Taylor Dispersion Analysis (TDA) is explored to measure the hydrodynamic sizes of full and half generation PAMAM dendrimers up to generation 4.5 in various buffer solutions. A method was used to minimize the interaction between the capillary and cationic dendrimers.
View Article and Find Full Text PDFThe U.S. Maternal Hair Index was designed by the National Sheep Improvement Program (NSIP) to increase total weight of lamb weaned per ewe lambing (TW).
View Article and Find Full Text PDFThe viscoelastic nature of polymeric formulations utilised in drug products imparts unique thermomechanical attributes during manufacturing and over the shelf life of the product. Nevertheless, it adds to the challenge of understanding the precise mechanistic behaviour of the product at the microscopic and macroscopic level during each step of the process. Current thermomechanical and rheological characterisation techniques are limited to assessing polymer performance to a single phase and are especially hindered when the polymers are undergoing thermomechanical transitions.
View Article and Find Full Text PDFBiotechnol Bioeng
September 2021
An 8 ton per year manufacturing facility is described based on the framework for integrated and continuous bioprocessing (ICB) common to all known biopharmaceutical implementations. While the output of this plant rivals some of the largest fed-batch plants in the world, the equipment inside the plant is relatively small: the plant consists of four 2000 L single-use bioreactors and has a maximum flow rate of 13 L/min. The equipment and facility for the ICB framework is described in sufficient detail to allow biopharmaceutical companies, vendors, contract manufacturers to build or buy their own systems.
View Article and Find Full Text PDFPurpose: The aim of this Phase 1, open-label, positron emission tomography (PET) study was to determine the degree of striatal D/D receptor occupancy induced by the serotonin-dopamine activity modulator, brexpiprazole, at different single dose levels in the range 0.25-6 mg.
Methods: Occupancy was measured at 4 and 23.
A triblock ESE copolymer (ESE, S = styrene oxide and E = ethylene oxide) was synthesised by sequential oxyanionic copolymerisation of styrene oxide followed by ethylene oxide. Light scattering studies demonstrated a shape transition from spherical micelles to worm-like micelles above a critical temperature of approximately 18 °C. Taylor dispersion analysis (TDA) also indicated a size growth when the temperature increased from 25 to 40 °C due to the formation of worm-like micelles.
View Article and Find Full Text PDFPolypharmacy is often needed for the management of cardiovascular diseases and is associated with poor adherence to treatment. Hence, highly flexible and adaptable systems are in high demand to accommodate complex therapeutic regimens. A novel design approach is employed to fabricate highly modular 3D printed "polypill" capsules with bespoke release patterns for multiple drugs.
View Article and Find Full Text PDFUnderstanding peptide self-assembly mechanisms and stability of the formed assemblies is crucial for the development of functional nanomaterials. Herein, we have adopted a rational design approach to demonstrate how a minimal structural modification to a nonassembling ultrashort ionic self-complementary tetrapeptide EK (Phe4) remarkably enhanced the stability of self-assembly into β-sheet nanofibers and induced hydrogelation. This was achieved by replacing flexible phenylalanine residue () by the rigid phenylglycine (), resulting in a constrained analogue EK (Phg4), which positioned aromatic rings in an orientation favorable for aromatic stacking.
View Article and Find Full Text PDFUndersea Hyperb Med
January 2021
Introduction: 122,129 dives by 10,358 recreational divers were recorded by dive computers from 11 manufacturers in an exploratory study of how dive profile, breathing gas (air or nitrox [N2/O2] mixes), repetitive diving, gender, age, and dive site conditions influenced observed decompression sickness (DCSobs). Thirty-eight reports were judged as DCS. Overall DCSobs was 3.
View Article and Find Full Text PDFHypertension and dyslipidaemia are modifiable risk factors associated with cardiovascular diseases (CVDs) and often require a complex therapeutic regimen. The administration of several medicines is commonly associated with poor levels of adherence among patients, to which World Health Organisation (WHO) proposed a fixed-dose combination unit (polypill) as a strategy to improve adherence. In this work, we demonstrate the fabrication of patient-specific polypills for the treatment of CVDs by fused deposition modelling (FDM) 3D printing and introduce a novel solution to meet critical quality attributes.
View Article and Find Full Text PDFCoumarin therapy has been associated with high levels of inter- and intra-individual variation in the required dose to reach a therapeutic anticoagulation outcome. Therefore, a dynamic system that is able to achieve accurate delivery of a warfarin dose is of significant importance. Here we assess the ability of 3D printing to fabricate and deliver tailored individualised precision dosing using in-vitro and in-vivo models.
View Article and Find Full Text PDFFused deposition modelling (FDM) 3D printing has shown the most immediate potential for on-demand dose personalisation to suit particular patient's needs. However, FDM 3D printing often involves employing a relatively large molecular weight thermoplastic polymer and results in extended release pattern. It is therefore essential to fast-track drug release from the 3D printed objects.
View Article and Find Full Text PDFConventional immediate release dosage forms involve compressing the powder with a disintegrating agent that enables rapid disintegration and dissolution upon oral ingestion. Among 3D printing technologies, the fused deposition modelling (FDM) 3D printing technique has a considerable potential for patient-specific dosage forms. However, the use of FDM 3D printing in tablet manufacturing requires a large portion of polymer, which slows down drug release through erosion and diffusion mechanisms.
