Therapeutic Activity of Type 3 Streptococcus pneumoniae Capsule Degrading Enzyme Pn3PasePaschall, Amy V.; Middleton, Dustin R.; Wantuch, Paeton L.; Avci, Fikri Y.
doi: 10.1007/s11095-020-02960-3pmid: 33140159
PurposeStreptococcus pneumoniae (Spn) serotype 3 (Spn3) is considered one of the most virulent serotypes with resistance to conventional vaccine and treatment regimens. Pn3Pase is a glycoside hydrolase that we have previously shown to be highly effective in degrading the capsular polysaccharide of type 3 Spn, sensitizing it to host immune clearance. To begin assessing the value and safety of this enzyme for future clinical studies, we investigated the effects of high doses of Pn3Pase on host cells and immune system.MethodsWe assessed the enzyme’s catalytic activity following administration in mice, and performed septic infection models to determine if prior administration of the enzyme inhibited repeat treatments of Spn3-challenged mice. We assessed immune populations in mouse tissues following administration of the enzyme, and tested Pn3Pase toxicity on other mammalian cell types in vitro.ResultsRepeated administration of the enzyme in vivo does not prevent efficacy of the enzyme in promoting bacterial clearance following bacterial challenge, with insignificant antibody response generated against the enzyme. Immune homeostasis is maintained following high-dose treatment with Pn3Pase, and no cytotoxic effects were observed against mammalian cells.ConclusionsThese data indicate that Pn3Pase has potential as a therapy against Spn3. Further development as a drug product could overcome a great hurdle of pneumococcal infections.
On the Breakage of High Aspect Ratio Crystals in Filter Beds under Continuous PercolationMahdi, F. M.; Shier, A. P.; Fragkopoulos, I. S.; Carr, J.; Gajjar, P.; Muller, F. L.
doi: 10.1007/s11095-020-02958-xpmid: 33123816
PurposeThis work details experimental observations on the effect of liquid flow percolating through packed beds of crystals to elucidate how the filtration pressure severely alters the size distribution and crystal shape. Pressure filtration is widely used in the pharmaceutical industry, and frequently results in undesired size distribution changes that hinder further processing.MethodsThe percolation methodology presented fixes fluid flow through a bed of crystals, resulting in a pressure over the bed. X-ray computed tomography (XCT) provided detailed observations of the bed structure. Detailed 2D particle size data was obtained using automated microscopy and was analysed using an in-house developed tool.ResultsCrystal breakage is observed when the applied pressure exceeds a critical pressure: 0.5–1 bar for ibuprofen, 1–2 bar for β-L glutamic acid (LGA) and 2–2.5 bar for para amino benzoic acid (PABA). X-ray computed tomography showed significant changes in bed density under the applied pressure. Size analysis and microscope observations showed two modes of breakage: (i) snapping of long crystals and (ii) shattering of crystals.ConclusionLGA and PABA have a similar breakage strength (50 MPa), ibuprofen is significantly weaker (9 MPa). Available breakage strength data may be correlated to the volumetric Gibbs free energy. Data from 12 and 35 mm bed diameters compares well to literature data in a 80 mm filter; the smaller, easy to operate percolation unit is a versatile tool to assess crystal breakage in filtration operations.
Emerging Technologies to Target Drug Delivery to the Skin – the Role of Crystals and Carrier-Based Systems in the Case Study of DapsoneSchneider-Rauber, Gabriela; Argenta, Debora Fretes; Caon, Thiago
doi: 10.1007/s11095-020-02951-4pmid: 33169237
Dapsone (DAP) is a long-established molecule that remains a promising therapeutic agent for various diseases mainly because it combines antimicrobial and anti-inflammatory activities. Its oral application, however, is limited by the dose-dependent hematological side effects that may rise from systemic exposure. As an alternative to overcome this limitation, the administration of DAP to the skin has witnessed prominent interest in the past 20 years, particularly when applied to the treatment of dermatological disorders. In this review, all technological strategies proposed to the topical delivery of DAP are presented. Most of the reported studies have been devoted to the clinical use and safety of a gel formulation containing both solubilized and microcrystalline drug, however, the technological characteristics of such preparation are still missing. In parallel, the incorporation of DAP into vesicular and particulate carriers (e.g. nano- and microemulsions, niosomes, invasomes, bilosomes, cubosomes, solid lipid nanoparticles, nanostructured lipid carriers, polymeric nanocapsules and polymer-lipid-polymer hybrid nanoparticles) appears to be an alternative to provide greater drug release control, enhanced drug solubilization and follicular targeting. Indeed, the main application of DAP topical formulations reported in the literature was the treatment of acne vulgaris, a disease located in the hair follicle. Other diseases affecting different regions of the skin (e.g. cutaneous lupus erythematosus and cutaneous leishmaniasis), however, may also benefit from a topical therapeutic regimen containing DAP. Therefore, the investigation of appendageal route in comparison to passive transmembrane diffusion as a function of targeted disease, as well as pharmacokinetic studies, are perspectives highlighted herein. Such studies may drive future efforts towards the rational development of safe and effective technologies to deliver DAP to the skin.Graphical abstract[graphic not available: see fulltext]
Peptide Isolation via Spray Drying: Particle Formation, Process Design and Implementation for the Production of Spray Dried GlucagonDoerr, Frederik J. S.; Burns, Lee J.; Lee, Becky; Hinds, Jeremy; Davis-Harrison, Rebecca L.; Frank, Scott A.; Florence, Alastair J.
