hypothesis that the pulp medication ferric sulphate (FS) may remain on primary dentin, affecting its microchemical structure and the bond strength of adhesives to primary dentin.

MATERIALS AND METHODS

The effects of FS and pre-bonding conditioning (37% phosphoric acid [PA] for 15 s or a self-etching primer, with or without the use of 2% chlorhexidine [CHX]) on FS-treated primary dentin were characterized using optical microscopy with Masson's and Perls' stains, variable-pressure SEM/energy-dispersive x-ray spectroscopy (VP-SEM/EDS), Fourier transform infrared spectroscopy (FT-IR), and x-ray diffraction. Ferric sulphate was applied for 30 s or 1 h for microchemical analysis. The adhesive interface and the bond strength were studied by VP-SEM/EDS and the μTBS test (1 mm2 bars, crosshead speed 0.5 mm/min), respectively. The study groups were: etch-and-rinse (E&R, Excite) adhesive (group 1); FS+E&R (group 2); FS+CHX+E&R (group 3); self-etching (SE, Adper Scotchbond) adhesive (group 4); FS+SE (group 5); FS+CHX+SE (group 6).

RESULTS

Ferric sulphate application produced demineralization, gypsum formation, and adsorption of Fe on the dentin surface, and it modified the collagen structure of primary dentin. There were no effects of FS on bond strength of the tested etch-and-rinse adhesive system. FS slightly reduced the bond strength between the primary dentin and the SE adhesive, and the values were not restored by CHX (group 4 = 17.58 ± 5.52 MPa > group 5 = 14.26 ± 7.08 MPa = group 6 = 13.96 ± 4.87 MPa).

CONCLUSIONS

Ferric sulphate alters the microchemical structure of primary dentin and can impair the adhesive strength of some self-etching adhesives.

Powerful inner/outer controlled multi-target magnetic nanoparticle drug carrier prepared by liquid photo-immobilization

Nanomagnetic materials offer exciting avenues for advancing cancer therapies. Most researches have focused on efficient delivery of drugs in the body by incorporating various drug molecules onto the surface of nanomagnetic particles. The challenge is how to synthesize low toxic nanocarriers with multi-target drug loading. The cancer cell death mechanisms associated with those nanocarriers remain unclear either. Following the cell biology mechanisms, we develop a liquid photo-immobilization approach to attach doxorubicin, folic acid, tumor necrosis factor-α, and interferon-γ onto the oleic acid molecules coated Fe3O4 magnetic nanoparticles to prepare a kind of novel inner/outer controlled multi-target magnetic nanoparticle drug carrier. In this work, this approach is demonstrated by a variety of structural and biomedical characterizations, addressing the anti-cancer effects in vivo and in vitro on the HeLa, and it is highly efficient and powerful in treating cancer cells in a valuable programmed cell death mechanism for overcoming drug resistance.

Erythropoietic agents from natural sources

Anemia occurs frequently in individuals who suffer from chronic kidney disease (CKD) or gynecologic disease or who receive anticancer therapy. Since 1988, medical practitioners have treated patients with anemia successfully with recombinant human erythropoietin (EPO), which is currently the largest therapeutic protein class in the world. It has some disadvantages, however, such as high cost, parenteral administration, and immunogenicity. A novel, economical, orally administrable, and nonimmunogenic hematopoietic agent would be valuable as an alternative or supportive therapy for EPO. Considering the long history of usage of natural products and the recent progress in identification of their active constituents, especially of herbal medicines, researchers and clinicians should find natural products to be useful sources of hematopoietic drugs. In this review, the authors have described EPO therapy and traditional medicines for anemia, including their mechanisms of action for erythropoiesis.

Comparison of adverse event profile of intravenous iron sucrose and iron sucrose similar in postpartum and gynecologic operative patients

OBJECTIVE

Severe iron deficiency resulting in anemia is a common problem during pregnancy and in menstruating women. Several choices for IV iron replacement therapies exist and increased pressures on budgets may require cheaper 'iron sucrose similar' (ISS) to be used. In our practice, an iron sucrose similar (Ferex; ISS(FRX)) was introduced to reduce costs in the treatment of pregnant women or those planned for surgery. Post several months of use we observed increased rates of adverse events from patients and hence performed this analysis to confirm these findings.

