| 1. |
- Brülls, Mikael, et al.
(författare)
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Applying spectral peak area analysis in near-infrared spectroscopy moisture assays
- 2007
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Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - : Elsevier BV. - 0731-7085. ; 44:1, s. 127-136
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Tidskriftsartikel (refereegranskat)abstract
- Spectral peak area analysis has in this study been shown to be a viable method in near-infrared spectroscopy (NIRS) moisture assays. The study also shows that the required number of calibration samples can be minimized, and the method is, therefore, especially suitable for moisture assays in early formulation development and in-situ process monitoring.Diffuse NIRS was utilized in the development of moisture assays for the model compounds polyvinylpyrrolidone and hydroxypropyl-beta-cyclodextrin and also for a lyophilized formulation. Reference data were obtained using coulometric Karl Fischer titration. The NIRS measurements were performed through the bottoms of the sample vials using either a Fourier Transform-Near-infrared (FT-NIR) spectrometer fitted with a diffuse reflectance probe or a dispersive single beam spectrometer. The ratios of the peak areas of a water peak at 5200 cm(-1) and a reference peak were evaluated using linear regression analysis. The spectral peak area analysis method was compared with a conventional partial least squares regression method. The moisture assays were verified using independent test sets. The investigated moisture range was 0-22% for the samples of PVP, 0-8.5% for the samples of hydroxypropyl-beta-cyclodextrin and 0.5-8.5% for the samples of the lyophilized formulation.The results of the spectral peak area analysis and the conventional partial least squares regression were similar, but the peak area method was more robust and could also make accurate predictions for lyophilized PVP samples, although the calibration set consisted of non-lyophilized samples. The peak area method required fewer calibration samples than the conventional partial least squares regression method.
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| 4. |
- Bonmann, Marlene, 1988, et al.
(författare)
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Terahertz radar observes powder dynamics for pharmaceutical manufacturing
- 2024
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Ingår i: IEEE Sensors Journal. - 1558-1748 .- 1530-437X. ; 24:13, s. 20512-20522
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Tidskriftsartikel (refereegranskat)abstract
- The optical opaqueness of powders has precluded the observation of powder flow dynamics in processing tubes, with important implications, for example, in the pharmaceutical industry, where non-destructive monitoring during the manufacturing process is essential to ensure the quality of the final product and the effectiveness of the process. Taking advantage of the high penetration of terahertz electromagnetic waves in powders and its wavelength-to-particle size ratio, we demonstrate that a submillimeter-wave pulse-Doppler radar can overcome the present challenges and characterize powder flow dynamics in pharmaceutical manufacturing processes. Mimicking typical vessel shapes in pharmaceutical operations, we were able to characterize falling powder streams in a tube with a sample volume resolution of a few cubic centimeters and a range resolution of about 5 mm. We successfully monitored particle velocity, particle distribution within the tube, and mass flow rate in real-time. This remote sensing method, based on advanced terahertz electronics, opens up the possibility to study and monitor powder dynamics in a wide range of applications.
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| 5. |
- Carlander, Christina, et al.
(författare)
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HPV Types in Cervical Precancer by HIV Status and Birth Region : A Population-Based Register Study
- 2020
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : AMER ASSOC CANCER RESEARCH. - 1055-9965 .- 1538-7755. ; 29:12, s. 2662-2668
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Tidskriftsartikel (refereegranskat)abstract
- Background: Data are lacking regarding which human papillomavirus (HPV) types cause high-grade cervical neoplasia (CIN2+) in people with HIV in Europe. We assessed which HPV types are associated with CIN2+ in women living in Sweden by HIV status.Methods: The Swedish National HIV Registry, the Swedish Population Registry, and the Swedish National Cervical Screening Registry were linked. CIN2+ tissue blocks of 130 women living with HIV (WLWH) and 234 HIV-negative women, matched for country of birth (1:2), were retrieved from bio-banks and HPV genotyped. Adjusted ORs (adjOR), stratified by country of birth, were calculated using conditional logistic regression. Matching was broken for cross-group comparisons.Results: WLWH with CIN2 were less likely to have HPV16 [14% vs. 40%; adjOR 0.1; 95% confidence interval (CI), 0.04-0.56] than HIV-negative women, but among women with CIN3, there was no difference in HPV16 prevalence by HIV status (adjOR 0.9; 95% CI, 0.51-1.70). WLWH were six times more likely to have HPV35 in CIN3 than HIV-negative women (adjOR 6.2; 95% CI, 1.3-30.4). WLWH from sub-Saharan Africa (SSA) had less 9-valent vaccine types, compared with both HIV-negative women born in Sweden (adjOR 0.1; 95% CI, 0.02-0.44) and WLWH born in Sweden (adjOR 0.1; 95% CI, 0.01-0.73), mostly because of decreased HPV16 and increased HPV35.Conclusions: WLWH from SSA were less likely to be covered by the 9-valent vaccine, mostly due to less HPV16 and more HPV35. Impact: This could have implications for HPV vaccines, currently not including HPV35, and for HPV-screening algorithms in women with origin from SSA.
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| 6. |
- Carlander, Christina, et al.
