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Journal of AOAC International Jun 2021Losartan potassium, a common antihypertensive drug on the market, has multiple polymorphs, of which form I is used as a pharmaceutical crystal form. Form I can be...
BACKGROUND
Losartan potassium, a common antihypertensive drug on the market, has multiple polymorphs, of which form I is used as a pharmaceutical crystal form. Form I can be partially converted to form III under some circumstances. The quantification of losartan potassium polymorphs is important to control the quality of pharmaceuticals.
OBJECTIVE
To establish a method to determine the contents of losartan potassium polymorphs.
METHODS
Pure form I and form III of losartan potassium were obtained by recrystallization, and characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy, Raman spectroscopy, and thermal analysis. A powder X-ray diffraction method was developed to characterize form I and form III of losartan potassium. Peak area and weight percentage were used to establish calibration curve.
RESULTS
The calibration curve was linear over the range of 1-50% (w/w), using the characteristic peak area ratio of form I at 11.13° 2θ and form III at 5.64° 2θ as the quantitative parameter. The precisions were excellent between 0.6-4.9%, and the limit of quantification was 2.02% (w/w).
CONCLUSIONS
This PXRD method can be used to analyze mixtures of losartan potassium polymorphs (forms I and III) quantitatively and control the quality of bulk drug.
HIGHLIGHTS
This is a new method of quantifying the amount of form III in polymorphic forms of losartan potassium using data obtained by PXRD. It is consistent, sensitive, and accurate.
Topics: Calorimetry, Differential Scanning; Losartan; Powder Diffraction; Powders; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction
PubMed: 33337486
DOI: 10.1093/jaoacint/qsaa166 -
Talanta Apr 2019A considerable number of fatal intoxications have recently been connected with the growing popularity of new psychoactive substances (NPS). Therefore, there is a...
A considerable number of fatal intoxications have recently been connected with the growing popularity of new psychoactive substances (NPS). Therefore, there is a significant demand for the development of fast and facile field detection methods for NPS. These substances are often sold as blends (with inorganic or organic cutting agents), which may further complicate detection. X-Ray powder diffraction (XRPD) was evaluated as a suitable and easily employable analytical method for the identification of NPS. XRPD has been successfully used for the differentiation of eight synthetic cathinones with a similar molecular structure. Moreover, this method was also used for the identification of four drugs in authentic street samples. XRPD is a facile non-destructive method that can identify not only NPS in mixtures but also the cutting agents. The small amount of substances needed for the measurement, which can be re-used for other analyses, further enhances the versatility of this method.
Topics: Alkaloids; Central Nervous System Stimulants; Powder Diffraction; Psychotropic Drugs; X-Ray Diffraction
PubMed: 30625563
DOI: 10.1016/j.talanta.2018.11.063 -
Acta Crystallographica. Section A,... Sep 2022A prototype application for machine-readable literature is investigated. The program is called pyDataRecognition and serves as an example of a data-driven literature...
A prototype application for machine-readable literature is investigated. The program is called pyDataRecognition and serves as an example of a data-driven literature search, where the literature search query is an experimental data set provided by the user. The user uploads a powder pattern together with the radiation wavelength. The program compares the user data to a database of existing powder patterns associated with published papers and produces a rank ordered according to their similarity score. The program returns the digital object identifier and full reference of top-ranked papers together with a stack plot of the user data alongside the top-five database entries. The paper describes the approach and explores successes and challenges.
Topics: Databases, Factual; Powder Diffraction; Powders; Publications
PubMed: 36047395
DOI: 10.1107/S2053273322007483 -
Journal of Pharmaceutical Sciences Oct 2022The widespread use of amorphous solid dispersions (ASDs) dictates that analytical methods are required to accurately quantify crystallinity and characterize crystals...
Comparison of Differential Scanning Calorimetry, Powder X-ray Diffraction, and Solid-state Nuclear Magnetic Resonance Spectroscopy for Measuring Crystallinity in Amorphous Solid Dispersions - Application to Drug-in-polymer Solubility.
