A battery of assays for chasing ricin and its activity

Ricin, a type-2 Ribosome-Inactivating Protein (RIP), is a dangerous biotoxin derived from castor plant seeds. It is classified as a Schedule 1 agent by the Chemical Weapon Convention (CWC) and a Category B agent by the Biological and Toxin Weapon Convention (BTWC). Despite their high toxicity, castor seed plants are widely used for the production of castor oil and in folk medicine systems for the treatment of various diseases. Due to the lack of a Food and Drug Administration (FDA) approved medication, early detection of biologically active ricin is critical for implementing suitable countermeasures in time to avert casualties. It is required to employ an integrated approach to distinguish between pure and crude ricin as well as active/inactive ricin. In the present study, a series of bioassays were performed to identify biologically active ricin and its different forms. This assessment included both field and lab-based assays to detect and differentiate different isoforms of ricin. The assays used are the lateral flow assay (LFA), hemagglutination assay (HA), In-vitro translational system (IVTS), cytotoxicity assay (CA), and mouse protection assay (MPA). Considering the ricin-contaminated scenario, the first step was to qualitatively determine the presence of ricin using LFA. Following that, a HA was optimized to differentiate between crude and pure ricin. In addition to this, the assay was also able to differentiate various cultivars and isoforms. IVTS assay was used to identify the enzymatic activity of the ricin A chain that inhibited translational machinery with IC50 (50 % inhibitory concentration) of 11.2 ng/ml. Further neutralization with anti-ricin rabbit polyclonal antibodies (RPAb) confirmed the ricin-mediated translation inhibition and excluded the use of other RIPs (abrin, saproin, and viscumin). Cytotoxicity in HeLa cells was used as a cellular model with an estimated CC50 value (50 % cytotoxic concentration) of 36 ng/ml. The neutralization experiment with RPAb specifically reversed the ricin-induced cytotoxicity. A mouse protection assay was done using 5X LD50 of ricin, which caused mortality within 48 h. RPAb increased the survival, verdict the presence of ricin, and eliminated the presence of related RIPs. All the proposed assays suffice the requirement during ricin exposure scenario from the field to the laboratory. These assays are also capable of distinguishing crude/pure/cultivars, and isoforms of ricin. During an emergency, a combination of these assays will help us to make faster decisions and increase the therapeutic time window for treatment.

Recent progress in drying technologies for improving the stability and delivery efficiency of biopharmaceuticals

Background

Most biopharmaceuticals are developed in liquid dosage forms that are less stable than solid forms. To ensure the stability of biopharmaceuticals, it is critical to use an effective drying technique in the presence of an appropriate stabilizing excipient. Various drying techniques are available for this purpose, such as freeze drying or lyophilization, spray drying, spray freeze-drying, supercritical fluid drying, particle replication in nonwetting templates, and fluidized bed drying.

Area covered

In this review, we discuss drying technologies and their applications in the production of stable solid-state biopharmaceuticals, providing examples of commercially available products or clinical trial formulations. Alongside this, we also review how different analytical methods may be utilized in the evaluation of aerosol performance and powder characteristics of dried protein powders. Finally, we assess the protein integrity in terms of conformational and physicochemical stability and biological activity.

Expert opinion

With the aim of treating either infectious respiratory diseases or systemic disorders, inhaled biopharmaceuticals reduce both therapeutic dose and cost of therapy. Drying methods in the presence of optimized protein/stabilizer combinations, produce solid dosage forms of proteins with greater stability. A suitable drying method was chosen, and the process parameters were optimized based on the route of protein administration. With the ongoing trend of addressing deficiencies in biopharmaceutical production, developing new methods to replace conventional drying methods, and investigating novel excipients for more efficient stabilizing effects, these products have the potential to dominate the pharmaceutical industry in the future.

Recent advances in the analysis of therapeutic proteins by capillary and microchip electrophoresis

The development of therapeutic proteins and peptides is an expensive and time-intensive process. Biologics, which have become a multi-billion dollar industry, are chemically complex products that require constant observation during each stage of development and production. Post-translational modifications along with chemical and physical degradation from oxidation, deamidation, and aggregation, lead to high levels of heterogeneity that affect drug quality and efficacy. The various separation modes of capillary electrophoresis (CE) are commonly utilized to perform quality control and assess protein heterogeneity. This review attempts to highlight the most recent developments and applications of CE separation techniques for the characterization of protein and peptide therapeutics by focusing on papers accepted for publication in the in the two-year period between January 2012 and December 2013. The separation principles and technological advances of CE, capillary gel electrophoresis, capillary isoelectric focusing, capillary electrochromatography and CE-mass spectrometry are discussed, along with exciting new applications of these techniques to relevant pharmaceutical issues. Also included is a small selection of papers on microchip electrophoresis to show the direction this field is moving with regards to the development of inexpensive and portable analysis systems for on-site, high-throughput analysis.