Development and validation of a stability-indicating RP-HPLC method for the identification, determination of related substances and assay of dimethyl fumarate in drug substance.

OBJECTIVE: The objective of current study was to develop and validate a short, economical, accurate, precise stability-indicating RP-HPLC method for identification, quantitation of related substances (fumaric acid and mono methyl fumarate) and assay of dimethyl fumarate (DMF) drug substance. MATERIAL AND METHODS: The RP-HPLC method was developed by using liquid chromatography (waters 2695 with PDA detector & Agilent 1200 with DAD) with Symmetry C18 column. Pharmaceutical grade of high pure materials of DMF, MMF, FA and HPLC grade water, acetonitrile and orthophosphoric acid were used for this study. The mobile phase consists of 0.1% of ortho-phosphoric acid in water: acetonitrile (55:45% v/v). RESULTS: The developed method was validated according to ICH guidelines. To prove the stability indicating potential, stress studies performed using acid, base, peroxide and thermal. After sufficient exposure, these solutions were injected in to HPLC and found that all degradants formed during stress study were well separated from the main peak and resolution between all impurities was more than ICH requirements. CONCLUSION: A simple, short and stability indicating RP-HPLC method was developed and validated for simultaneous estimation of DMF and its related substances in drug substance. Based on literature survey it was evident that many methods were published for determination of DMF individually or its related substances, however short run time methods were not available for simultaneous estimation of DMF and its related substances. The intended method would support to industries for quick quantitation of DMF and its related substances without compromising quality parameters like precision and accuracy.

Influenza subunit vaccine coated microneedle patches elicit comparable immune responses to intramuscular injection in guinea pigs.

Delivery of influenza vaccine using innovative approaches such as microneedles has been researched extensively in the past decade. In this study we present concentration followed by formulation and coating of monobulks from 2008/2009 seasonal vaccine on to 3M's solid microstructured transdermal system (sMTS) by a GMP-scalable process. The hemagglutinin (HA) in monobulks was concentrated by tangential flow filtration (TFF) to achieve HA concentrations as high as 20mg/ml. The stability of the coated antigens was evaluated by the functional assay, single radial immunodiffusion (SRID). The data generated show stability of the coated antigen upon storage at 4°C and room temperature in the presence of desiccant for at least 8 weeks. Freeze-thaw stability data indicate the stability of the coated antigen in stressed conditions. The vaccine coated microstructures were evaluated in vivo in a guinea pig model, and resulted in immune titers comparable to the traditional trivalent vaccine administered intramuscularly. The data presented indicate the potential use of the technology in delivery of influenza vaccine. This paper also addresses the key issues of stability of coated antigen, reproducibility and scalability of the processes used in preparation of influenza vaccine coated microneedle patches that are important in developing a successful product.

MOVAS-1 cell line: a new in vitro model of vascular calcification.

Vascular calcification has severe clinical consequences in a number of diseases, including diabetes, atherosclerosis and end-stage renal disease. The in vitro calcification of primary mouse, human and bovine vascular smooth muscle cells (VSMCs) is commonly employed to examine the mechanisms of vascular calcification. However, to date, no published studies have utilised a murine cell line to investigate this process. In the present study, we aimed to determine whether the mouse VSMC line MOVAS-1 can calcify in vitro. We established that the calcification of MOVAS-1 cells can be induced in the presence of calcifying medium (containing ß-glycerophosphate and ascorbic acid), as detected by Alizarin Red and von Kossa staining, and quantification of calcium deposition and alkaline phosphatase activity. We also showed that the time course of MOVAS-1 calcification is comparable to that of the primary murine aortic VSMCs, establishing the MOVAS-1 cells as a feasible and relevant model. Significant increases in the mRNA expression profile of key genes associated with vascular calcification (Ocn, Akp2 and PiT-1) were observed in MOVAS-1 cells cultured under calcifying conditions, with similar changes in expression in murine aortic VSMCs. Furthermore, a significant reduction in calcification was observed in MOVAS-1 cells following treatment with levamisole and etidronate, known inhibitors of calcification. In conclusion, we demonstrated that the MOVAS-1 line is a reliable, convenient and economical system in which to investigate vascular calcification in vitro, and will make a useful contribution to increasing our understanding of this pathological process.

Antiangiogenic gene therapy with systemically administered sFlt-1 plasmid DNA in engineered gelatin-based nanovectors.

This study examined the potential of engineered gelatin-based nanoparticulate vectors for systemic delivery of therapeutic genes to human solid tumor xenografts in vivo. Plasmid DNA encoding for the soluble form of the extracellular domain of vascular endothelial growth factor receptor-1 (VEGF-R1 or sFlt-1) was encapsulated in the control and poly(ethylene glycol) (PEG)-modified gelatin-based nanoparticles. When the plasmid DNA was delivered in PEG-modified thiolated gelatin nanoparticles, highest levels of sFlt-1 expression was observed in vitro in MDA-MB-435 human breast adenocarcinoma cell line. In addition, upon intravenous administration in female Nu/Nu mice bearing orthotopic MDA-MB-435 breast adenocarcinoma xenografts, efficient in vivo expression of sFlt-1 plasmid DNA was confirmed quantitatively by enzyme-linked immunosorbent assay and qualitatively by Western blot analysis. The expressed sFlt-1 was therapeutically active as shown by suppression of tumor growth and microvessel density measurements. The results of this study show that PEG-modified gelatin-based nanovectors can serve as a safe and effective systemically administered gene delivery vehicle for solid tumor.

