scholarly journals STRESS DEGRADATION OF LISINOPRIL DIHYDRATE IN DIFFERENT AQUEOUS MEDIA

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Irena Kasagić Vujanović ◽  
Darija Knežević ◽  
Nina Vukičević
Keyword(s):  
Ace Inhibitor ◽  
Degradation Products ◽  
Aqueous Media ◽  
Increased Risk ◽  
Constant Rate ◽  
Main Degradation Product ◽  
Stress Degradation ◽  
The Stability ◽  
Definition Of ◽  
Kinetics And Activation Energy

Lisinopril is an antihypertensive drug from the ACE inhibitor group. It is often used in practice and, in oral administration is characterized by very low percentage of resorption (~25%). Therefore, it is important to ensure the stability of this drug, since any degradation leads to a decrease in the percentage of resorption and an increased risk of sub-dosage of patients. In accordance with modern trends of pharmaceutical analysis, the chemical stability of lisinopril under the influence of various aqueous media was tested: distilled water, 0.1M HCl, 0.1M and 0.01M NaOH and 3% hydrogen peroxide solution. In order to clearly define the effect of elevated temperature on the stability of this drug, tests were carried out at 25 °C and 50 °C. High-pressure liquid chromatography was used as the method for stability testing. The obtained results clearly define that lisinopril is the most sensitive to hydrolysis in the base environment, where at 25 °C, in the first minute, it degrades ~100%. In this paper, kinetic parameters (degradation constant rate, half-life of degradation, order kinetics, and activation energy) were also determined, which enabled clear definition of the stability and identification of degradation products of lisinopril under the influence of various stress agents. In the degradation of lisinopril in neutral and acidic medium, impurity D is identified as the main degradation product.

scholarly journals Degradation Studies of Lacidipine: Identification, Isolation and Structural Characterization of Stress Degradation Products using LCMS, Mass mediated Prep-HPLC, NMR and HRMS

2021 ◽  
Vol 33 (6) ◽  
pp. 1341-1350
Author(s):  
K.V.K. Mohan Pulletikurthi ◽  
S.S.K. Chakravarthy Kotha ◽  
Raju Doddipalla ◽  
Chidananda Swamy Rumalla ◽  
Muralidharan Kaliyaperumal ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Degradation Products ◽  
Gradient Elution ◽  
Stress Conditions ◽  
Drug Degradation ◽  
Ich Guidelines ◽  
Oxidative Condition ◽  
Stress Degradation ◽  
The Stability

The stability of lacidipine drug under stress conditions and the identification of the degradation products, according to ICH guidelines Q1A (R2) were investigated in the hydrolytic and oxidative stress conditions. The drug degradation occurred under hydrolytic conditions like (acidic and basic) while it was stable in the oxidative condition. Three degradation products were formed under acidic condition and one degradation product was formed under basic condition, which was separated by using APMS (Auto Purification Mass Spectrometer) and gradient elution with C18 column. The four degradants have not been characterized earlier and in the present study all the structures were established and characterized using NMR spectroscopy (1D and 2D) and HRMS (high resolution mass spectrometer).

scholarly journals Fasten, simple, and specific stability of the avant-garde RP-HPLC method for estimation and validation of nystatin in pharmaceutical formulations

2019 ◽  
Vol 10 (4) ◽  
pp. 3717-3727
Author(s):  
Dawood CH. Al-Bahadily ◽  
Rasool Chaloob ◽  
Kulood H. Oudah ◽  
H. N. K. AL-Salman ◽  
Falah Hassan Shari ◽  
...  
Keyword(s):  
Flow Rate ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Pharmaceutical Formulations ◽  
Hplc Method ◽  
Avant Garde ◽  
Rp Hplc ◽  
Specificity And Sensitivity ◽  
Stress Degradation ◽  
The Stability

In this study, a simple and reliable stability-indicating RP-HPLC method was developed and validated for the analysis of Nystatin in the pharmaceuticals. The chromatographic separation was performed in the isocratic mode on an Ion Pac column; Arcus EP‑C18; 5μm, 4.6×250 mm, 30 °C) using a mobile phase consisting of ammonium acetate 0.05 M buffer/ Methanol mixture (30:70) and a flow-rate of 1.0 mL/min with UV detection at 305 nm. The flow rate was set at 1.0 mL/min. The HPLC analysis method was validated in terms of linearity, precision, accuracy, specificity, and sensitivity, according to International Conference on Harmonization (ICH) guidelines. The results indicated that the retention time was 8 min, and no interferences were observed from the formulation excipients and stress degradation products.  The specificity, linearity, precision, accuracy, LOD, and LOQ of the method were validated. The method was linear over the range of 5–500 μg/mL with an acceptable correlation coefficient (R2 = 0.9996). The method’s limit of detection (LOD) and quantification (LOQ) were 0.01 and 0.025 μg/mL, respectively. The results indicate that this validated method can be used as an alternative method for the assay of nystatin. This validated HPLC method could be used for routine analysis, quality control, and the stability of analysis of Nystatin formulations.