doi: 10.1007/s11095-020-02942-5pmid: 33319329
PurposeSpray drying plays an important role in the pharmaceutical industry for product development of sensitive bio-pharmaceutical formulations. Process design, implementation and optimisation require in-depth knowledge of process-product interactions. Here, an integrated approach for the rapid, early-stage spray drying process development of trehalose and glucagon on lab-scale is presented.MethodsSingle droplet drying experiments were used to investigate the particle formation process. Process implementation was supported using in-line process analytical technology within a data acquisition framework recording temperature, humidity, pressure and feed rate. During process implementation, off-line product characterisation provided additional information on key product properties related to residual moisture, solid state structure, particle size/morphology and peptide fibrillation/degradation.ResultsA psychrometric process model allowed the identification of feasible operating conditions for spray drying trehalose, achieving high yields of up to 84.67%, and significantly reduced levels of residual moisture and particle agglomeration compared to product obtained during non-optimal drying. The process was further translated to produce powders of glucagon and glucagon-trehalose formulations with yields of >83.24%. Extensive peptide aggregation or degradation was not observed.ConclusionsThe presented data-driven process development concept can be applied to address future isolation problems on lab-scale and facilitate a systematic implementation of spray drying for the manufacturing of sensitive bio-pharmaceutical formulations.
Simultaneous Pharmacokinetic Analysis of Nitrate and its Reduced Metabolite, Nitrite, Following Ingestion of Inorganic Nitrate in a Mixed Patient PopulationCoggan, Andrew R.; Racette, Susan B.; Thies, Dakkota; Peterson, Linda R.; Stratford, Robert E.
doi: 10.1007/s11095-020-02959-wpmid: 33140122
PurposeThe pharmacokinetic properties of plasma NO3− and its reduced metabolite, NO2−, have been separately described, but there has been no reported attempt to simultaneously model their pharmacokinetics following NO3− ingestion. This report describes development of such a model from retrospective analyses of concentrations largely obtained from primary endpoint efficacy trials.MethodsLinear and non-linear mixed effects analyses were used to statistically define concentration dependency on time, dose, as well as patient and study variables, and to integrate NO3− and NO2− concentrations from studies conducted at different times, locations, patient groups, and several studies in which sample range was limited to a few hours. Published pharmacokinetic studies for both substances were used to supplement model development.ResultsA population pharmacokinetic model relating NO3− and NO2− concentrations was developed. The model incorporated endogenous levels of the two entities, and determined these were not influenced by exogenous NO3− delivery. Covariate analysis revealed intersubject variability in NO3− exposure was partially described by body weight differences influencing volume of distribution. The model was applied to visualize exposure versus response (muscle contraction performance) in individual patients.ConclusionsExtension of the present first-generation model, to ultimately optimize NO3− dose versus pharmacological effects, is warranted.
Sedimentation Velocity Analytical Ultracentrifugation Analysis of Marketed Rituximab Drug Product Size DistributionPatil, Sharadrao M.; Nguyen, John; Keire, David A.; Chen, Kang
doi: 10.1007/s11095-020-02961-2pmid: 33155155
PurposeAnalytical methods suitable for intact drug products are often necessary to evaluate the equivalence in physicochemical properties between two drug products (DP) containing the same drug substance (DS), e.g., an innovator biologic drug and its proposed biosimilar. Analytical Ultracentrifugation (AUC) is a biophysics technique applied to the analysis of size and shape of biomolecules. However, the application of AUC to formulated monoclonal antibody (mAb) DP at high concentration has not been reported.MethodsA sedimentation velocity (SV) AUC procedure with a short-pathlength centerpiece was applied to two marketed rituximab DPs, Rituxan® (US) and Reditux® (India), without any buffer exchange or dilution. Detailed precision analysis was performed.ResultsHighly reproducible sedimentation coefficient values (S) and peak areas were obtained for the dominant (> 84%) monomeric rituximab peak. The minor mAb fragment peaks had large variation in both S values and peak areas (3–12%). The identification of oligomer peaks was only reproducible once the abundance was higher than 2%.ConclusionsSV-AUC provides an orthogonal characterization tool for protein size distribution, composition and assay, which could be informative for biosimilar drug developers who mostly only have access to formulated mAb. However, AUC needs thorough validation on its accuracy, precision and sensitivity.