347 research outputs found

    Application of diffusion-edited and solvent suppression 1H NMR to the direct analysis of markers in valerian-hop liquid herbal products

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    This is the peer reviewed version of the following article: Jose M. Prieto, Maria Mellinas-Gomez, Mire Zloh, ‘Application of diffusion-edited and solvent suppression 1H-NMR to the direct analysis of markers in valerian-hop liquid herbal products’, Phytochemical Analysis, Vol 27(2): 100-106, first published online January 13, 2016, which has been published in final form at doi: 10.1002/pca.2603 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving Copyright © 2016 John Wiley & Sons, Ltd.The rising trend to consume herbal products for the treatment and/or prevention of minor ailments together with their chemical and pharmacological complexity means there is an urgent need to develop new approaches to their quality and stability. This work looks at the application of one-dimensional diffusion-edited ¹H NMR spectroscopy (1D DOSY) and ¹H NMR with suppression of the ethanol and water signals to the characterization of quality and stability markers in multicomponent herbal medicines/food supplements. The experiments were performed with commercial tinctures of Valeriana officinalis L. (valerian), expired and non-expired, as well as its combination with Hummulus lupulus L. (hops), which is one of the most popular blends of relaxant herbs. These techniques did not require purification or evaporation of components for the qualitative analysis of the mixture, but only the addition of D2O and TSP. The best diagnostic signals were found at 7 ppm (H-11, valerenic acid), 4.2 ppm (H-1, hydroxyvalerenic acid) and 1.5-1.8 ppm (methyl groups in prenylated moieties, α-acids/prenylated flavones). This work concludes on the potential value of 1D DOSY ¹H NMR to provide additional assurance of quality in complex natural mixtures.Peer reviewe

    Morphology of secretory structures and essential oil composition in Mentha cervina L. from Portugal

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    ABSTRACT: Mentha cervina L. is an aromatic plant that is traditionally used in the Alentejo region of Portugal to flavour food dishes and for the medicinal properties of the essential oil produced in its glandular trichomes. The morphology and distribution of the secretory structures of 20 populations was studied by light and scanning electron microscopy and revealed a great similarity in the type and distribution of glandular and non-glandular trichomes. In addition, two populations were surveyed at different stages of their life cycles. This showed that both maximum trichome density and maximum filling capacity of the glandular trichomes are attained early on. The GC and GC–MS chemical analyses showed that pulegone (62–80%), isomenthone (3–18%) and limonene (3–7%) are the main components of M. cervina essential oils. Cluster analysis of the identified essential oil components revealed a major chemical consistency between the 20 populations evaluate

    Real time Raman imaging to understand dissolution performance of amorphous solid dispersions

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    We have employed for the first time Raman spectroscopic imaging along with multi-variate curve resolution (MCR) analysis to investigate in real time and in-situ the dissolution mechanisms that underpin amorphous solid dispersions, with data being collected directly from the dosage form itself. We have also employed a novel rotating disk dissolution rate (RDDR) methodology to track, through the use of high-performance liquid chromatography (HPLC), the dissolution trends of both drug and polymer simultaneously in multi-component systems. Two formulations of poorly water-soluble felodipine in a polymeric matrix of copovidone VA64 which have different drug loadings of 5% and 50% w/w were used as models with the aim of studying the effects of increasing the amount of active ingredient on the dissolution performance. It was found that felodipine and copovidone in the 5% dispersion dissolve with the same dissolution rate and that no Raman spectral changes accompanied the dissolution, indicating that the two components dissolve as single entity, whose behaviour is dominated by water-soluble copovidone. For the 50% drug-loaded dispersion, partial RDDR values of both felodipine and copovidone were found to be extremely low. MCR Raman maps along with classical Raman/X-ray powder diffraction (XRPD) characterisation revealed that after an initial loss of copovidone from the extrudate the drug re-crystallises, pointing to a release dynamics dependent on the low water solubility and high hydrophobicity of felodipine. Raman imaging revealed different rates of transition from amorphous to crystalline felodipine at different locations within the dosage form

    A systematic review of the use of dosage form manipulation to obtain required doses to inform use of manipulation in paediatric practice

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    This study sought to determine whether there is an evidence base for drug manipulation to obtain the required dose, a common feature of paediatric clinical practice. A systematic review of the data sources, PubMed, EMBASE, CINAHL, IPA and the Cochrane database of systematic reviews, was used. Studies that considered the dose accuracy of manipulated medicines of any dosage form, evidence of safety or harm, bioavailability, patient experience, tolerability, contamination and comparison of methods of manipulation were included. Case studies and letters were excluded. Fifty studies were eligible for inclusion, 49 of which involved tablets being cut, split, crushed or dispersed. The remaining one study involved the manipulation of suppositories of one drug. No eligible studies concerning manipulation of oral capsules or liquids, rectal enemas, nebuliser solutions, injections or transdermal patches were identified. Twenty four of the tablet studies considered dose accuracy using weight and/or drug content. In studies that considered weight using adapted pharmacopoeial specifications, the percentage of halved tablets meeting these specifications ranged from 30% to 100%. Eighteen studies investigated bioavailability, pharmacokinetics or clinical outcomes following manipulations which included nine delayed or modified release formulations. In each of these nine studies the entirety of the dosage form was administered. Only one of the 18 studies was identified where drugs were manipulated to obtain a proportion of the dosage form, and that proportion administered. The five studies that considered patient perception found that having to manipulate the tablets did not have a negative impact on adherence. Of the 49 studies only two studies reported investigating children. This review yielded limited evidence to support manipulation of medicines for children. The results cannot be extrapolated between dosage forms, methods of manipulation or between different brands of the same drug

