Carrageenan: Drug Delivery Systems and Other Biomedical Applications.

Marine resources are today a renewable source of various compounds, such as polysaccharides, that are used in the pharmaceutical, medical, cosmetic, and food fields. In recent years, considerable attention has been focused on carrageenan-based biomaterials due to their multifunctional qualities, including biodegradability, biocompatibility, and non-toxicity, in addition to bioactive attributes, such as their antiviral, antibacterial, antihyperlipidemic, anticoagulant, antioxidant, antitumor, and immunomodulating properties. They have been applied in pharmaceutical formulations as both their bioactive and physicochemical properties make them suitable biomaterials for drug delivery, and recently for the development of tissue engineering. This article provides a review of recent research on the various types of carrageenan-based biomedical and pharmaceutical applications.

Evaluation of Structural, Biological, and Functional Similarity of Biosimilar Granulocyte Colony Stimulating Factor to its Reference Product.

PURPOSE: Granulocyte colony stimulating factor (GCSF; also known as filgrastim) is a growth factor used to induce production of granulocytes. As the first locally developed and approved biosimilar medicine of Turkey, Fraven® being a biosimilar of filgrastim has been ab initio manufactured from cell to finished product at two different production facilities. Comprehensive structural, biological and functional characterization studies were performed to compare Fraven® from two different production sites and its reference product Neupogen® sourced from Turkey. METHODS: Primary and higher-order protein structures were analyzed by high performance liquid chromatography electrospray ionization-time of flight mass spectrometry, circular dichroism, and two-dimensional nuclear magnetic resonance spectroscopy. Isoelectric focusing, SDS-Page, size exclusion chromatography, and related proteins analyses were used to compare impurities. In order to assess functional similarity, surface plasmon resonance (SPR) was used. In vitro cell proliferation assay was also performed to show dose related drug response in NFS-60 cell line. RESULTS: Primary, secondary and tertiary structures of biosimilar Fraven® manufactured at both sites were found to be highly similar to the reference Neupogen®. Product related substances and impurities were also highly similar to the reference. Comparability of GCSF receptor binding affinities of each product was shown using the KD values of SPR analysis. In vitro cell proliferation similarity was also evaluated and proven by PLA. CONCLUSION: Based on the similarity assessment, despite being manufactured at two different production sites, biosimilar Fraven® is highly similar to the reference product Turkey originated Neupogen®.

Synthetic Approaches to the New Drugs Approved During 2017.

New drugs introduced to the market every year represent privileged structures for particular biological targets. These new chemical entities (NCEs) provide insight into molecular recognition while serving as leads for designing future new drugs. This annual review describes the most likely process-scale synthetic approaches to 31 new chemical entities approved for the first time globally in 2017.

Research progress in the biological activities of 3,4,5-trimethoxycinnamic acid (TMCA) derivatives.

TMCA (3,4,5-trimethoxycinnamic acid) ester and amide are privileged structural scaffolds in drug discovery which are widely distributed in natural products and consequently produced diverse therapeutically relevant pharmacological functions. Owing to the potential of TMCA ester and amide analogues as therapeutic agents, researches on chemical syntheses and modifications have been carried out to drug-like candidates with broad range of medicinal properties such as antitumor, antiviral, CNS (central nervous system) agents, antimicrobial, anti-inflammatory and hematologic agents for a long time. At the same time, SAR (structure-activity relationship) studies have draw greater attention among medicinal chemists, and many of the lead compounds were derived for various disease targets. However, there is an urgent need for the medicinal chemists to further exploit the precursor in developing chemical entities with promising bioactivity and druggability. This review concisely summarizes the synthesis and biological activity for TMCA ester and amide analogues. It also comprehensively reveals the relationship of significant biological activities along with SAR studies.

Quality Comparison of Biosimilar and Copy Filgrastim Products with the Innovator Product.

PURPOSE: Filgrastim, a recombinant human granulocyte-colony stimulating factor, is widely used to treat congenital and acquired neutropenia. Following patent expiration of the innovator filgrastim product, biosimilar filgrastim products have been approved in the EU and shown to be comparable with the innovator with respect to quality, safety and efficacy. In less regulated markets, copy filgrastim products are available but data about their quality are scarce. In the present study, we provide a head-to-head comparative study on the quality of biosimilar and copy filgrastim products. METHODS: Innovator filgrastim product, Neupogen®, two EU-licensed biosimilars, Zarzio® and Tevagrastim®, and two copy filgrastim products, Biocilin® and PDgrastim®, were subjected to peptide mapping, circular dichroism spectroscopy, fluorescence spectroscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis, high performance size-exclusion chromatography, reversed-phase ultra-performance liquid chromatography, endotoxin test, flow imaging microscopy and in vitro potency assay. RESULTS: Zarzio® and Tevagrastim® have comparable quality to Neupogen®, while Biocilin® showed a significantly lower and PDgrastim® a higher specific activity. Moreover, PDgrastim® showed a higher level of impurities and a lower thermo stability than the other products. CONCLUSIONS: Except for the deviating specific activities of the two copy filgrastim products, we found no substantial differences in product quality between the filgrastim products studied.