METHODS

Data on adverse events was retrospectively collected from 658 patients treated between September 2004 and December 2011. Patients were analyzed in three cohorts, iron sucrose originator (IS(ORIG)), ISS(FRX) diluted in 100 mL saline and ISS(FRX) diluted in 200 mL saline.

RESULTS

The mean age was 38.5 years and included patients having normal delivery, Cesarean section, myomectomy, hysterectomy, cystectomy and adnexectomy. There were 169 patients in the IS(ORG) group and 210 and 279 in the ISS(FRX)-100 and ISS(FRX)-200 groups respectively. Adverse drug reactions were more frequent in the ISS(FRX) groups vs. IS(ORIG) (11.0 vs. 14.3 vs. 1.8%; p < 0.02). Events were mild-to-moderate in nature and were predominately injection site reactions and phlebitis.

RESULTS

may be impacted by imbalance in baseline characteristics and cumulative iron dose received, however events were mostly acute and all patients received 200 mg iron as single administration.

CONCLUSION

This is the first large analysis suggesting increased adverse events due to an ISS. For our practice, the use of ISS(FRX) was discontinued owing to safety concerns outweighing the theoretical cost benefit. This study raises the question on the appropriate approval process for complex drugs and if these can be substituted without appropriate clinical testing, both for efficacy and most importantly safety, in routine clinical practice.

Short-term stability of a new generic sodium ferric gluconate in complex with sucrose

BACKGROUND

Sodium ferric gluconate in complex (SFG) is used to treat iron deficiency anemia in patients aged ≥6 years undergoing chronic hemodialysis and receiving supplemental epoetin therapy. Both the branded product (Ferrlecit, branded SFG) and a new generic version of sodium ferric gluconate in complex (Nulecit; generic SFG) are provided in 5 mL vials. SFG may be administered by slow intravenous (IV) injection of the undiluted product or by 1 h IV infusion after dilution in 100 mL 0.9% sodium chloride. This study evaluated the short-term stability of undiluted and diluted generic SFG at room temperature and under refrigeration.

METHODS

Samples of generic SFG undiluted in 10 mL syringes or diluted in IV infusion bags containing 0.9% sodium chloride solution were stored at room temperature or under refrigerated conditions (2-8°C). Samples at room temperature were stored for ≤48 h if undiluted and for ≤24 h if diluted. All refrigerated samples were stored for ≤7 days. Parameters evaluated were elemental iron (Fe) concentration and SFG apparent molecular weight. All tests were performed on two lots of the generic product.

RESULTS

Fe concentrations were identical in both lots and did not vary substantially over time under different conditions of storage or dilution. SFG apparent molecular weight varied across all samples from 306,000 to 354,000 Daltons, well within the range of 289,000 to 440,000 Daltons specified as the molecular weight in the FDA-approved prescribing information.

CONCLUSION

Iron content and SFG apparent molecular weight were stable under all experimental conditions. Undiluted generic SFG was stable for ≥2 days at room temperature and ≥7 days under refrigerated conditions, and generic SFG diluted in IV infusion bags containing 0.9% sodium chloride solution was stable for ≥1 day at room temperature and ≥7 days under refrigerated conditions.

An alternative to animal testing in the quality control of erythropoietin

A physico-chemical method has been developed as an alternative to the current bioassay in normocythaemic mice for estimating the biological activity of erythropoietin batches. Capillary zone electrophoresis was used for quantification of the isoforms and their substructures were further elucidated by N-glycan mapping techniques. The analytical study was carried out on a total of 40 batches of epoetin beta which were selected to cover an adequate range of precisely established potency values. The relationship between the biological and chemical parameters was evaluated statistically in order to identify suitable covariates for the prediction of the biological activity. Out of several alternatives, a prediction model which is based on the percentages of isoforms per batch and the degree of sialidation was selected and tested. This model is comparable in terms of accuracy to the established in vivo bioassay, but is far superior in terms of precision. Further advantages of the method are improved animal welfare and savings in time and effort. The question whether the prediction model already meets the requirements for replacing the bioassay according to the ICH guideline Q6B is discussed.

