181 research outputs found
Fused deposition modeling 3D printing as a method for manufacturing personalized medicines
Additive manufacturing techniques, especially methods based on the deposition of thermoplastic material such as Fused deposition modeling (FDM), are gaining more and more applications. Due to the large variety of materials used and the quick ability to produce small batches of products in accordance with the computer project, these methods are considered as a method of dosage forms manufacturing both on an industrial scale as well as in small batches.
Numerous scientific studies related to the printing of dosage forms of various structures have been published in recent years. These studies concern both preparations for oral administration, such as tablets and capsules with modified and immediate release of the active pharmaceutical ingredient (API), as well as intraocular dosage forms and wound dressings.
In the case of the FDM method, the printing process is preceded by the material preparation step. It consists of the preparation of a drug-loaded filament in the hot-melt extrusion process. After feeding the filament into the printer's head, it is re-heated, liquefied, and precisely deposited on the printer's table in order to reproduce a spatial structure according to the computer design.
The filaments used in the printing process of the dosage form should be characterized by, among others: appropriate mechanical strength, high diameter uniformity, and long-term stability. Apart from thermoplastic polymers, other excipients are also used in the composition of the formulation, i.e., disintegrants, plasticizers, and compounds inhibiting the API phase transformations in the polymer matrix.
Printed dosage forms are often characterized by a complex internal spatial structure. For this reason, the API release depends not only on the properties of the excipients used, but especially on printouts’ surface area and porosity, as well as the shape and infill density. In addition, conditions during the extrusion and 3D printing processes may result in the dissolution of API in the polymer carrier and accelerate its dissolution rate
Compensatory Puffing With Lower Nicotine Concentration E-liquids Increases Carbonyl Exposure in E-cigarette Aerosols
Introduction: Article 20 of the European Tobacco Products Directive (EU-TPD) specifies that
e-liquids should not contain nicotine in excess of 20 mg/mL, thus many vapers may be compelled
to switch to lower concentrations and in so doing, may engage in more intensive puffing. This
study aimed to establish whether more intensive puffing produces higher levels of carbonyl compounds
in e-cigarette aerosols.
Methods: Using the HPLC-UV diode array method, four carbonyl compounds (formaldehyde, acetaldehyde,
acetone, and acrolein) were measured in liquids and aerosols from nicotine solutions of
24 and 6 mg/mL. Aerosols were generated using a smoking machine configured to replicate puffing
topography data previously obtained from 12 experienced e-cigarette users.
Results: Carbonyl levels in aerosols from the puffing regimen of 6 mg/mL were significantly higher
(p < .05 using independent samples t tests) compared with those of 24 mg/mL nicotine. For the 6 and
24 mg/mL nicotine aerosols respectively, means ± SD for formaldehyde levels were 3.41 ± 0.94, and 1.49 ±
0.30 μg per hour (μg/h) of e-cigarette use. Means ± SD for acetaldehyde levels were 2.17 ± 0.36 and 1.04 ±
0.13 μg/h. Means ± SD for acetone levels were 0.73 ± 0.20 and 0.28 ± 0.14 μg/h. Acrolein was not detected.
Conclusions: Higher levels of carbonyls associated with more intensive puffing suggest that vapers
switching to lower nicotine concentrations (either due to the EU-TPD implementation or personal
choice), may increase their exposure to these compounds. Based on real human puffing topography
data, this study suggests that limiting nicotine concentrations to 20 mg/mL may not result in
the desired harm minimalization effect.
Implications: More intensive puffing regimens associated with the use of low nicotine concentration
e-liquids can lead to higher levels of carbonyl generation in the aerosol. Although in need of replication
in a larger sample outside a laboratory, this study provides pragmatic empirical data on the potential
risks of compensatory puffing behaviors in vapers, and can help to inform future regulatory decisions
on nicotine e-liquid concentrations. The cap on nicotine concentration at 20 mg/mL set by the EU-TPD
may therefore have the unintended consequence of encouraging use of lower nicotine concentration
e-liquid, in turn increasing exposure to carbonyl compounds through compensatory puffing
Multivariate design of 3D printed immediate-release tablets with liquid crystal-forming drug - itraconazole
The simplicity of object shape and composition modification make additive manufacturing
a great option for customized dosage form production. To achieve this goal, the correlation between
structural and functional attributes of the printed objects needs to be analyzed. So far, it has not
been deeply investigated in 3D printing-related papers. The aim of our study was to modify the
functionalities of printed tablets containing liquid crystal-forming drug itraconazole by introducing
polyvinylpyrrolidone-based polymers into the filament-forming matrices composed predominantly
of poly(vinyl alcohol). The e ect of the molecular reorganization of the drug and improved tablets’
disintegration was analyzed in terms of itraconazole dissolution. Micro-computed tomography was
applied to analyze how the design of a printed object (in this case, a degree of an infill) a ects its
reproducibility during printing. It was also used to analyze the structure of the printed dosage forms.