Influence of Modified Fucoidan and Related Sulfated Oligosaccharides on Hematopoiesis in Cyclophosphamide-Induced Mice.

Immunosuppression derived after cytostatics application in cancer chemotherapy is considered as an adverse side effect that leads to deterioration of quality of life and risk of infectious diseases. A linear sulfated (1→3)-α-l-fucan M-Fuc prepared by chemical modification of a fucoidan isolated from the brown seaweed Chordaria flagelliformis, along with two structurally related synthetic sulfated oligosaccharides, were studied as stimulators of hematopoiesis on a model of cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor (r G-CSF), which is currently applied in medicine to treat low blood neutrophils, was used as a reference. Polysaccharide M-Fuc and sulfated difucoside DS did not demonstrate significant effect, while sulfated octasaccharide OS showed higher activity than r G-CSF, causing pronounced neutropoiesis stimulation. In addition, production of erythrocytes and platelets was enhanced after the octasaccharide administration. The assessment of populations of cells in blood and bone marrow of mice revealed the difference in mechanisms of action of OS and r G-CSF.

Stability of Extemporaneously Prepared Hydroxycarbamide Oral Suspensions.

Hydroxycarbamide, available as tablets, is a pharmacological agent for fetal hemoglobin induction such as sickle cell anemia. The need for alternative dosage form options for patients unable to take tablets led hospital pharmacies to prepare solutions and suspensions. The objective of this study was to determine the stability of hydroxycarbamide in Ora-Plus in combination with either Ora-Sweet or Ora-Sweet SF, Ora-Blend, or Ora-Blend SF suspending agents. The studied samples were compounded into 100-mg/mL suspensions and stored in 60-mL amber glass bottles at room (22°C to 25°C) or refrigerated (4°C to 8°C) temperature. Samples were assayed at each time point out to 120 days by a stability-indicating high-performance liquid chromatography method. The samples were examined for any change in color, odor, visual microbiology, and pH on initial and final day of analysis. At least 90% of hydroxycarbamide concentration remained in all suspensions at the end of the 120-day study period in both conditions. There was no appreciable change in color, odor, or taste. The pH values of suspensions stored at 25°C changed by at least 1 unit at the end of the study period. Based on the data collected, the beyond-use date of these suspensions is 120 days when stored in 60-mL amber glass bottles at both temperature storage conditions.

Rapid formulation assessment of filgrastim therapeutics by a thermal stress test.

The biosimilar versions of recombinant methionyl human granulocyte colony-stimulating factor (rh-Met-G-CSF, filgrastim) are now widely available. Because changes to the formulation often lead to subtle differences, there is a critical need to define techniques to test and insure the quality of these products. The present study was designed to compare formulation and thermal stress stability of filgrastim products. The formulation ingredients including acetate, polysorbate 80, and sorbitol were determined using state-of-the-art validated analytical methods. The formulation pH and osmolality were also measured. Moreover, the stability profiles of 8 filgrastim products using thermal stress at 57 °C for 4 h were assessed by size-exclusion high-performance liquid chromatography (SE-HPLC) and in vitro biological assay. The products had different stability profiles. More stable products were within the specification for formulation and less stable products were beyond the specification limits. Altogether, the results suggest that a short-time stress study at 57 °C and analysis of filgrastim by SE-HPLC could unveil formulation problems and is potentially useful for comparability studies.

[NOTHROMBEL EFFECT ON THE EXPRESSION OF MEMBRANE COMPLEX GPIb-IX-V PLATELETS ACTIVATED BY THROMBIN].

The influence of Nothrombel on the expression of membrane complex GPIb-IX-V of platelets activated by thrombin was studied. It is established that Nothrombel reduced thrombin-induced expression of complex GPIb-IX-V on the membrane of the activated platelets. The inhibitory activity of Nothrombel on the expression of GPIb (CD42b) was comparable to its activity with respect to GPIX (CD42a) and is equal to 43 %. With regard to GPV (CD42d) inhibitory effect of the drug was less pronounced and is equal to 22 %. The possible targets for Nothrombel are activation of thromboxane signaling pathway, as well as GPIb-IX-V receptors of platelets itself.

