scholarly journals Determination of Nitrate in Biological Fluids Using Nitrate Reductase in a Flow System.

2001 ◽  
Vol 47 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Hisakazu Mori
Keyword(s):  
Nitrate Reductase ◽  
Flow System ◽  
Biological Fluids

Methods for the Determination of the Purity of Exosomes

2020 ◽  
Vol 25 (42) ◽  
pp. 4464-4485 ◽  
Author(s):  
Katarzyna Kluszczyńska ◽  
Liliana Czernek ◽  
Wojciech Cypryk ◽  
Łukasz Pęczek ◽  
Markus Düchler
Keyword(s):  
Drug Transport ◽  
Biological Fluids ◽  
Drug Carriers ◽  
Biological Functions ◽  
Isolation And Purification ◽  
Pubmed Database ◽  
High Concentrations ◽  
Targeted Release

Background: Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance. Methods: Articles describing the isolation and purification of exosomes were retrieved from the PubMed database. Results: Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols. Conclusion: Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

Microextraction and Chromatographic Analysis of Budesonide Epimers in Exhaled Breath Condensate

2020 ◽  
Vol 16 (8) ◽  
pp. 1032-1040
Author(s):  
Laleh Samini ◽  
Maryam Khoubnasabjafari ◽  
Mohamad M. Alimorad ◽  
Vahid Jouyban-Gharamaleki ◽  
Hak-Kim Chan ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Exhaled Breath Condensate ◽  
Low Cost ◽  
Exhaled Breath ◽  
Chromatography Method ◽  
Extraction Solvent ◽  
Drug Concentrations ◽  
Dispersive Liquid Liquid Microextraction ◽  
Breath Condensate

Background: Analysis of drug concentrations in biological fluids is required in clinical sciences for various purposes. Among other biological samples, exhaled breath condensate (EBC) is a potential sample for follow up of drug concentrations. Methods: A dispersive liquid-liquid microextraction (DLLME) procedure followed by a validated liquid chromatography method was employed for the determination of budesonide (BDS) in EBC samples collected using a homemade setup. EBC is a non-invasive biological sample with possible applications for monitoring drug concentrations. The proposed analytical method is validated according to the FDA guidelines using EBC-spiked samples. Its applicability is tested on EBC samples collected from healthy volunteers receiving a single puff of BDS. Results: The best DLLME conditions involved the use of methanol (1 mL) as a disperser solvent, chloroform (200 μL) as an extraction solvent, and centrifugation rate of 3500 rpm for 5 minutes. The method was validated over a concentration range of 21-210 μg·L-1 in EBC. Inter- and intra-day precisions were less than 10% where the acceptable levels are less than 20%. The validated method was successfully applied for the determination of BDS in EBC samples. Conclusion: The findings of this study indicate that the developed method can be used for the extraction and quantification of BDS in EBC samples using a low cost method.

A Review of Analytical Methods for the Determination of Tibolone: Pharmacokinetics and Pharmaceutical Formulations Analysis and Application in Doping Control

2020 ◽  
Vol 17 (1) ◽  
pp. 31-39
Author(s):  
Marilene Lopes Ângelo ◽  
Fernanda de Lima Moreira ◽  
Ana Laura Araújo Santos ◽  
Hérida Regina Nunes Salgado ◽  
Magali Benjamim de Araújo
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Analytical Methods ◽  
Estrogenic Activity ◽  
Biological Fluids ◽  
Pharmaceutical Formulations ◽  
Doping Control ◽  
Specific Effects ◽  
In Doping

Background:: Tibolone is a synthetic steroid commercialized by Organon under the brand name Livial (Org OD14), which is used in hormone therapy for menopause management and treatment of postmenopausal osteoporosis. Tibolone is defined as a selective tissue estrogenic activity regulator (STEAR) demonstrating tissue-specific effects on several organs such as brain, breast, urogenital tract, endometrium, bone and cardiovascular system. Aims:: This work aims to (1) present an overview of important published literature on existing methods for the analysis of tibolone and/or its metabolites in pharmaceutical formulations and biological fluids and (2) to conduct a critical comparison of the analytical methods used in doping control, pharmacokinetics and pharmaceutical formulations analysis of tibolone and its metabolites. Results and conclusions: : The major analytical method described for the analysis of tibolone in pharmaceutical formulations is High Pressure Liquid Chromatography (HPLC) coupled with ultraviolet (UV) detection, while Liquid Chromatography (LC) or Gas Chromatography (GC) used in combination with Mass Spectrometry (MS) or tandem mass spectrometry (MS/MS) is employed for the analysis of tibolone and/or its metabolites in biological fluids.

Analytical Methods for the Determination of Sartans in Pharmaceutical Formulations and Biological Fluids: A Review

2020 ◽  
Vol 16 (3) ◽  
pp. 208-222
Author(s):  
Miglena Smerikarova ◽  
Stanislav Bozhanov ◽  
Vania Maslarska
Keyword(s):  
Biological Fluids ◽  
Pharmaceutical Preparations ◽  
Improve Patient Care ◽  
Pharmaceutical Formulations ◽  
Treatment Of Hypertension ◽  
Therapeutic Doses ◽  
Reliable Methods ◽  
Improve Patient

Background: Sartans are mostly used as a part of combination with additional medicines in the therapy of essencial hypertension. Preferred combinations are ARB and thiazide diuretics (Hydrochlorothiazide (HCT) and Chlorthalidone (CHL)) or ARB and calcium antagonists. The number of sartans mostly prescribed by specialists is only seven - Candesartan (CDS), Eprosartan (EPS), Irbesartan (IBS), Losartan (LOS), Olmesartan (OMS), Telmisartan (TMS) and Valsartan (VLS). Methods: The widespread use of sartans in the treatment of hypertension requires reliable methods of analysis. Bulk drugs and pharmaceutical preparations should be analyzed to ensure the quality of the medicinal products reaching patients. On the other hand, the analysis of drugs in biological fluids aims to trace and improve patient care by adjusting the therapeutic doses of drugs. According to our knowledge, a review devoted to the analysis of sartans was published in 2014. Results: Spectral methods are widely used in the analysis of bulk drugs and pharmaceutical dosage forms due to their relatively simple procedures, low reagent and sample consumption, speed, precision and accuracy combined with accessibility and comparatively low cost of common apparatus. Many papers for determination of sartans in bulk drugs and pharmaceutical preparations based on liquid chromatographic techniques were published in the available literature. Among these methods, HPLC takes the leading place but UPLC and HPTLC are also present. Conclusion: The widespread use of sartans in the treatment of hypertension requires reliable methods of analysis. Bulk drugs and pharmaceutical preparations should be analyzed to ensure the quality of the medicinal products reaching patients. On the other hand, the analysis of drugs in biological fluids aims to trace and improve patient care by adjusting the therapeutic doses of drugs. Since 2014, many articles have been published on the sartans analysis and this provoked our interest to summarize the latest applications in the analysis of sartans in pharmaceutical formulations and biological media. Articles published from 2014 to 2018 are covered.

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