〈1467〉 Residual Solvents—Verification of Compendial Procedures and Validation of Alternative Procedures

2018 ◽  
Vol 12 (02) ◽  
pp. 155-165
Author(s):  
Holger Hendrix ◽  
Vladimir Kamlak ◽  
Georgi Prisadov ◽  
Katrin Welcker

The treatment of pain after thoracic surgery is a challenge and takes place in the individual clinics mostly according to clinic internal standards. It exists no currently valid S3 guideline for the treatment of acute perioperative and posttraumatic pain. For an effective pain treatment as well individual pain experience as the pain intensity of the various thoracic surgical procedures must be considered. Regular pain assessment with appropriate methods and their documentation form the basis for adequate and adapted pain therapy.There are a number of different pain therapy methods, non-medicamentous and drug-based methods, whose effectiveness is described in the literature partially different. For the treatment of acute postoperative pain after thoracic surgery, mainly drug-related procedures are used, except for physiotherapy as a non-medicamentous method. Increasingly, alternative procedures for the peridural catheter as a therapeutic gold standard in the treatment of pain after thoracic surgery are used. Their application can be integrated into a therapeutic algorithm.


2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.


1979 ◽  
Vol 62 (1) ◽  
pp. 153-159
Author(s):  
Luis F Corominas ◽  
Victor M Boy ◽  
Manuel Guijosa

Abstract The official first action AOAC method for the spectrophotometric determination of biuret in urea, 2.072—2.074, was compared with official first action AOAC method 2.C01-2.C03 (atomic absorption spectrophotometry), 2 simplified versions of 2.072-2.074, and modified versions of 2 alternative procedures of the International Organization for Standardization. Three synthetic urea samples (0.3, 1.4, and 3.0% biuret) and 1 commercial urea sample (1.0% biuret) were analyzed. The methods proved to be equivalent and none showed a definite advantage over 2.072-2.074. The purification of biuret and the interference by ammonia are also discussed.


2002 ◽  
Vol 12 (2) ◽  
pp. 81-87 ◽  
Author(s):  
Christophe Baravian ◽  
Audrey Lalante ◽  
Alan Parker

Abstract The vane geometry with a large gap is used to determine the Newtonian, non-Newtonian and viscoelastic properties of complex fluids. We show that when this geometry is carefully characterized, it can be used for precise rheometry. A novel effective cylinder approximation is used to obtain the shear rate and shear stress factors. The effective radius is found to be close to the height of the triangle formed by joining the tips of adjacent blades. This result differs significantly from that of previous work. Flow visualization has been used to confirm that the stream lines bend towards the centre between the blades. These factors can be used to determine the flow curves of non-Newtonian liquids, using Krieger’s power law expansion. The standard procedure for using the vane to determine the yield stress is also carefully investigated and alternative procedures are suggested.


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