Hydrophobicity and antioxidant activity acting together for the beneficial health properties of nordihydroguaiaretic acid.

Nordihydroguaiaretic acid (NDGA) and rosmarinic acid (RA), phenolic compounds found in various plants and functional foods, have known antioxidant and anti-inflammatory properties. In the present study, we comparatively investigated the importance of hydrophobicity and oxidisability of NDGA and RA, regarding their antioxidant and pharmacological activities. Using a panel of cell-free antioxidant protocols, including electrochemical measurements, we demonstrated that the anti-radical capacities of RA and NDGA were similar. However, the relative capacity of NDGA as an inhibitor of NADPH oxidase (ex vivo assays) was significantly higher compared to RA. The inhibitory effect on NADPH oxidase was not related to simple scavengers of superoxide anions, as confirmed by oxygen consumption by the activated neutrophils. The higher hydrophobicity of NDGA was also a determinant for the higher efficacy of NDGA regarding the inhibition of the release of hypochlorous acid by PMA-activated neutrophil and cytokine (TNF-α and IL-10) production by Staphylococcus aureus-stimulated peripheral blood mononuclear cells. In conclusion, although there have been extensive studies about the pharmacological properties of NDGA, our study showed, for the first time, the importance not only of its antioxidant activity, but also its hydrophobicity as a crucial factor for pharmacological action.

Rhinocetin, a venom-derived integrin-specific antagonist inhibits collagen-induced platelet and endothelial cell functions.

Snaclecs are small non-enzymatic proteins present in viper venoms reported to modulate hemostasis of victims through effects on platelets, vascular endothelial, and smooth muscle cells. In this study, we have isolated and functionally characterized a snaclec that we named "rhinocetin" from the venom of West African gaboon viper, Bitis gabonica rhinoceros. Rhinocetin was shown to comprise α and ß chains with the molecular masses of 13.5 and 13 kDa, respectively. Sequence and immunoblot analysis of rhinocetin confirmed this to be a novel snaclec. Rhinocetin inhibited collagen-stimulated activation of human platelets in a dose-dependent manner but displayed no inhibitory effects on glycoprotein VI (collagen receptor) selective agonist, CRP-XL-, ADP-, or thrombin-induced platelet activation. Rhinocetin antagonized the binding of monoclonal antibodies against the α2 subunit of integrin α2ß1 to platelets and coimmunoprecipitation analysis confirmed integrin α2ß1 as a target for this venom protein. Rhinocetin inhibited a range of collagen-induced platelet functions such as fibrinogen binding, calcium mobilization, granule secretion, aggregation, and thrombus formation. It also inhibited integrin α2ß1-dependent functions of human endothelial cells. Together, our data suggest rhinocetin to be a modulator of integrin α2ß1 function and thus may provide valuable insights into the role of this integrin in physiological and pathophysiological scenarios, including hemostasis, thrombosis, and envenomation.

Thrombopoietin agonists for the treatment of thrombocytopenia in liver disease and hepatitis C.

Thrombocytopenia is a condition of unusually low level of platelets in blood, resulting from an imbalance between the production and destruction of platelets, and is associated with aplastic anemia, myelodysplasia, and idiopathic thrombocytopenic purpura (ITP). Thrombocytopenia can also be associated with severe chronic liver disease as a result of several factors that may act in concert, including reduced production of the endogenous thrombopoietic growth factor, thrombopoietin (TPO). This article examines the nature of thrombocytopenia, ITP, and TPO.

Bis-epoxyethyl derivatives of distamycin A modified on the amidino moiety: induction of production of fetal hemoglobin in human erythroid precursor cells.

Derivatives of distamycin A modified at the C-terminal amidine moiety and tethered to bis-epoxyethyl moieties at the N-terminal position were tested for their ability to induce erythroid differentiation in the human erythroleukemic cell line K562. None of the compounds without bis-epoxyethyl moiety were active. A comparison of the biological activity of diepoxy compounds containing different non-basic amidine-modified moieties, showed low activity of amidoxime, carbamoyl and N-methyl carbamoyl derivatives as differentiation agents. In contrast, a cyanamidine derivative, compound 3, was able to induce erythroid differentiation of K562 cells. In addition, the cyanamidine derivative 3 was able to induce HbF accumulation following treatment of cultures of erythroid precursor cells isolated from the peripheral blood of normal subjects.

Physicochemical properties, pharmacokinetics, and pharmacodynamics of intravenous hematin: a literature review.