A magnetofluorescent nanoparticle for ex-vivo cell labeling by covalently linking the drugs protamine and Feraheme

We synthesized a nanoparticle (NP) for ex-vivo cell labeling and MRI tracking by covalently coupling the C-terminus of a rhodamine-labeled protamine (ProRho) to Feraheme (FH) in order to yield the nanoparticle denoted ProRho-FH. Since protamine can adsorb to certain charged surfaces, we confirmed a covalent interaction between ProRho and FH by heparin affinity chromatography. ProRho-FH lacks a net charge (zeta potential approximately 0) due to the combination of negative FH and positive ProRho charges. ProRho-FH was readily internalized by U87 cells and mouse mesenchymal stem cells as determined by FACS and MR relaxometry. Finally, some 4,000 stem cells were implanted in a mouse brain and imaged by MRI. Due to its lack of net surface charge, ProRho-FH relies on the internalizing properties of the surface guanidinium groups present in the arginine-rich protamine to induce NP uptake. ProRho-FH is a unique cell-labeling agent due to its synthesis using two approved drugs, magnetofluorescence, site-specific covalent attachment chemistry, and lack of surface charge.

High-frequency, magnetic-field-responsive drug release from magnetic nanoparticle/organic hybrid based on hyperthermic effect

Magnetic nanoparticles (MNPs) generate heat when a high-frequency magnetic field (HFMF) is applied to them. Induction heat is useful not only for hyperthermia treatment but also as a driving force for drug-release. beta-Cyclodextrin (CD) can act as drug container because of its inclusion properties. Drugs incorporated in the CD can thus be released through the use of induction heating, or hyperthermic effects, by applying a HFMF. In this study, we have synthesized folic acid (FA) and CD-functionalized superparamagnetic iron oxide nanoparticles, FA-CD-SPIONs, by chemically modifying SPIONs derived from iron(III) allylacetylacetonate. FA is well-known as a targeting ligand for breast cancer tumor and endows the SPIONs with cancer-targeting capability. Immobilization of FA and CD on spinel iron oxide nanoparticles was confirmed by Fourier transform IR (FTIR) and X-ray photoelectron spectroscopy (XPS). The FA-CD-SPIONs have a hydrodynamic diameter of 12.4 nm and prolonged stability in water. They are superparamagnetic with a magnetization of 51 emu g(-1) at 16 kOe. They generate heat when an alternating current (AC) magnetic field is applied to them and have a specific absorption rate (SAR) of 132 W g(-1) at 230 kHz and 100 Oe. Induction heating triggers drug release from the CD cavity on the particle - a behavior that is controlled by switching the HFMF on and off. The FA-CD-SPIONs are noncytotoxic for cells. Thus, FA-CD-SPIONs can serve as a novel device for performing drug delivery and hyperthermia simultaneously.

Iron replacement therapy: assessing today's options to prepare for bundling

New Medicare rules that set forth a revised reimbursement scheme for dialysis services will introduce significant changes for providers. The new rules will abandon the current system of separate reimbursement for drugs associated with the hemodialysis services, including erythropoiesis-stimulating agents (ESAs) and intravenous (i.v.) iron. These rules will "bundle" these agents and related laboratory tests into a single, case-mix adjusted composite rate. These bundling rules will be gradually phased-in, beginning in 2011. One of the primary effects of the new reimbursement policy will be to discourage over-utilization of ESAs that comprise nearly one-quarter of hemodialysis-related Medicare expenditures. As a result, hemodialysis providers will be challenged to make hemodialysis services more cost-effective, while ensuring that Medicare clinical performance measures are met and patient care is not compromised. i.v. iron has an integral role in making anemia care more cost-effective in the hemodialysis setting by improving measures of iron-deficiency anemia, maintaining necessary iron balance, and reducing the utilization of ESAs. This review discusses the potential benefits of i.v. iron in the management of hemodialysis patients with iron-deficiency anemia. It also focuses on the available i.v. iron options, particularly the established efficacy and safety profile of i.v. iron dextran compared with other i.v. iron formulations as well as cost considerations.

