102 research outputs found
Variability in the α and β anomer content of commercially available lactose
Lactose, a disaccharide is a ubiquitous excipient in many pharmaceutical formulations which exists in two anomeric forms; either as - or -lactose. The anomers have different properties which can affect their application. Nevertheless, batches of lactose products are widely produced by many manufacturers, and is available in many grades. However, the anomeric content of these batches has not been accurately characterized and reported previously. Therefore, the aim of this study was to analyse a set of 19 commercially available samples of lactose using a novel H1-NMR technique to establish a library showing the anomeric content of a large range of lactose products. The lactose samples were also analysed by DSC. The anomeric content of the -lactose monohydrate samples were found to vary by more than 10%, which might in_uence bioavailability from ^nal formulations. The data showed that there is a need to determine and monitor the anomeric content of lactose and this should be a priority to both manufacturers and formulators of medicines
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Non-salt based co-amorphous formulation produced by freeze-drying
Amino acids-based co-amorphous system (CAM) has shown to be a promising approach to overcome the dissolution challenge of biopharmaceutics classification system class II drugs. To date, most CAM formulations are based on salt formation at a 1:1 M ratio and are prepared by mechanical activation. However, its use in medicinal products is still limited due to the lack of in-depth understanding of non-ionic based molecular interactions. There are also limited studies on the effect of drug-to-co-former ratio, the development of more scalable, less aggressive, manufacturing processes such as freeze drying and its dissolution benefits. This work aims to investigate the effect of the ratio of tryptophan (a model non-ionic amino acid) to indomethacin (a model drug) on a non-salt-based CAM prepared via freeze-drying with the tert-butyl alcohol-water cosolvent system. The CAM material was systemically characterized at various stages of the freeze-drying process using DSC, UV-Vis, FT-IR, NMR, TGA and XRPD. Dissolution performance and physical stability upon storage were also investigated. Freeze-drying using the cosolvent system has been successfully shown to produce CAMs. The molecular interactions involving H-bonding, H/π and π-π between compounds have been confirmed by FT-IR and NMR. The drug release rate for formulations with a 1.5:1 drug: amino acid molar ratio (or 1:0.42 wt ratio) or below is found to be significantly improved compared to the pure crystalline drug. Furthermore, formulation with a 2.3:1 drug:amino acid molar ratio (or 1:0.25 wt ratio) or below have shown to be physically stable for at least 9 months when stored at dry condition (5% relative humidity, 25 °C) compared to the pure amorphous indomethacin. We have demonstrated the potential of freeze-drying using tert-butyl alcohol-water cosolvent system to produce an optimal non-salt-based class II drug-amino acid CAM
Detect and avoid considerations for safe sUAS operations in urban environments
Operations involving small Unmanned Aerial Systems (sUAS) in urban environments are occurring ever more frequently as recognized applications gain acceptance, and new use cases emerge, such as urban air mobility, medical deliveries, and support of emergency services. Higher demands in these operations and the requirement to access urban airspace present new challenges in sUAS operational safety. The presence of Detect and Avoid (DAA) capability of sUAS is one of the major requirements to its safe operation in urban environments according to the current legislation, such as the CAP 722 in the United Kingdom (UK). The platform or its operator proves a full awareness of all potential obstacles within the mission, maintains a safe distance from other airspace users, and, ultimately, performs Collision Avoidance (CA) maneuvers to avoid imminent impacts. Different missions for the defined scenarios are designed and performed within the simulation model in Software Tool Kit (STK) software environment, covering a wide range of practical cases. The acquired data supports assessment of feasibility and requirements to real-time processing. Analysis of the findings and simulation results leads to a holistic approach to implementation of sUAS operations in urban environments, focusing on extracting critical DAA capability for safe mission completion. The proposed approach forms a valuable asset for safe operations validation, enabling better evaluation of risk mitigation for sUAS urban operations and safety-focused design of the sensor payload and algorithms
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Solid-state epimerisation and disproportionation of pilocarpine HCl: why we need a 5-stage approach to validate melting point measurements for heat-sensitive drugs