The widespread use of amorphous solid dispersions (ASDs) dictates that analytical methods are required to accurately quantify crystallinity and characterize crystals formed in order to help design a stable ASD. Current crystallinity quantitation methods are limited to ASDs of moderate drug loadings, single polymorphs, and fast crystallization kinetics. The ability of multiple differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and solid-state nuclear magnetic resonance (SSNMR) techniques were compared for quantifying crystallinity in ASDs in varying conditions. Determining crystallinity by DSC is limited by its ability to measure T or heat of fusion. PXRD was relatively robust in determining crystalline and amorphous ratios for drug-polymer systems in the absence of other excipients. SSNMR provides both quantitative information and reveal how crystal quality changes with crystallization conditions and helps to explain the failure of DSC methods. The results of five different methods using three techniques were directly applied to measure drug-in-polymer solubility with four agreeing well with the literature. PXRD and SSNMR are therefore proposed as alternative methods to quantify crystallinity and predict drug-in-polymer solubility when DSC methods do not work. In-situ and ex-situ annealing was also compared, and equivalent crystallinity data was acquired.
Topics: Calorimetry, Differential Scanning; Excipients; Magnetic Resonance Spectroscopy; Polymers; Powder Diffraction; Powders; Solubility; X-Ray Diffraction
PubMed: 35421430
DOI: 10.1016/j.xphs.2022.04.004 -
Analytical Sciences : the International... Dec 2022The thermal behavior of stellerite from the Savinskoye deposit (Transbaikalia, Russia), CaNaK(SiAl)O·53.39HO, was investigated by in situ high-temperature X-ray powder...
The thermal behavior of stellerite from the Savinskoye deposit (Transbaikalia, Russia), CaNaK(SiAl)O·53.39HO, was investigated by in situ high-temperature X-ray powder diffraction (HTXRPD) and ex situ HT infrared (IR) spectroscopic analysis. Four different HTXRPD experimental procedures were used to study the thermal behavior of the powder samples: (1) RT-750 °C, (2) RT-220 °C -RT, (3) 200-350-RT °C, and (4) 350-700 °C. Electron probe microanalysis and single-crystal X-ray diffraction were preliminary used to determine the chemical composition and crystal structure of stellerite. The A → B phase transition (Fmmm → Amma) starts at ∼110 °C and is completed at about 140 °C (in situ HTXRPD) and 200 °C (ex situ HTIR) depending on the experimental conditions. It involves a cell volume decrease of 5.8% (Experiment 1). The thermal expansion of stellerite is more pronounced along the b and c axes, with αa: αb: αc (× 10) = 2.50:-25.52:-6.84 at 100 °C, 0.44:-21.75:-25.64 at 150 °C after the completion of the phase transition, and 3.06:-1.86:-16.94 at 500 °C. The reverse B → A transition occurs at temperatures below 100 °C during slow cooling (Experiment 2), however, it does not occur upon rapid cooling (Experiment 3). The B → D phase transition above 300 °C is not observed (Experiment 4). The temperature barrier of phase transition in the ex situ HTIR spectroscopy experiment is shifted towards high temperatures. The heating above 200 °C leads to an increase of 3430 cm and a decrease of 3600 and 3260 cm bands, which correspond to the stretching vibration of HO. The heating above 400 °C causes complete dehydration of the stellerite.
Topics: X-Ray Diffraction; Temperature; Powders; Powder Diffraction; X-Rays
PubMed: 36094727
DOI: 10.1007/s44211-022-00186-4 -
Acta Crystallographica Section B,... Apr 2022Schmidt and co-workers [ (2022), B, 195–213], report a strategy for structure determination from powder XRD data in which unit-cell determination and structure...
Schmidt and co-workers [ (2022), B, 195–213], report a strategy for structure determination from powder XRD data in which unit-cell determination and structure solution are combined within a single process, rather than handling them as sequential stages on the structure determination pathway. This strategy offers the prospect to achieve successful structure determination in cases for which conventional approaches for indexing powder XRD data prove to be challenging.
Topics: Crystallography, X-Ray; Molecular Structure; Powder Diffraction
PubMed: 35411848
DOI: 10.1107/S2052520622003717 -
Acta Crystallographica. Section A,... Jan 2008Following the seminal work of Von Dreele, powder X-ray diffraction studies on proteins are being established as a valuable complementary technique to single-crystal...