The oxidation of methionine-54 of epoetinum alfa does not affect molecular structure or stability, but does decrease biological activity

Erythropoietin therapy is used to treat severe anemia in renal failure and chemotherapy patients. One of these therapies based on recombinant human erythropoietin is marketed under the trade name of EPREX and utilizes epoetinum alfa as the active pharmaceutical ingredient. The effect of oxidation of methionine-54 on the structure and stability of the erythropoietin molecule has not been directly tested. We have observed partial and full chemical oxidation of methionine-54 to methionine-54 sulfoxide, accomplished using tert-Butylhydroperoxide and hydrogen peroxide, respectively. A blue shift in the fluorescence center of spectral mass wavelength was observed as a linear response to the level of methionine sulfoxide in the epoetinum alfa molecule, presumably arising from a local change in the environment near tryptophan-51, as supported by potassium iodide quenching studies. Circular dichroism studies demonstrated no change in the folded structure of the molecule with methionine oxidation. The thermal unfolding profiles of partial and completely oxidized epoetinum alfa overlap, with a T(m) of 49.5 degrees C across all levels of methionine sulfoxide content. When the protein was tested for activity, a decrease in biological activity was observed, correlating with methionine sulfoxide levels. An allosteric effect between Met54, Trp51, and residues involved in receptor binding is proposed. These results indicate that methionine oxidation has no effect on the folded structure and global thermodynamic stability of the recombinant human erythropoietin molecule. Oxidation can affect potency, but only at levels significantly in excess of those seen in EPREX.

Protein isolated from biopharmaceutical formulations cannot be used for comparative studies: Follow-up to "a case study using Epoetin Alfa from Epogen and EPREX"

In the biotechnology area, the issue of comparability with an innovator product is complex. Ideally, a side-by-side comparison of physical properties would be part of the demonstration of comparability. However, biogeneric companies do not have access to the bulk drug substance from the innovator company for biophysical comparison, and isolation of protein from marketed product cannot be guaranteed to produce material that is identical to the bulk drug substance from which it was prepared. In a recently published study, protein was isolated from marketed product and comparative studies performed. In a follow-up investigation of the published work, we demonstrate here that even a simple isolation procedure can significantly compromise the protein, which raises serious questions about the interpretation of that study, and in a broader context the value of any studies done with such "out-of-process" protein.

Lack of an Effect of Oral Iron Administration on Mycophenolic Acid Pharmacokinetics in Stable Renal Transplant Recipients

STUDY OBJECTIVES

To determine if coadministration of polysaccharide iron complex and slow-release ferrous sulfate alter the absorption of mycophenolic acid (MPA), and to examine the potential influence of dosing relative to mycophenolate mofetil (MMF) administration and the effect of immediate- versus sustained-release iron products on the steady-state pharmacokinetics of MPA.

DESIGN

Prospective, open-label, three-phase, crossover, steady-state pharmacokinetic study.

SETTING

National Institutes of Health-sponsored General Clinical Research Center at a university medical center.

PATIENTS

Twelve adult (mean age 50 yrs) renal transplant recipients who were receiving concomitant iron and MMF maintenance therapy.

INTERVENTION

Oral iron therapy was coadministered with MMF on days -6-0, MMF was administered alone on days 1-8 (control phase), then oral iron therapy was administered 2 hours after MMF administration on days 9-16.

MEASUREMENTS AND MAIN RESULTS

Baseline demographics, concurrent drug regimens, and clinical laboratory values were assessed. Blood samples were obtained at baseline and at 1, 2, 3, 4, 6, 8, and 12 hours after MMF administration on days 0, 8, and 16. The MPA levels were measured by high-performance liquid chromatography. We found no significant differences in the dose-standardized area under the concentration-time curve from 0-12 hours (AUC(0-12)) for MPA between the control phase (39.66 +/- 8.70 mg mg x hr/L) and the concomitant ferrous sulfate or dose-separated ferrous sulfate (37.56 +/- 9.95 or 32.84 +/- 8.43 mg x hr/L, respectively, p>0.05) phases. Dose-standardized AUC(0-12) values for MPA did not significantly differ after the concomitant administration of polysaccharide iron complex from that of the control phase (48.46 +/- 9.68 and 43.80 +/- 9.46 mg x hr/L, respectively, p=0.065). However, the AUC(0-12) for MPA significantly increased when polysaccharide iron complex was administered 2 hours after MMF (53.41 +/- 11.75 mg x hr/L, p=0.012). Maximum concentrations and times to reach maximum concentrations remained consistent across all study phases in each arm of the trial (p>0.05).

CONCLUSION

Multiple doses of iron therapy-slow-release ferrous sulfate, or polysaccharide iron complex-did not significantly reduce systemic exposure to MMF, as measured by using AUC(0-12) values.