    Production and characterization of spray-dried theophylline powders prepared from fresh milk for potential use in paediatrics

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    "This is the accepted version of the following article: Production and characterization of spray-dried theophylline powders prepared from fresh milk for potential use in paediatrics (2017). J Pharm Pharmacol, 69: 554–566, which has been published in final form at http://dx.doi.org/10.1111/jphp.12612 . This article may be used for non-commercial purposes in accordance with the Wiley Self-Archiving Policy [http://olabout.wiley.com/WileyCDA/Section/id-820227.html]."Objective: This work evaluates the potential of using fresh milk to deliver theophylline to children.Methods: Theophylline–fresh milk systems were prepared using different solids ratios (0 : 1–1 : 0) and three fat contents in commercial milks (low, medium and high), which were spray-dried at different inlet air temperatures (Tinlet – 105, 130 and 150 °C). The process was evaluated for yield and the resulting powders for moisture content (MC), particle size and shape, density and wettability. Theophylline–milk potential interactions (differential scanning calorimetry (DSC) and FT-IR) and chemical (theophylline content) and microbiological stability of powders (shelf and in-use) were also evaluated.Key Findings: The production yield (13.6–76.0%), MC (0.0–10.3%) and contact angles in water (77.29–93.51°) were significantly (P < 0.05) affected by Tinlet, but no differences were found concerning the mean particle size (3.0–4.3 μm) of the different powders. The milk fat content significantly (P < 0.05) impacted on the density (1.244–1.552 g/cm3). Theophylline content remained stable after 6 months of storage, before extemporaneous reconstitution. After reconstitution in water, low-fat milk samples (stored at 4 °C) met the microbial pharmacopoeia criteria for up to 7 days. No theophylline–milk components interaction was observed.Conclusion: Spray-dried milk-composed powders may be used as vehicles for theophylline delivery in paediatrics following further characterization and in-vivo evaluation.info:eu-repo/semantics/publishedVersio

    Scientific Opinion on the safety and efficacy of niacin (nicotinic acid and nicotinamide) as a feed additive for all animal species based on a dossier submitted by Lonza Benelux BV

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    &lt;p&gt;The term ‘niacin’ is used as a generic description of nicotinic acid and nicotinamide with pyridine as the basic structure. Nicotinic acid and nicotinamide function mainly as precursors of the co-enzymes NAD and NADP. Thus, nicotinamide has physiologically critical roles in mitochondrial respiration and in the metabolism of carbohydrates, lipids, and amino acids. Oral administration routes of nicotinic acid and nicotinamide via feed or water for drinking were considered bioequivalent. Niacin is safe for the target animals with a margin of safety that is at least ten times the requirements and use levels. The FEEDAP Panel assumes that exposure figures for a population already include the contribution of edible tissues and products of animals fed niacin-supplemented diets. Information on niacin metabolism and the limited data available on retention in edible tissues and products indicate that supplemental levels in feeds even far higher than the requirements (1–35 mg/kg feed) are highly unlikely to lead the tolerable upper intake level being exceeded. The FEEDAP Panel considers that the use of niacin in animal nutrition is not of safety concern for consumers. Nicotinic acid and nicotinamide are not irritant to skin, but can cause irritancy to eyes and mucous membranes. They are unlikely to cause skin sensitisation. Workers might be exposed to a respirable dust when handling nicotinic acid, which should be regarded as being potentially harmful to their health. Nicotinamide is considered to be of no concern for inhalation exposure. The use of nicotinic acid and nicotinamide in animal nutrition does not pose a risk to the environment. Nicotinic acid and nicotinamide are regarded as effective sources of niacin in animal nutrition.&lt;/p&gt

    Molecular Characterisation of Long-Acting Insulin Analogues in Comparison with Human Insulin, IGF-1 and Insulin X10

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    AIMS/HYPOTHESIS: There is controversy with respect to molecular characteristics of insulin analogues. We report a series of experiments forming a comprehensive characterisation of the long acting insulin analogues, glargine and detemir, in comparison with human insulin, IGF-1, and the super-mitogenic insulin, X10. METHODS: We measured binding of ligands to membrane-bound and solubilised receptors, receptor activation and mitogenicity in a number of cell types. RESULTS: Detemir and glargine each displayed a balanced affinity for insulin receptor (IR) isoforms A and B. This was also true for X10, whereas IGF-1 had a higher affinity for IR-A than IR-B. X10 and glargine both exhibited a higher relative IGF-1R than IR binding affinity, whereas detemir displayed an IGF-1R:IR binding ratio of ≤ 1. Ligands with high relative IGF-1R affinity also had high affinity for IR/IGF-1R hybrid receptors. In general, the relative binding affinities of the analogues were reflected in their ability to phosphorylate the IR and IGF-1R. Detailed analysis revealed that X10, in contrast to the other ligands, seemed to evoke a preferential phosphorylation of juxtamembrane and kinase domain phosphorylation sites of the IR. Sustained phosphorylation was only observed from the IR after stimulation with X10, and after stimulation with IGF-1 from the IGF-1R. Both X10 and glargine showed an increased mitogenic potency compared to human insulin in cells expressing many IGF-1Rs, whereas only X10 showed increased mitogenicity in cells expressing many IRs. CONCLUSIONS: Detailed analysis of receptor binding, activation and in vitro mitogenicity indicated no molecular safety concern with detemir
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