scholarly journals IMPURITY PROFILING OF FIRST LINE ANTI-TB DRUG-TERIZIDONE USING CHROMATOGRAPHIC AND RELATED TECHNIQUES

2021 ◽  
pp. 83-95
Author(s):  
PRAGATI J. VANAVI ◽  
SADHANA J. RAJPUT
Keyword(s):  
Formic Acid ◽  
Degradation Products ◽  
Storage Condition ◽  
Stability Study ◽  
Preparative Hplc ◽  
Esi Ms ◽  
Impurity Profiling ◽  
Stress Degradation ◽  
Bulk Drug ◽  
The Stability

Objective: The objective of the present study was to investigate the stability of TRZ against different stressors and to prepare impurity profile for potential impurities and degradation products (DPs) formed under stress degradation of TRZ bulk drug and formulation. Methods: Three analytical methods were developed; the stability-indicating method that was developed using HPLC instrument with 0.01M ammonium acetate buffer (pH 4.0 using glacial acetic acid (GAA)) and acetonitrile in gradient program. The second method was a UPLC/ESI-MS method using 0.1 % Formic acid in Milli Q water (pH= 2.70) and 0.1%Formic acid in Milli Q water: Acetonitrile (10:90) in gradient program for identification of TRZ and DPs while the third, preparative HPLC method was used for isolation of impurities using (A) 0.05% ammonia (NH3) in water and (B) Acetonitrile+20% mobile phase A in gradient sequence. Gradient sequences are described in the main text. Results: The analytical method for stability study was developed and validated using ICH (Q2) R1 guidelines. The result of stability study by stress degradation showed that TRZ was susceptible to degradation in acid (7 DPs), alkaline, neutral (9 DPs) and oxidative conditions (10 DPs); major DPs were identified (where it was possible) and the chemical structure was elucidated by combining the data of ESI/MS, NMR and/or Tandem MS. The Impurity profiling was completed by reporting all the DPs, either major or minor for TRZ bulk drug and formulation. Conclusion: The complete Impurity profiling for TRZ is reported for the first time in literature. The study data would be add-on for formulation storage condition and further development.

Development and Validation of a Stability Indicating LC-MS/MS Method for the Determination of Clenbuterol HCl

Drug Research ◽  
2020 ◽  
Vol 70 (12) ◽  
pp. 552-562
Author(s):  
Krunal J. Prajapati ◽  
Charmy Kothari
Keyword(s):  
Ammonium Acetate ◽  
Degradation Products ◽  
Degradation Mechanism ◽  
Stability Indicating ◽  
Quality Control Laboratory ◽  
Clenbuterol Hydrochloride ◽  
Stress Degradation ◽  
The Stability ◽  
Development And Validation

AbstractClenbuterol hydrochloride (CLT), β2 adrenergic agonist is used as a bronchodilator in the therapeutic treatment of asthma. It is important to know the stability behaviour of the drug in different degradation conditions as per ICH Q1A (R2) guidelines for safety and efficacy purpose. The main objective of the study is to develop and validate stability indicating LC-MS/MS method for the determination of Clenbuterol HCl. The separation was achieved using Phenomenex Gemini NX C18 (250*4.6 mm, 5 μ) column and the mobile phase consisting of ammonium acetate buffer (5 mM), 0.15% triethylamine (TEA), pH 7.5 with acetic acid: methanol (70:30, v/v) at flow rate 1 ml/min. The detection was done using PDA detector at 245 nm. The validation was performed as per ICH Q2 (R1) guideline. The drug was subjected to stress degradation conditions as per ICH Q1A (R2) guidelines. The significant degradation was observed in acidic (8.78%) and sunlight (liquid) (9%) condition while no degradation was observed in neutral, basic, oxidation and thermal condition. The drug and its degradation products were characterized using LC-MS/MS and the proposed degradation mechanism was communicated. The developed method was found to be stability-indicating, simple, specific, selective, sensitive, linear, accurate, robust and precise and used as a routine analysis in quality control laboratory.