Development of spherical iron(II) sulfate heptahydrate-containing solid particles with sustained drug release

The aim of this work was to develop a simple, economic procedure for the manufacturing of coated iron(II) sulfate particles by using a crystallization technique for the development of round particles, followed by coating with a lipophilic material. Several batches of iron(II) sulfate heptahydrate were produced by a cooling crystallization, with variation of the crystallization parameters. The spherical crystals were coated with stearin. The products were characterized for particle size, roundness, bulk density and in vitro drug dissolution. Crystallization was performed from deionized water with no addition of seed crystals and by cooling by applying a linear cooling rate. The developed iron(II) sulfate crystals were round with average diameter of 729+/-165 microm. The best form for the sustained release of iron(II) sulfate was the sample HTP-2 which contained 11% of stearin relative to the iron(II) sulfate. The spherical crystallization of iron(II) sulfate is simple and fast, and does not require a dangerous, expensive solvent. The round particles can coat directly with lipophilic material which results in slow release of iron(II) sulfate and protects the iron(II) from oxidation and inhibits the loss of crystal water. The coated crystals can be filled into capsules to yield the final dosage form.

Effect of fiber length of carbon nanotubes on the absorption of erythropoietin from rat small intestine

Erythropoietin (EPO) loaded carbon nanotubes (CNTs) with surfactant as an absorption enhancer were prepared for the oral delivery of EPO using two types of CNTs, long and short fiber length CNTs, and the effect of CNT fiber length on the absorption efficiency of EPO was studied. After Labrasol, PEG-8 caprylic/capric glycerides, as absorption enhancer was adsorbed into long fiber CNTs of which mean fiber length was 20-80 microm, as a carrier, EPO and casein as protease inhibitor and Explotab (sodium starch glycolate) as a disintegrating agent, were mixed. The resulting solid preparation was administered into the rat jejunum and serum EPO levels were measured by ELISA. The dose of EPO, CNTs, casein and Explotab were 100 IU/kg, 5mg/kg, 25mg/kg and 2.5mg/kg, respectively. Serum EPO level reached to C(max), 69.0+/-3.9 mIU/ml, at 3.5+/-0.1h and AUC was 175.7+/-13.8 mIU h/ml. These values were approximately half of that obtained with short fiber length CNTs of which C(max) was 143.1+/-15.2 mIU/ml and AUC was 256.3+/-9.7 mIU h/ml. When amphoteric surfactant, Lipomin LA, sodium beta-alkylaminopropionic acid, was used to accelerate the disaggregation of long fiber length CNTs, C(max) was 36.0+/-4.9 and AUC was 96.9+/-11.9, which showed less bioavailability (BA) of EPO. These results suggest that the short fiber length CNTs deliver more both EPO and absorption enhancer to the absorptive cells of the rat small intestine and the aggregation of CNTs is not the critical factor for the oral delivery of EPO.

Reaction to the paper: Interaction of Polysorbate 80 with Erythropoietin: A Case Study in Protein–Surfactant Interactions

Micelle-associated epoetin is still a possible explanation for the upsurge of pure red blood cell aplasia associated with subcutaneous use of epoetin alpha in patients with chronic renal failure.

Magnetic and structural study of the state of iron in the oral haematinic ferrimannitol ovoalbumin

From magnetic and structural analyses performed on ferrimannitol ovalbumin, iron in this drug is observed to be present as two-line ferrihydrite nanoparticles, of around 4 nm in diameter, which are superparamagnetic above approximately 20 K. Among other parameters, the temperature dependence of the magnetic out-of-phase susceptibility of this compound has been fully characterised and yields results clearly different from that of ferritin. This characterisation, performed for the first time for an oral haematinic, is of interest in the context of future pharmacological studies of this compound.

Extent of iron pick-up in deforoxamine-coupled polyurethane materials for therapy of chronic wounds

Polyurethane net substrates (PNS) coupled with deferoxamine (DFO) have been studied to determine the extent of Fe2+ pick-up for use in chronic wound therapy. A m solution of ferrous sulphate (FeSO4) was used to generate ferrous ions similar to those found in chronic wounds. The concentration of Fe as a function of position through the dressings was evaluated using a variety of techniques. Atomic force microscopy (AFM) and energy-filtered transmission electron microscopy (EFTEM) revealed a rough precipitated layer at the surface of activated PNS exposed to FeSO4 solution. Optical microscopy (OM) and backscattered environmental scanning electron microscopy (ESEM) showed a clear layer of Fe(3+)-enriched material in the surface regions exposed to DFO. The penetration depth of DFO into activated dressings was found to be 20-30 microm. Energy-dispersive X-ray (EDX) analysis was used to approximate the distribution of bound- and unbound-Fe as a function of position within BPNS and DFO-activated dressings after immersing them in a FeSO4 solution for various times. These studies have shown the activity of iron with respect to ionic state in DFO-activated PNS for potential using as dressing for chronic wounds.