Modulation of neonatal rat myeloid kinetics resulting in peripheral neutrophilia by single pulse administration of Rh granulocyte-macrophage colony-stimulating factor and Rh granulocyte colony-stimulating factor.

Rh granulocyte-macrophage (GM) colony-stimulating factor (CSF) and rh granulocyte (G) CSF have been demonstrated to induce proliferation and maturation of myeloid stem cells and release of mature polymorphonucleocytes (PMNs) from human and animal adult bone marrows. Unfortunately, reduced bone marrow progenitor cells, neutrophil storage pool (NSP) depletion and peripheral neutropenia are characteristic of human and animal newborn bone marrows. We investigated the effect of administering intraperitoneal rhGM-CSF and rhG-CSF to Sprague-Dawley newborn rats (less than 36 h). Newborn rats treated with intraperitoneal CSF (3.0 micrograms/kg) demonstrated significant leukocytosis at 6 and 24 h: rhGM-CSF vs. control, WBC (10(3)/mm3), at 6 h, 8.0 +/- 0.5 vs 4.3 +/- 0.9 (p less than or equal to 0.003), and at 24 h, 7.7 +/- 1.7 vs. 3.8 +/- 0.2 (p less than or equal to 0.008); rhG-CSF vs. control WBC (10(3)/mm3) at 6 h, 6.6 +/- 1.2 vs 4.3 +/- 0.1 (p less than or equal to 0.03), and at 24 h, 8.1 +/- 0.2 vs. 3.75 +/- 0.2 (p less than or equal to 0.003). The absolute neutrophil count was also significantly elevated at 6 h following intraperitoneal CSF (3.0 micrograms/kg): RhGM-CSF vs. control 1,827 +/- 25 vs. 379 +/- 10 (p less than or equal to 0.001); rhG-CSF vs. control, 1,698 +/- 40 vs. 371 +/- 10.1 (p less than or equal to 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Prophylactic or simultaneous administration of recombinant human granulocyte colony stimulating factor in the treatment of group B streptococcal sepsis in neonatal rats.

Despite the emergence of newer antibiotic treatments, group B streptococcal infection still carries a high mortality rate in the newborn and is characterized by reduced neutrophil proliferative pools, neutrophil storage pools, neutropenia, and polymorphonuclear cell dysfunction. Recombinant human granulocyte-colony stimulating factor (rhG-CSF) has recently been demonstrated to induce neutrophilia and modulate neutrophil proliferative pools and neutrophil storage pools in the newborn rat. We therefore investigated the adjuvant effect of rhG-CSF given to group B streptococcus (GBS) septic Sprague-Dawley newborn (less than 36 h) rats treated with and without antibiotic therapy. After inoculation of GBS, a GBS survival curve established the LD50 at 50 h to be approximately 3 X 10(6) organisms/gm. Newborn rats were divided into four treatment groups after GBS inoculation. rhG-CSF was administered at the same time as GBS inoculation. At 24 h, there was approximately 100% survival in all groups. However, by 72 h after GBS inoculation, there was a significant difference in survival. Group 1, PBS/Alb, had a survival rate of 4%; group 2, rhG-CSF, 9%; group 3, antibiotics, 28%; and group 4, antibiotics plus rhG-CSF, 91% (p less than or equal to 0.001). Additionally, when rhG-CSF was administered prophylactically (6 h before GBS), a similar significant synergistic effect in survival was demonstrated with granulocyte colony stimulating factor plus antibiotics versus antibiotics alone (70 versus 10%) (p less than or equal to 0.01). These preliminary data suggest that either simultaneous or prophylactic pulse administration of rhG-CSF may have a synergistic and protective effect on survival in antibiotic-treated experimental GBS in the neonatal rat.

Lymphokines: enhancement by granulocyte-macrophage and granulocyte colony-stimulating factors of neonatal myeloid kinetics and functional activation of polymorphonuclear leukocytes.

Colony-stimulating factors, such as the granulocyte-macrophage and the granulocyte colony-stimulating factors (GM-CSF and G-CSF), are glycoproteins with biologic specificity defined by their ability to support proliferation and differentiation of hematopoietic cells of various lineages. Their physiologic activities include stimulation and proliferation of early stem cell precursors and functional activation of mature peripheral effector cells. Recently produced recombinant human (rh) GM-CSF and G-CSF have been demonstrated to regulate hematopoietic neutrophil progenitor colony growth; to stimulate the release of bone marrow neutrophil storage pools; and to prime mature effector functions, including chemotaxis, oxidative metabolism, phagocytosis, C3bi receptor expression, and antibody-dependent cytotoxicity in adults. We examined the effects of rh-GM-CSF on priming superoxide release and chemotaxis of neonatal (cord) polymorphonuclear leukocytes (PMNs) and of rh-G-CSF and rh-GM-CSF on bone marrow neutrophil egress in the neonatal rat. A time-response evaluation of the effect of rh-GM-CSF revealed enhanced release of superoxide by PMNs. PMN chemotaxis also was enhanced by rh-GM-CSF, with a maximal response occurring earlier than enhanced superoxide release. Intraperitoneal administration of rh-G-CSF or rh-GM-CSF to 1-day-old rats resulted in significant increases in white blood cell counts and significant early neutrophilia. Bone marrow examination revealed that the neutrophilia was secondary to egress and mild depletion of the neutrophil storage pool but that the neutrophil storage pool later returned to normal. These preliminary studies suggest that rh-GM-CSF and rh-G-CSF prime neonatal effector function and induces significant PMN egress and neutrophilia.(ABSTRACT TRUNCATED AT 250 WORDS)