View Article and Find Full Text PDFIn this study we explore the preparation of core-crosslinked micelles of linear-dendritic methoxy-poly(ethylene glycol) (MPEG)-co-poly(ester-sulfide) (PES) polymers to improve the stability of such polymeric micelle systems against premature disintegration and drug release. A series of MPEG-PES copolymers were synthesised via stepwise reactions of acetylation and thiol-ene photoreaction. Surface tension measurement showed that the copolymers with ethenyl surface groups could self-associate in dilute aqueous solutions to form micelles.
View Article and Find Full Text PDFThere is a need to understand the nature of aggregation of cyclodextrins (CDs) with guest molecules in increasingly complex formulation systems. To this end an innovative application of Taylor dispersion analysis (TDA) and comparison with dynamic light scattering (DLS) have been carried out to probe the nature of ICT01-2588 (ICT-2588), a novel tumor-targeted vascular disrupting agent, in solvents including a potential buffered formulation containing 10% hydroxypropyl-β-cyclodextrin. The two hydrodynamic sizing techniques give measurement responses are that fundamentally different for aggregated solutions containing the target molecule, and the benefits of using TDA in conjunction with DLS are that systems are characterised through measurement of both mass- and z-average hydrodynamic radii.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
October 2016
Globular proteins are important both as therapeutic agents and excipients. However, their fragile native conformations can be denatured during pharmaceutical processing, which leads to modification of the surface energy of their powders and hence their performance. Lyophilized powders of hen egg-white lysozyme and β-galactosidase from Aspergillus oryzae were used as models to study the effects of mechanical denaturation on the surface energies of basic and acidic protein powders, respectively.
View Article and Find Full Text PDFIt is important for the formulators of biopharmaceuticals to predict the folding-unfolding transition of proteins. This enables them to process proteins under predetermined conditions, without denaturation. Depending on the apparent denaturation temperature (Tm) of lysozyme, we have derived an equation describing its folding-unfolding transition diagram.
View Article and Find Full Text PDFBulk crystallisation of protein therapeutic molecules towards their controlled drug delivery is of interest to the biopharmaceutical industry. The complexity of biotherapeutic molecules is likely to lead to complex material properties of crystals in the solid state and to complex transitions. This complexity is explored using batch crystallised lysozyme as a model.
View Article and Find Full Text PDFBackground: This post hoc analysis assessed the safety, tolerability and effectiveness of long-term treatment with aripiprazole adjunctive to either bupropion or selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) in patients with major depressive disorder (MDD).
Methods: Data from de novo patients (did not participate in 2 previous studies) in a 52-week, open-label safety study of adjunctive aripiprazole after documented inadequate response to 1-4 antidepressant treatments (ADTs; SSRI, SNRI, or bupropion) were analyzed post hoc. Assessments included safety and tolerability, sexual functioning (Massachusetts General Hospital Sexual Functioning Inventory [MGH-SFI]) and Clinical Global Impressions-Severity (CGI-S).
Using HPLC chiral separation screening, various columns representing the polysaccharide, macrocyclic antibiotic and brush classes were assessed in multiple chromatographic modes for the separation of evacetrapib, a potential cardiovascular drug, from its enantiomer, two diastereomers and several impurities. Screening data consistently pointed to the brush-type Whelk-O 1 chiral column as most promising for this task. A systematic separation optimization process is outlined using the (S,S) Whelk-O 1 chiral column, first for the resolution of the isomers, and later including six potential impurities.
View Article and Find Full Text PDFAn on-line analytical method based on transmission near-infrared spectroscopy (NIRS) for the quantitative determination of water concentrations (in parts per million) was developed and applied to the manufacture of a pharmaceutical intermediate. Calibration models for water analysis, built at the development site and applied at the manufacturing site, were successfully demonstrated during six manufacturing runs at a 250-gallon scale. The water measurements will be used as a forward-processing control point following distillation of a toluene product solution prior to use in a Grignard reaction.
View Article and Find Full Text PDFJ Child Adolesc Psychopharmacol
October 2013
Objective: The purpose of this study was to evaluate the impact of prior antipsychotic exposure (PAE) on safety and tolerability outcomes in pediatric subjects receiving aripiprazole treatment.
Methods: This study was a post-hoc analysis of pooled data from two 8-week, double-blind, randomized, placebo-controlled studies evaluating aripiprazole for the treatment of irritability in pediatric subjects with autistic disorder, aged 6-17 years. Subjects were stratified by PAE; adverse events (AEs), and changes in weight, and metabolic measures were evaluated.
This 24-week, open-label, Phase Ib, parallel-arm, multiple-dose trial assessed the pharmacokinetics, safety and tolerability of a once-monthly injection of aripiprazole (aripiprazole once-monthly) in 41 subjects with schizophrenia. The objective was to determine if aripiprazole plasma concentrations (at doses of 200, 300 and 400mg) were within the therapeutic range observed for the oral tablet (10-30 mg). Completion rates were 36.
View Article and Find Full Text PDFJ Am Acad Child Adolesc Psychiatry
July 2013
Objective: In adults with chronic schizophrenia, most symptom decreases occur in the first few weeks of antipsychotic treatment, and nonresponse at week 2 predicts a later nonresponse. The trajectory of antipsychotic response and the predictive value of early antipsychotic effects were investigated for ultimate outcome in adolescent schizophrenia, where such data are still lacking.
Method: This post hoc analysis of a 6-week, randomized, double-blinded trial of aripiprazole (n = 196) versus placebo (n = 98) evaluated if adolescents 13 to 17 years old with schizophrenia exhibited substantial symptomatic improvement to aripiprazole in the first few treatment weeks and whether early response (ER) versus early nonresponse (ENR) predicted clinically relevant outcomes.