A comparison of the bioequivalence of two formulations of epoetin alfa after subcutaneous injection

BACKGROUND

The previous formulation of epoetin alfa in Japan was a citrate-buffered protein solution containing gelatin hydrolysate as the protein protective agent. To eliminate pain at injection sites, and the risks of anaphylactic shock and unknown infections by gelatin we have developed a new formulation of phosphate-buffered epoetin alfa, which does not contain gelatin hydrolysate.

AIM

To compare the bioequivalence of two formulations of epoetin alfa administered by the subcutaneous route.

METHODS

Four separate studies were performed to assess the bioequivalence of two epoetin alfa formulations using different strength and doses, i.e. 750 IU per 0.5 ml x 0.5 ml (= 750 IU per subject), 750 IU per 0.5 ml x 4 ml (= 6000 IU per subject), 6000 IU per 0.5 ml x 0.5 ml (= 6000 IU per subject) and 24,000 IU per 0.5 ml x 0.125 ml (= 6000 IU per subject). Each study was a single-centre, open-label, randomized, two-treatment, two-period, crossover study for which healthy volunteers were enrolled. Bioequivalence was assessed using the confidence interval (CI) of the ratios for the log-transformed, baseline-corrected Cmax and AUC(0,t). Baseline-corrected AUC(0,t) was calculated using the following equation: AUC(0,t) = AUC(0,t), uncorrected -- predose level x observation period.

RESULTS

The ratios (gelatin-free/gelatin-containing) for the log-transformed Cmax and AUC(0,t) after 6000 IU per subject injection of three different concentrations of epoetin alfa were well within the usual range for bioequivalence (90% CI 0.8, 1.25). The 90% CI of the ratio for Cmax after 750 IU per subject injection was 0.906, 1.24, which was within the bioequivalence range. However, the ratio for AUC(0,t) was not determined in this lowest dose because of negative AUC(0,t) values obtained in 12/60 cases. The overall safety data were consistent with those expected for a healthy study population, and did not present any concerns suggestive of adverse effects due to either formulation.

CONCLUSIONS

The point estimates and 90% CIs of the ratios of Cmax and AUC(0,t) for the gelatin-free/gelatin-containing formulations indicated that the two formulations are bioequivalent.

Micelle-Associated Protein in Epoetin Formulations: A Risk Factor for Immunogenicity?

PURPOSE

An upsurge of pure red cell aplasia (PRCA) cases associated with subcutaneous treatment with epoetin alpha has been reported. A formulation change introduced in 1998 is suspected to be the reason for the induction of antibodies that also neutralize the native protein. The aim of this study was to detect the mechanism by which the new formulation may induce these antibodies.

METHODS

Formulations of epoetin were subjected to gel permeation chromatography with UV detection, and the fractions were analyzed by an immunoassay for the presence of epoetin.

RESULTS

The chromatograms showed that Eprex/Erypo contained micelles of Tween 80. A minute amount of epoetin (0.008-0.033% of the total epoetin content) coeluted with the micelles, as evidenced by ELISA. When 0.03% (w/v) Tween 80, corresponding to the concentration in the formulation, was added to the elution medium, the percentage of epoetin eluting before the main peak was 0.68%.

CONCLUSIONS

Eprex/Erypo contains micelle-associated epoetin, which may be a risk factor for the development of antibodies against epoetin.

Recombinant erythropoietin in clinical practice

The introduction of recombinant human erythropoietin (RHuEPO) has revolutionised the treatment of patients with anaemia of chronic renal disease. Clinical studies have demonstrated that RHuEPO is also useful in various non-uraemic conditions including haematological and oncological disorders, prematurity, HIV infection, and perioperative therapies. Besides highlighting both the historical and functional aspects of RHuEPO, this review discusses the applications of RHuEPO in clinical practice and the potential problems of RHuEPO treatment.

