Comparative analytical profiling of bevacizumab biosimilars marketed in India: a national control laboratory study.

In this study, analytical profiling of the bevacizumab (BVZ) biosimilars (N = 3) approved in India were evaluated for charge heterogeneity, isoelectric focusing, aggregation and in vitro potency analysis. The charge variants were characterized using high performance cation-exchange chromatography (CEX-HPLC), capillary zone electrophoresis (CZE) and capillary isoelectric focusing (cIEF). cIEF was also used for estimation of isoelectric point (pI value). In addition, aggregate analysis was done using size exclusion high performance chromatography (SEC-HPLC). The cell-based inhibition of proliferation assay using HUVEC cells, indirect ELISA and Western blot were performed for in vitro biological activity. In addition of cell-based cytotoxicity assay was also performed and found no cytotoxic effect on both HuT78 and WIL2S cells by bevacizumab biosimilars. The significant variations in acidic (p < 0.0001) and basic variants (p < 0.0001), pI value (p = 0.0035), aggregates (p = 0.0306) of biosimilars were found as compared to innovator product; however, cell-based potency analysis (p = 0.6047) and indirect ELISA (p = 0.1611) have shown no significant difference in the biological activity. The banding patterns of all biosimilars in western blot were found similar to the innovator product. The comparatively higher basic variants in the biosimilars were attributing to the high pI value of biosimilars to that of innovator product, although these variations were not affecting the biological activity of the biosimiars. This is a unique study, wherein the independent analysis by a National Control Laboratory (NCL) will not only help the National Regulatory Authority (NRA) to assess the quality and consistency in manufacturing of BVZ biosimilars marketed in India but also facilitate the uptake of BVZ biosimilars, and sustainable access to new medicines against the anti-angiogenic therapy.

A reliable assay for ensuring the biological activity of anti T lymphocyte immunoglobulin as an alternate to compendial flow cytometry method.

The assay of Anti T lymphocyte immunoglobulin for final drug product testing is carried out using flow cytometry on Peripheral Blood Mononuclear Cells (PBMCs) as specified in European and British Pharmacopeia. An alternate assay was developed wherein the potency based quality control evaluation of Anti T lymphocyte immunoglobulin is carried out by measuring complement dependent cytotoxicity (CDC) using fluorescent resazurin dye. The reported bioassay was specific, linear (R2 = 0.98), precise (%GCV for repeatability was 3.54% and intermediate precision was 4.27%) and accurate with relative bias of -5.54%. On the basis of results obtained from the repeated performances on single available product, system suitability criteria and sample acceptance criteria were proposed wherein Slope from 4 PL curve fit results for Reference Standard (RS) should be > 0.9, EC50 for RS should lie between 0.264 and 1.131 µg/ml and fold response should be > 2. Confidence interval range and estimated relative potency range obtained from the method validation were narrower than those mentioned for compendial method.

A comprehensive review on microbial l-asparaginase: Bioprocessing, characterization, and industrial applications.

l-Asparaginase (E.C.3.5.1.1.) is a vital enzyme that hydrolyzes l-asparagine to l-aspartic acid and ammonia. This property of l-asparaginase inhibits the protein synthesis in cancer cells, making l-asparaginase a mainstay of pediatric chemotherapy practices to treat acute lymphoblastic leukemia (ALL) patients. l-Asparaginase is also recognized as one of the important food processing agent. The removal of asparagine by l-asparaginase leads to the reduction of acrylamide formation in fried food items. l-Asparaginase is produced by various organisms including animals, plants, and microorganisms, however, only microorganisms that produce a substantial amount of this enzyme are of commercial significance. The commercial l-asparaginase for healthcare applications is chiefly derived from Escherichia coli and Erwinia chrysanthemi. A high rate of hypersensitivity and adverse reactions limits the long-term clinical use of l-asparaginase. Present review provides thorough information on microbial l-asparaginase bioprocess optimization including submerged fermentation and solid-state fermentation for l-asparaginase production, downstream purification, its characterization, and issues related to the clinical application including toxicity and hypersensitivity. Here, we have highlighted the bioprocess techniques that can produce improved and economically viable yields of l-asparaginase from promising microbial sources in the current scenario where there is an urgent need for alternate l-asparaginase with less adverse effects.

Efficient regioselective acylation of quercetin using Rhizopus oryzae lipase and its potential as antioxidant.

The present investigation describes the regioselective enzymatic acylation of quercetin with ferulic acid using Rhizopus oryzae lipase. Optimization of reaction parameters resulted in 93.2% yield of the ester synthesized using 750IU of lipase in cyclo-octane at a temperature of 45°C. The reaction was successfully carried out upto 25g scale. The ester synthesized was analyzed by (1)H Nuclear magnetic resonance spectroscopy. The ester synthesized (quercetin ferulate) showed higher antiradical activity as compared to ascorbic acid using the 2,2-diphenyl-1-picrylhydrazyl radical method. These results on enzyme-catalyzed acylation of quercetin might be used to prepare and scale-up other flavonoids derivatives.

