| 1. |
- Burr, H., et al.
(författare)
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The demand–control model as a predictor of depressive symptoms—interaction and differential subscale effects : Prospective analyses of 2212 German employees
- 2021
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 18:16
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Tidskriftsartikel (refereegranskat)abstract
- Testing assumptions of the widely used demand–control (DC) model in occupational psychosocial epidemiology, we investigated (a) interaction, i.e., whether the combined effect of low job control and high psychological demands on depressive symptoms was stronger than the sum of their single effects (i.e., superadditivity) and (b) whether subscales of psychological demands and job control had similar associations with depressive symptoms. Logistic longitudinal regression analyses of the 5-year cohort of the German Study of Mental Health at Work (S-MGA) 2011/12–2017 of 2212 employees were conducted. The observed combined effect of low job control and high psychological demands on depressive symptoms did not indicate interaction (RERI = −0.26, 95% CI = −0.91; 0.40). When dichotomizing subscales at the median, differential effects of subscales were not found. When dividing subscales into categories based on value ranges, differential effects for job control subscales (namely, decision authority and skill discretion) were found (p = 0.04). This study does not support all assumptions of the DC model: (1) it corroborates previous studies not finding an interaction of psychological demands and job control; and (2) signs of differential subscale effects were found regarding job control. Too few prospective studies have been carried out regarding differential subscale effects.
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| 2. |
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| 3. |
- Hempel, Nele-Johanna, et al.
(författare)
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The Effect of the Molecular Weight of Polyvinylpyrrolidone and the Model Drug on Laser-Induced In Situ Amorphization
- 2021
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Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 26:13
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Tidskriftsartikel (refereegranskat)abstract
- Laser radiation has been shown to be a promising approach for in situ amorphization, i.e., drug amorphization inside the final dosage form. Upon exposure to laser radiation, elevated temperatures in the compacts are obtained. At temperatures above the glass transition temperature (T-g) of the polymer, the drug dissolves into the mobile polymer. Hence, the dissolution kinetics are dependent on the viscosity of the polymer, indirectly determined by the molecular weight (M-w) of the polymer, the solubility of the drug in the polymer, the particle size of the drug and the molecular size of the drug. Using compacts containing 30 wt% of the drug celecoxib (CCX), 69.25 wt% of three different M-w of polyvinylpyrrolidone (PVP: PVP12, PVP17 or PVP25), 0.25 wt% plasmonic nanoaggregates (PNs) and 0.5 wt% lubricant, the effect of the polymer M-w on the dissolution kinetics upon exposure to laser radiation was investigated. Furthermore, the effect of the model drug on the dissolution kinetics was investigated using compacts containing 30 wt% of three different drugs (CCX, indomethacin (IND) and naproxen (NAP)), 69.25 wt% PVP12, 0.25 wt% PN and 0.5 wt% lubricant. In perfect correlation to the Noyes-Whitney equation, this study showed that the use of PVP with the lowest viscosity, i.e., the lowest M-w (here PVP12), led to the fastest rate of amorphization compared to PVP17 and PVP25. Furthermore, NAP showed the fastest rate of amorphization, followed by IND and CCX in PVP12 due to its high solubility and small molecular size.
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| 4. |
- Hempel, Nele-Johanna, et al.
(författare)
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The Influence of Drug-Polymer Solubility on Laser-Induced In Situ Drug Amorphization Using Photothermal Plasmonic Nanoparticles
- 2021
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Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- In this study, laser-induced in situ amorphization (i.e., amorphization inside the final dosage form) of the model drug celecoxib (CCX) with six different polymers was investigated. The drug-polymer combinations were studied with regard to the influence of (i) the physicochemical properties of the polymer, e.g., the glass transition temperature (T-g) and (ii) the drug-polymer solubility on the rate and degree of in situ drug amorphization. Compacts were prepared containing 30 wt% CCX, 69.25 wt% polymer, 0.5 wt% lubricant, and 0.25 wt% plasmonic nanoparticles (PNs) and exposed to near-infrared laser radiation. Upon exposure to laser radiation, the PNs generated heat, which allowed drug dissolution into the polymer at temperatures above its T-g, yielding an amorphous solid dispersion. It was found that in situ drug amorphization was possible for drug-polymer combinations, where the temperature reached during exposure to laser radiation was above the onset temperature for a dissolution process of the drug into the polymer, i.e., T-DStart. The findings of this study showed that the concept of laser-induced in situ drug amorphization is applicable to a range of polymers if the drug is soluble in the polymer and temperatures during the process are above T-DStart.
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| 5. |
- Hempel, Nele-Johanna, et al.
(författare)
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Utilizing Laser Activation of Photothermal Plasmonic Nanoparticles to Induce On-Demand Drug Amorphization inside a Tablet
- 2021
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Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 18:6, s. 2254-2262
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Tidskriftsartikel (refereegranskat)abstract
- Poor aqueous drug solubility represents a major challenge in oral drug delivery. A novel approach to overcome this challenge is drug amorphization inside a tablet, that is, on-demand drug amorphization. The amorphous form is a thermodynamically instable, disordered solid-state with increased dissolution rate and solubility compared to its crystalline counterpart. During on-demand drug amorphization, the drug molecularly disperses into a polymer to form an amorphous solid at elevated temperatures inside a tablet. This study investigates, for the first time, the utilization of photothermal plasmonic nanoparticles for on-demand drug amorphization as a new pharmaceutical application. For this, near-IR photothermal plasmonic nanoparticles were tableted together with a crystalline drug (celecoxib) and a polymer (polyvinylpyrrolidone). The tablets were subjected to a near-IR laser at different intensities and durations to study the rate of drug amorphization under each condition. During laser irradiation, the plasmonic nanoparticles homogeneously heated the tablet. The temperature was directly related to the rate and degree of amorphization. Exposure times as low as 180 s at 1.12 W cm(-2) laser intensity with only 0.25 wt % plasmonic nanoparticles and up to 50 wt % drug load resulted in complete drug amorphization. Therefore, near-IR photothermal plasmonic nanoparticles are promising excipients for on-demand drug amorphization with laser irradiation.
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