The results indicated that the improved disintegration obtained due to the use of Kollidon®CL-M
was more beneficial for the dissolution of itraconazole than the molecular rearrangement and liquid
crystal phase transitions. The lower infill density favored faster dissolution of the drug from printed
tablets. However, it negatively a ected the reproducibility of the 3D printed object
How to obtain the maximum properties flexibility of 3d printed ketoprofen tablets using only one drug-loaded filament?
The flexibility of dose and dosage forms makes 3D printing a very interesting tool for personalized medicine, with fused deposition modeling being the most promising and intensively developed method. In our research, we analyzed how various types of disintegrants and drug loading in poly(vinyl alcohol)-based filaments affect their mechanical properties and printability. We also assessed the effect of drug dosage and tablet spatial structure on the dissolution profiles. Given that the development of a method that allows the production of dosage forms with different properties from a single drug-loaded filament is desirable, we developed a method of printing ketoprofen tablets with different dose and dissolution profiles from a single feedstock filament. We
optimized the filament preparation by hot-melt extrusion and characterized them. Then, we printed single, bi-, and tri-layer tablets varying with dose, infill density, internal structure, and composition. We analyzed the reproducibility of a spatial structure, phase, and degree of molecular order of ketoprofen in the tablets, and the dissolution profiles. We have printed tablets with immediateand sustained-release characteristics using one drug-loaded filament, which demonstrates that a single filament can serve as a versatile source for the manufacturing of tablets exhibiting various release characteristics
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state
A search for the rare decays and is performed in a data set corresponding to an integrated luminosity of 3.0 fb collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with muon pairs that do not originate from a resonance are considered. The first observation of the decay and the first evidence of the decay are obtained and the branching fractions are measured to be and , where the third uncertainty is due to the branching fraction of the decay , used as a normalisation.A search for the rare decays Bs0→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−μ+μ−)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8 , where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K⁎(892)0(→K+π−) , used as a normalisation.A search for the rare decays Bs0→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−μ+μ−)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8 , where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K⁎(892)0(→K+π−) , used as a normalisation.A search for the rare decays and is performed in a data set corresponding to an integrated luminosity of 3.0 fb collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with muon pairs that do not originate from a resonance are considered. The first observation of the decay and the first evidence of the decay are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be and , where the third uncertainty is due to the branching fraction of the decay , used as a normalisation
Angular analysis of the B-0 -> K*(0) e(+) e(-) decay in the low-q(2) region
An angular analysis of the decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared () interval between 0.002 and 1.120. The angular observables and which are related to the polarisation and to the lepton forward-backward asymmetry, are measured to be and , where the first uncertainty is statistical and the second systematic. The angular observables and which are sensitive to the photon polarisation in this range, are found to be and . The results are consistent with Standard Model predictions.An angular analysis of the B → K^{*}^{0} e e decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q) interval between 0.002 and 1.120 GeV /c. The angular observables F and A which are related to the K^{*}^{0} polarisation and to the lepton forward-backward asymmetry, are measured to be F = 0.16 ± 0.06 ± 0.03 and A = 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables A and A which are sensitive to the photon polarisation in this q range, are found to be A = − 0.23 ± 0.23 ± 0.05 and A = 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.An angular analysis of the decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared () interval between 0.002 and 1.120. The angular observables and which are related to the polarisation and to the lepton forward-backward asymmetry, are measured to be and , where the first uncertainty is statistical and the second systematic. The angular observables and which are sensitive to the photon polarisation in this range, are found to be and . The results are consistent with Standard Model predictions
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