Purification and characterization of a novel and robust L-asparaginase having low-glutaminase activity from Bacillus licheniformis: in vitro evaluation of anti-cancerous properties.

L-asparaginase having low glutaminase has been a key therapeutic agent in the treatment of acute lymphpoblastic leukemia (A.L.L). In the present study, an extracellular L-asparaginase with low glutaminase activity, produced by Bacillus licheniformis was purified to homogeneity. Protein was found to be a homotetramer of 134.8 KDa with monomeric size of 33.7 KDa and very specific for its natural substrate i.e. L-asparagine. The activity of purified L-asparaginase enhanced in presence of cations including Na+ and K+, whereas it was moderately inhibited in the presence of divalent cations and thiol group blocking reagents. The purified enzyme was maximally active over the range of pH 6.0 to 10.0 and temperature of 40°C and enzyme was stable maximum at pH 9.0 and -20°C. CD spectra of L-asparaginase predicted the enzyme to consist of 63.05% α-helix and 3.29% ß-sheets in its native form with T222 of 58°C. Fluorescent spectroscopy showed the protein to be stable even in the presence of more than 3 M GdHCl. Kinetic parameters Km, Vmax and kcat of purified enzyme were found as 1.4×10(-5) M, 4.03 IU and 2.68×10(3) s(-1), respectively. The purified L-asparaginase had cytotoxic activity against various cancerous cell lines viz. Jurkat clone E6-1, MCF-7 and K-562 with IC50 of 0.22 IU, 0.78 IU and 0.153 IU respectively. However the enzyme had no toxic effect on human erythrocytes and CHO cell lines hence should be considered potential candidate for further pharmaceutical use as an anticancer drug.

Eco-friendly methodology for efficient synthesis and scale-up of 2-ethylhexyl-p-methoxycinnamate using Rhizopus oryzae lipase and its biological evaluation.

Lipase-mediated synthesis of phenolic acid esters is a green and economical alternative to current chemical methods. Octyl methoxycinnamate, an important UVB-absorbing compound, was synthesized by the esterification of p-methoxycinnamic acid with 2-ethyl hexanol using Rhizopus oryzae lipase. A molar ratio of 1:2 of p-methoxycinnamic acid and 2-ethyl hexanol was found to give an optimum yield using cyclo-octane (50 ml) as reaction solvent, at a temperature of 45 °C, and 750 U of lipase, resulting in a yield of 91.3 % in 96 h. This reaction was successfully scaled up to 400-ml reaction size where 88.6 %bioconversion was achieved. The synthesized compound was found to have superior antioxidant activity as compared to ascorbic acid. The synthesized compound also exhibited good antimicrobial activity against Escherichia coli, Klebsiella pneumonia, Salmonella typhi, Staphylococcus aures, Candida albicans (yeast), Aspergillus niger, Alternaria solani, and Fussarium oxysporum by well diffusion method in terms of zone of inhibitions (in mm).

A rapid, efficient and sensitive plate assay for detection and screening of l-asparaginase-producing microorganisms.

l-Asparaginase-producing microbes are conventionally screened on phenol red l-asparagine-containing plates. However, sometimes the contrast of the zone obtained (between yellow and pink) is not very sharp and distinct. In the present investigation, an improved method for screening of the microorganisms producing extracellular l-asparaginase is reported wherein bromothymol blue (BTB) is incorporated as pH indicator in l-asparagine-containing medium instead of phenol red. Plates containing BTB at acidic pH are yellow and turn dark blue at alkaline pH. Thus, a dense dark blue zone is formed around microbial colonies producing l-asparaginase, differentiating between enzyme producers and non-producers. The present method is more sensitive and accurate than the conventional method for screening of both fungi and bacteria producing extracellular l-asparaginase. Furthermore, BTB gives a transient green colour at neutral pH (7.0) and dark blue colour at higher pH 8.0-9.0, indicating the potency of the microorganism for l-asparaginase production.

Efficient production of L-asparaginase from Bacillus licheniformis with low-glutaminase activity: optimization, scale up and acrylamide degradation studies.

L-Asparaginase has potential as an anti-cancer drug and for prevention of acrylamide formation in fried and baked foods. Production of the enzyme by Bacillus licheniformis (RAM-8) was optimized by process engineering using a statistical modeling approach and a maximum yield of 32.26 IU/ml was achieved. The L-asparaginase exhibited glutaminase activity of only 0.8 IU/ml and would therefore be less prone to cause the side effects associated with asparaginase therapy compared to enzyme preparations with higher glutaminase activities. When production was carried out in a 30-L bioreactor, enzyme production reached 29.94 IU/ml in 15 h. The enzyme inhibited poly-acrylamide formation in 10% acrylamide solution and reduced acrylamide formation in fried potatoes by 80%.