(författare)
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Suppressive antiretroviral therapy associates with effective treatment of high-grade cervical intraepithelial neoplasia
- 2018
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Ingår i: AIDS. - : LIPPINCOTT WILLIAMS & WILKINS. - 0269-9370 .- 1473-5571. ; 32:11, s. 1475-1484
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To assess if women living with HIV (WLWH) have poorer outcome after treatment of cervical intraepithelial neoplasia grade 2, grade 3, adenocarcinoma in situ or cervical cancer (CIN2+) than HIV-negative women (HNW) and to identify predictors of CIN2+ treatment failure and recurrence in WLWH. Design: Population-based cohort study with follow-up between 1983 and 2015. Methods: The Swedish National HIV Registry, the Swedish Population Registry and the Swedish National Cervical Screening Registry were linked to identify all women in Stockholm and Gothenburg counties (Sweden) living with HIV and diagnosed with CIN2+ (n = 179) sometime between 1983 and 2014. For each WLWH, two HNW resident in the same counties and matched for country of birth, diagnosed with CIN2+, were chosen as controls. Treatment failure was defined as the presence of CIN2+ at initial follow-up. Recurrence was defined as the presence of CIN1+ subsequent to an initial normal follow-up. Results: WLWH were three times more likely to have treatment failure (odds ratio (OR) 3.7 [95% confidence interval (CI) 2.0-6.8]) and five times more likely to recur (hazard ratio 5.0 [95% CI 2.1-11.6]) than HNW. Suppressive antiretroviral therapy (ART) at time of treatment of CIN2+ was associated with reduced OR of treatment failure (OR 0.3 [95% CI 0.1-0.8]). Immunosuppression (CD4(+) cell count < 200 cells/mu l) associated strongly with treatment failure (OR compared with CD4 (+) cell count >= 500: 8.5 [95% CI 2.3-30.7]). Conclusion: Suppressive ART is associated with effective treatment of CIN2+. Early HIV diagnosis and ART are essential for successful CIN2+ treatment.
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| 7. |
- Dumarey, Melanie, 1982-, et al.
(författare)
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Combining experimental design and orthogonal projections to latent structures to study the influence of microcrystalline cellulose properties on roll compaction
- 2011
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Ingår i: International Journal of Pharmaceutics. - : Elsevier. - 0378-5173 .- 1873-3476. ; 416:1, s. 110-119
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Tidskriftsartikel (refereegranskat)abstract
- Roll compaction is gaining importance in pharmaceutical industry for the dry granulation of heat or moisture sensitive powder blends with poor flowing properties prior to tabletting. We studied the influence of microcrystalline cellulose (MCC) properties on the roll compaction process and the consecutive steps in tablet manufacturing. Four dissimilar MCC grades, selected by subjecting their physical characteristics to principal components analysis, and three speed ratios, i.e. the ratio of the feed screw speed and the roll speed of the roll compactor, were included in a full factorial design. Orthogonal projection to latent structures was then used to model the properties of the resulting roll compacted products (ribbons, granules and tablets) as a function of the physical MCC properties and the speed ratio. This modified version of partial least squares regression separates variation in the design correlated to the considered response from the variation orthogonal to that response. The contributions of the MCC properties and the speed ratio to the predictive and orthogonal components of the models were used to evaluate the effect of the design variation. The models indicated that several MCC properties, e.g. bulk density and compressibility, affected all granule and tablet properties, but only one studied ribbon property: porosity. After roll compaction, Ceolus KG 1000 resulted in tablets with obvious higher tensile strength and lower disintegration time compared to the other MCC grades. This study confirmed that the particle size increase caused by roll compaction is highly responsible for the tensile strength decrease of the tablets.
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| 10. |
- Kamran, Faisal, et al.
(författare)
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Transmission Near-Infrared (NIR) and Photon Time-of-Flight (PTOF) Spectroscopy in a Comparative Analysis of Pharmaceuticals
- 2015
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Ingår i: Applied Spectroscopy. - : SAGE Publications. - 1943-3530 .- 0003-7028. ; 69:3, s. 389-397
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive study of the application of photon time-of-flight spectroscopy (PTOFS) in the wavelength range 1050 1350 nm as a spectroscopic technique for the evaluation of the chemical composition and structural properties of pharmaceutical tablets. PTOFS is compared to transmission near-infrared spectroscopy (NIRS). In contrast to transmission NIRS, PTOFS is capable of directly and independently determining the absorption and reduced scattering coefficients of the medium. Chemometric models were built on the evaluated absorption spectra for predicting tablet drug concentration. Results are compared to corresponding predictions built on transmission NIRS measurements. The predictive ability of PTOFS and transmission NIRS is comparable when models are based on uniformly distributed tablet sets. For non-uniform distribution of tablets based on particle sizes, the prediction ability of PTOFS is better than that of transmission NIRS. Analysis of reduced scattering spectra shows that PTOFS is able to characterize tablet microstructure and manufacturing process parameters. In contrast to the chemometric pseudovariables provided by transmission NIRS, PTOFS provides physically meaningful quantities such as scattering strength and slope of particle size. The ability of PTOFS to quantify the reduced scattering spectra, together with its robustness in predicting drug content, makes it suitable for such evaluations in the pharmaceutical industry.
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