INTRODUCTION: Intravenous (i.v.) hematin has been used in the treatment of acute intermittent porphyria (AIP) since the early 1970s and commercially available as Panhematin (hemin for injection; Ovation Pharmaceuticals, Inc., USA) since 1983, yet no publication to date has attempted to summarize the known pharmacodynamics and toxicological actions of hematin and the implications on treatment. It is the objective of this literature review to identify, consolidate, and summarize the available scientific literature regarding the physicochemical properties, pharmacokinetics, toxicology, and hemostatic effects of i.v. hematin injections. METHODS: A comprehensive search of the available literature was performed and resulting data were summarized. Furthermore, previously unpublished toxicology data extracted from the original New Drug Application were included. RESULTS: Hematin, reconstituted with sterile water, rapidly degrades and it is hypothesized that the degradation products lead to morbidities such as thrombophlebitis, thrombocytopenia, and transient anticoagulation. Reconstitution with human serum albumin produces a well-tolerated hematin preparation and improves its stability significantly. The clearance of i.v. hematin infusions are shown to fit a two-compartment model consisting of a rapid initial rate followed by a slower and prolonged second phase. This model is supported by the evidence demonstrating that hematin is first bound by hemopexin and, upon saturation, second by albumin. The highest i.v. human hematin dose reported in the literature was 12.2 mg/kg (1000 mg) and resulted in acute gastrointestinal pain, paresthesia, and acute tubercular necrosis. The patient's renal function returned to normal over the following 15 hours. CONCLUSION: Hematin, at doses approved by the US Food and Drug Administration, is generally well tolerated. Reconstitution with albumin produces a significantly more stable preparation than reconstitution with sterile water and may lead to a more tolerable administration with less hemostatic interference. Hematin, once administered, is cleared hepatically and is best represented pharmacokinetically by a two-compartment model comprised of a rapid initial phase followed by a slower second phase.

Recent advances in the treatment of thromboembolic diseases: venous thromboembolism.

Venous thromboembolic diseases are the major concern of rising cost of healthcare and are commonest health problem across the globe. Both genetic and acquired risk factors are believed to be strongly linked with these diseases. Commonly encountered problems to the therapy include dose fixing and routine monitoring, yet some serious problems of bleeding also necessitate the immediate need to develop new agents. The review is primarily concerned with the new developments in the treatment of thromboembolic diseases. Therapeutic applications of anticoagulants, antiplatelets, and thrombolytics have been discussed in enough detail.

In vitro procoagulant and anticoagulant properties of Naja naja naja venom.

Bites by the Indian cobra (Naja naja naja) are common in India and Sri Lanka because of its close association with humans. Cobra venoms are complex and contain several toxic components, including neurotoxins that cause post-synaptic neuromuscular blockade with respiratory paralysis and even death. Bites may also cause extensive local necrosis by mechanisms not fully elucidated. Although no significant coagulopathy has been reported, N.n. naja venom can form blood clots in vitro by activating prothrombin as demonstrated by thrombin-specific chromogenic substrate. Scanning electron microscopy demonstrates that the clots formed by venom lack the thin fibrin strands of normal blood clots formed by thromboplastin or glass contact. Rheometry shows that clots formed by venom have abnormally low elasticity over an extended period and then, as the platelets contract, a retarded and more feeble increase in elasticity. Purified N.n. naja venom PLA2 inhibits platelet aggregation in PRP and explains the decreased clot retraction and retarded and compromised elasticity build up. The present study shows that the PLA2 and the prothrombin activator from N.n. naja venom have effects on haemostasis and blood clotting, although such effects are not observed systemically in envenomed humans.

[The application of the endotoxin test for globulin and other blood products].

The application of the endotoxin test for globulin and other blood products were investigated by two different limulus amebocyte lysate (LAL) test methods, colorimetric and kinetic turbidimetric methods, using two endotoxin-specific reagents. By the dilution of the blood products in 40 times or more, spiked endotoxin in the products was recovered accurately showing neither inhibition nor enhancement. The definite difference was not shown between the results obtained by the two LAL test methods. According to the method of the endotoxin test described under General Tests of The Japanese Pharmacopeia (thirteenth edition), JPXIII, the maximum valid dilution (MVD) for these products will be calculated to be 40 or more, so it is capable to measure the endotoxin limit for each product. This study indicates that the endotoxin test is applicable to measure the endotoxin content in globulin and other blood products as an alternative method for the rabbit pyrogen test.

Drugs acting on blood and/or blood forming organs.

Pharmacologic therapy for anemia is oriented toward (1) providing components needed for red blood cell production (vitamin B12 and folic acid), including hemoglobin synthesis (iron and other minerals), and (2) stimulating bone marrow formation of red blood cells. Drugs used to stimulate bone marrow activity will be the focus of this article.