Stability of multidose, preserved formulation epoetin alfa in syringes for three and six weeks

The integrity and biological activity of multidose, preserved formulation epoetin alfa stored in syringes at 2-8 degrees C were studied. Three independent 1.0-mL hubless syringes of epoetin alfa 20,000 units/mL were aseptically prepared and refrigerated for three and six weeks (a total of six syringes). Protein integrity was assayed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting, and glycoprotein detection. Biological activity was determined through a cell-based proliferation assay. The presence or absence of microbial contamination was observed after a one-week culture. A multidose, preserved formulation of epoetin alfa that was opened only at the time of assay served as the reference standard. SDS-PAGE silver-stained gels and immunoblots demonstrated no evidence of erythropoietin degradation after three and six weeks of storage when compared with the reference standard. In addition, SDS-PAGE, immunoblotting, and direct glycoprotein detection found that protein glycosylation was unaffected by the storage. Student's t test detected no significant difference between stored samples and the reference standard in biological activity (p > 0.05). A culture of epoetin alfa in bacterial and eukaryotic cell growth media showed no evidence of contamination. The results suggest that epoetin alfa can be dispensed to patients in prefilled syringes every four to six weeks to coincide with their peritoneal dialysis schedule. The integrity and biological activity of 20,000 units/mL epoetin alfa in prefilled syringes remain intact after three and six weeks when stored at 2-8 degrees C.

Folate-mediated drug delivery: effect of alternative conjugation chemistry

When utilized as a macromolecular drug targeting ligand, folic acid (Pte-Glu) has traditionally been coupled to peptides, proteins and lipids via one of its two carboxylate groups fortuitously located within a distal glutamyl moiety. It has been assumed in the literature that the gamma-glutamyl carboxylate of Pte-Glu is the preferred conjugation site for macromolecules enduring endocytosis via the folate-binding protein receptor. However, it is also possible that the steric placement of the attached macromolecule around the vitamin's pteridine moiety may be the more influential parameter controlling this delivery mechanism. Using solid-phase chemistries, we have synthesized dipeptide derivatives of pteroic acid for the purpose of identifying the preferred site onto which a macromolecule can be chemically attached without compromising its endocytosis potential. Thus, using fluorescent and radiolabeled conjugates, we have determined that macromolecules attached to Pte-Glu by either an alpha- or gamma-glutamyl linkage could associate with receptor-bearing cells at virtually identical levels. We further discovered that removal of the remaining un-conjugated glutamyl carboxylate had no inhibitory effect on cell uptake; and, the cytotoxicity of related momordin toxin conjugates were comparable among the various pteroate derivatives tested. From these observations we suggest that the preparation of endocytosis-competent pteroate-macromolecule conjugates is strongly influenced by the steric environment around the ligand's para-aminobenzoic acid moiety, and that no selective isomeric (i.e. alphaGlu versus gammaGlu) conjugation requirement necessarily exists.

In situ X-ray absorption spectroelectrochemical study of hydroxocobalamin

An in situ X-ray absorption spectroscopy (XAS) spectroelectrochemical study of aquocobalamin (system B12a-B12r-B12s) has been carried out in aqueous solutions buffered at different pH values. To the best of our knowledge, this is the first structural study of aquocobalamin at room temperature under controlled oxidation conditions. Most of the previous work was in fact performed using frozen samples chemically treated to produce the species. The spectroelectrochemical approach offers several advantages: (1) the reduction products may be studied without poisoning the system with chemical reductive reagents and (2) any possible variation of the oxidation state owing to the electrons produced by the incident beam is avoided as the electrode, under potentiostatic control, acts as a scavenger. The spectroelectrochemical approach, together with more careful data analysis, has led to an improved interpretation of the XAS data. These conditions were not met in previous works where the oxidation state was not controlled and multiple scattering contributions were not taken into account. The general shape of the XAS spectra of the different species is not greatly affected by pH. A signature for the base-off square-planar coordination has been evidenced for the Co(II) compound at basic pH. A new signature for Co(I), indicating square-planar coordination, has been identified on the experimental spectra and simulated in theoretical X-ray absorption near-edge structure (XANES) studies. The flexibility of the electrochemical approach, that permits to unambiguously establish the formal oxidation state, has led to very reliable values for energy shift and peak intensity variations. The experimental XANES and extended X-ray absorption fine structure (EXAFS) spectra with a very good signal-to-noise ratio have been processed using the GNXAS package that takes into account multiple scattering contributions. EXAFS and XANES independent analysis result in the same structural model. The reduction from Co(III) to Co(II) produces the most significant structural changes: the cobalt coordination number decreases from six to five, and the edge position shifts by 2.4 +/- 0.3 eV. In addition, the XANES spectra are strongly modified. The reduction from Co(II) to Co(I) produces mainly electronic effects with no apparent change of the coordination number. A discussion of the limits and potentialities of EXAFS in this type of study has also been included.