Melting points for new drugs are reported in regulatory documents, e.g. investigational brochures, and frequently in published research; however, the authors do not typically consider that heat-induced degradation can affect the melting point measurement. Applying a single heating rate is not adequate, and thus many melting points in the literature and regulatory documentation are not valid. Our aim was to validate a five-stage approach for the melting point measurement of heat-sensitive drugs. These stages are; (1) observe melting; (2) record mass loss; (3) measure melting points at different heating rates; (4) characterise degradation and (5) test for potential isomerisation. Applying this approach to pilocarpine HCl illustrated the sensitivity of a melting point to thermal degradation. Due to salt disproportionation & loss of HCl gas, pilocarpine�s melting point decreased by 14 °C when the heating rate was lowered from 20 to 1 °C/min. Epimerization occurred before melting was reached. Increasing the heating rate diminished disproportionation; however, this did not remove epimerization. Thus, the melting point of pilocarpine HCl of 205.5 ± 0.4 °C measured at 20 °C/min represents the melt of a racemic mixture containing inactive isopilocarpine. Heating above the melting point accelerated degradation, a rate of 5 °C/min recovered just 38 ± 1 of pilocarpine. Such data predicted a shelf-life of 6.6 years. Pilocarpine successfully validated the multistage approach by providing new knowledge concerning its thermal stability. Our 5-stage approach must be applied to all new drugs especially if their formulation requires heat. For example, thermal stability is an infrequently considered pre-requisite in the emerging field of 3D printing
Laser-cutting: A Novel Alternative Approach for Point-of-Care Manufacturing of Bespoke Tablets.
A novel subtractive manufacturing method to produce bespoke tablets with immediate and extended drug release is presented. This is the first report on applying fusion laser cutting to produce bespoke furosemide solid dosage forms based on pharmaceutical-grade polymeric carriers. Cylindric tablets of different sizes were produced by controlling the two-dimensional design of circles of the corresponding diameter. Immediate and extended drug release patterns were achieved by modifying the composition of the polymeric matrix. Thermal analysis and XRD indicated that furosemide was present in an amorphous form. The laser-cut tablets demonstrated no significant drug degradation (<2%) nor the formation of impurities were identified. Multi-linear regression was used to quantify the influences of laser-cutting process parameters (laser energy levels, scan speeds, and the number of laser applications) on the depth of the laser cut. The utility of this approach was exemplified by manufacturing tablets of accurate doses of furosemide. Unlike additive or formative manufacturing, the reported approach of subtractive manufacturing avoids the modification of the structure, e.g., the physical form of the drug or matrix density of the tablet during the production process. Hence, fusion laser cutting is less likely to modify critical quality attributes such as release patterns or drug contents. In a point-of-care manufacturing scenario, laser cutting offers a significant advantage of simplifying quality control and a real-time release of laser-cut products such as solid dosage forms and implants
Transcriptional Landscape of the Prenatal Human Brain
Summary The anatomical and functional architecture of the human brain is largely determined by prenatal transcriptional processes. We describe an anatomically comprehensive atlas of mid-gestational human brain, including de novo reference atlases, in situ hybridization, ultra-high resolution magnetic resonance imaging (MRI) and microarray analysis on highly discrete laser microdissected brain regions. In developing cerebral cortex, transcriptional differences are found between different proliferative and postmitotic layers, wherein laminar signatures reflect cellular composition and developmental processes. Cytoarchitectural differences between human and mouse have molecular correlates, including species differences in gene expression in subplate, although surprisingly we find minimal differences between the inner and human-expanded outer subventricular zones. Both germinal and postmitotic cortical layers exhibit fronto-temporal gradients, with particular enrichment in frontal lobe. Finally, many neurodevelopmental disorder and human evolution-related genes show patterned expression, potentially underlying unique features of human cortical formation. These data provide a rich, freely-accessible resource for understanding human brain development
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