Following the seminal work of Von Dreele, powder X-ray diffraction studies on proteins are being established as a valuable complementary technique to single-crystal measurements. A wide range of small proteins have been found to give synchrotron powder diffraction profiles where the peak widths are essentially limited only by the instrumental resolution. The rich information contained in these profiles, combined with developments in data analysis, has stimulated research and development to apply the powder technique to microcrystalline protein samples. In the present work, progress in using powder diffraction for macromolecular crystallography is reported.
Topics: Animals; Chickens; Crystallography, X-Ray; Egg White; Insulin; Metmyoglobin; Models, Molecular; Muramidase; Powder Diffraction; Proteins; Purple Membrane
PubMed: 18156682
DOI: 10.1107/S0108767307043735 -
Analytical Chemistry Nov 2015Here we demonstrate the use of second harmonic generation (SHG) microscopy-guided synchrotron powder X-ray diffraction (PXRD) for the detection of trace crystalline...
Here we demonstrate the use of second harmonic generation (SHG) microscopy-guided synchrotron powder X-ray diffraction (PXRD) for the detection of trace crystalline active pharmaceutical ingredients in a common polymer blend. The combined instrument is capable of detecting 100 ppm crystalline ritonavir in an amorphous hydroxypropyl methylcellulose matrix with a high signal-to-noise ratio (>5000). The high spatial resolution afforded by SHG microscopy allows for the use of a minibeam collimator to reduce the total volume of material probed by synchrotron PXRD. The reduction in probed volume results in reduced background from amorphous material. The ability to detect low crystalline loading has the potential to improve measurements in the formulation pipeline for pharmaceutical solid dispersions, for which even trace quantities of crystalline active ingredients can negatively impact the stability and bioavailability of the final drug product.
Topics: Limit of Detection; Powder Diffraction
PubMed: 26465382
DOI: 10.1021/acs.analchem.5b02758 -
Biopolymers Feb 2015One-dimensional (1D) (spherically averaged) powder diffraction diagrams are commonly used to determine the degree of cellulose crystallinity in biomass samples. Here, it...
One-dimensional (1D) (spherically averaged) powder diffraction diagrams are commonly used to determine the degree of cellulose crystallinity in biomass samples. Here, it is shown using molecular modeling how disorder in cellulose fibrils can lead to considerable uncertainty in conclusions drawn concerning crystallinity based on 1D powder diffraction data alone. For example, cellulose microfibrils that contain both crystalline and noncrystalline segments can lead to powder diffraction diagrams lacking identifiable peaks, while microfibrils without any crystalline segments can lead to such peaks. This leads to false positives, that is, assigning disordered cellulose as crystalline, and false negatives, that is, categorizing fibrils with crystalline segments as amorphous. The reliable determination of the fraction of crystallinity in any given biomass sample will require a more sophisticated approach combining detailed experiment and simulation.
Topics: Cellulose; Crystallography, X-Ray; Powder Diffraction; X-Ray Diffraction
PubMed: 25269646
DOI: 10.1002/bip.22555 -
European Journal of Pharmaceutical... Apr 2021Direct derivation (DD) is a novel Powder X-ray diffraction quantification method based on intensity-composition equation, which can determine the weight fraction of...
Direct derivation (DD) is a novel Powder X-ray diffraction quantification method based on intensity-composition equation, which can determine the weight fraction of individual phases in a mixture of components by chemical formulas . The DD method was applied to determine crystallinity degree of binary mixtures containing amorphous hydroxypropyl methylcellulose and crystalline monohydrate α-lactose in weight percentage ≤ 15% w/w. Three different scenarios were considered: a) the unit cell parameters of the crystalline phases are available b) the unit cell parameters are unknown but the patterns of pure crystalline and amorphous references are available and c) only the mixtures' patterns are available. Relative errors in scenarios a and b were comparable and reasonable (<20%), while in c, the crystalline degree was clearly underestimated evidencing the importance of determining the maximum number of crystalline reflections This can be easily achieved when the unit cell parameters and/or the patterns of pure references are available. To simulate the quantification of high potent API, the method was evaluated considering the scenario b, in samples covered by Kapton® film as containment system. In this case, an accurate quantification was achieved by subtracting the film signal from the observed pattern.
Topics: Powder Diffraction; Powders; X-Ray Diffraction; X-Rays
PubMed: 33373746
DOI: 10.1016/j.ejps.2020.105692