[Stability of 5-fluorouracil-folinic acid mixture: influence of concentrations, container and form of folinic acid]

Since the discovery of the superiority of the combination 5-fluorouracil (5FU)-folinic acid (FA) in comparison to 5FU alone in the treatment of gastrointestinal cancers, the interest of this association has been demonstrated in many other tumors. In the treatment of advanced colorectal carcinoma, FA is usually administered in 1 or 2 h infusion before 5FU. In treatment of other cancers, the two drugs are generally mixed together in the same container and administered as a continuous intravenous infusion over several days. Many studies have demonstrated the stability of 5FU alone in different vials, but results about compatibility of 5FU with AF in racemate (d,l) or levogyre (l) forms are conflicting. The aim of our study was to determine the influence of the container, the concentrations of the two drugs and the form of folinic acid (d, l or l) on the stability of the 5 FU-FA admixtures. Based on drug concentrations corresponding to current 5FU-FA chemotherapeutic protocols, 5FU was used at 50 mg/ml and 6.5 mg/ml in association with equitherapeutic and equimolar doses of FA respectively. Each association has been studied in three types of containers. For all combinations with 5FU 50 mg/ml, flocculation was noted, whatever form or concentration of FA which associated. No influence of the type of containers was noted. No precipitate was observed with the combinations 5FU 6.5 mg/ml. The evolution of the concentrations of 5FU and FA with time have been compared with a regression straight corresponding to a loss of product of 10% in 96 h. The mixtures 5FU 6.5 mg/ml with FA (d,l) 4 mg/ml and FA (l) 2 and 4 mg/ml remained stable in the three types of container. When a precipitate was noted (with 5FU 50 mg/ml), the concentration of 5FU decreased with time, whereas FA was stable in racemate and levogyre forms. Analysis of the precipitate showed that principally 5FU and equal parts of FA and calcium constituted it. Our results allowed to conclude that 5FU mixed with FA (d,l or l) 2 mg/ml and 4 mg/ml remained stable during 96 h in glass vials, PVC infusion bags and cassettes for portable pump in normal conditions of temperature and light. A precipitate of 5FU appears systematically with the concentration 50 mg/ml. These findings do not confirm those obtained in previously published studies. It seems that the precipitation is more a result of the decline of 5FU solubility at high concentrations than the form of folinic acid associated.

A Mössbauer and X-ray powder diffraction study of some ferrous hematinics

Iron deficiency anemia is a relatively common illness that can arise from a number of different causes. Three ferrous salts are usually used in its treatment: ferrous fumarate, gluconate, and sulfate. They are administered orally and are relatively well tolerated. These hematinics have been studied by Mössbauer spectroscopy and X-ray powder diffraction, and can easily be distinguished by both techniques. It was found that the two ferrous sulfates studied (Eckerd and SmithKline Beckman Co.) most closely resemble the monohydrate by comparison of the X-ray powder pattern with those of the JCPDS. Both the ferrous fumarate (Femiron) and gluconate (Spring Valley) had approximately 10% ferric iron present. To the authors' knowledge, this is the first reported Mössbauer spectrum for ferrous fumarate.

Comparison of polysaccharide iron complexes used as iron supplements

An oral hematinic marketed as "water soluble polysaccharide iron complex" (Vitaline Formulas) has been characterized using x-ray powder diffraction and Mössbauer spectroscopy. Another polysaccharide iron complex marketed as Niferex (Central Pharmaceuticals) has been previously studied by us and found to have a core similar to ferrihydrite, but with some long-range order of the mineral akaganéite, beta-FeOOH. The latter is seen in other ferric carbohydrate complexes synthesized by the hydrolysis of FeCl3. This commercial product, however, is very different and has a mixture of iron components including hematite (alpha-Fe2O3) magnetite (Fe3O4), goethite (alpha-FeOOH), iron metal, and a ferrous salt.