Pelvic congestion syndrome and left renal compression syndrome - clinical features and therapeutic approaches

VASA ◽  
2016 ◽  
Vol 45 (4) ◽  
pp. 275-282 ◽  
Author(s):  
Christina Jeanneret ◽  
Konstantin Beier ◽  
Alexander von Weymarn ◽  
Jürg Traber
Keyword(s):  
Varicose Veins ◽  
Left Renal Vein ◽  
Standing Position ◽  
Ovarian Vein ◽  
Pelvic Congestion Syndrome ◽  
Compression Syndrome ◽  
Abstract Knowledge ◽  
Increased Risk ◽  
Definition Of ◽  
Pelvic Congestion

Abstract. Knowledge of the anatomy of the pelvic, gonadal and renal veins is important to understand pelvic congestion syndrome (PCS) and left renal vein compression syndrome (LRCS), which is also known as the nutcracker syndrome. LRCS is related to PCS and to the presence of vulvar, vaginal and pudendal varicose veins. The diagnosis of the two syndromes is difficult, and usually achieved with CT- or phlebography. The gold standard is the intravenous pressure measurement using conventional phlebography. The definition of PCS is described as pelvic pain, aggravated in the standing position and lasting for more than 6 months. Pain in the left flank and microhaematuria is seen in patients with LRCS. Women with multiple pregnancies are at increased risk of developing varicose vein recurrences with pelvic drainage and ovarian vein reflux after crossectomy and stripping of the great saphenous vein. The therapeutic options are: conservative treatment (medroxyprogesteron) or interventional (coiling of the ovarian vein) or operative treatment (clipping of the ovarian vein). Controlled prospective trials are needed to find the best treatment.

Postmodern More

Moreana ◽  
2003 ◽  
Vol 40 (Number 153- (1-2) ◽  
pp. 219-239
Author(s):  
Anne Lake Prescott
Keyword(s):  
Human Language ◽  
Thomas More ◽  
The Stability ◽  
Definition Of ◽  
Recent Critic

Thomas More is often called a “humanist,” and rightly so if the word has its usual meaning in scholarship on the Renaissance. “Humanist” has by now acquired so many different and contradictory meanings, however, that it needs to be applied carefully to the likes of More. Many postmodernists tend to use the word, pejoratively, to mean someone who believes in an autonomous self, the stability of words, reason, and the possibility of determinable meanings. Without quite arguing that More was a postmodernist avant la lettre, this essay suggests that he was not a “humanist” who stalks the pages of much recent postmodernist theory and that in fact even while remaining a devout Catholic and sensible lawyer he was quite as aware as any recent critic of the slipperiness of human selves and human language. It is time that literary critics tightened up their definition of “humanist,” especially when writing about the Renaissance.

Host-Guest Interactions on Electrode Surfaces for Immobilization of Molecular Catalysts

2020 ◽  
Author(s):  
Laurent Sévery ◽  
Jacek Szczerbiński ◽  
Mert Taskin ◽  
Isik Tuncay ◽  
Fernanda Brandalise Nunes ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Heterogeneous Systems ◽  
Catalytic Systems ◽  
New Approach ◽  
Molecular Systems ◽  
Electrode Surfaces ◽  
Catalytic Surfaces ◽  
Oxide Electrodes ◽  
The Stability ◽  
Molecular Catalysts

The strategy of anchoring molecular catalysts on electrode surfaces combines the high selectivity and activity of molecular systems with the practicality of heterogeneous systems. The stability of molecular catalysts is, however, far less than that of traditional heterogeneous electrocatalysts, and therefore a method to easily replace anchored molecular catalysts that have degraded could make such electrosynthetic systems more attractive. Here, we apply a non-covalent “click” chemistry approach to reversibly bind molecular electrocatalysts to electrode surfaces via host-guest complexation with surface-anchored cyclodextrins. The host-guest interaction is remarkably strong and allows the flow of electrons between the electrode and the guest catalyst. Electrosynthesis in both organic and aqueous media was demonstrated on metal oxide electrodes, with stability on the order of hours. The catalytic surfaces can be recycled by controlled release of the guest from the host cavities and readsorption of fresh guest. This strategy represents a new approach to practical molecular-based catalytic systems.

scholarly journals Haemostatic and thrombo-embolic complications in pregnant women with COVID-19: a systematic review and critical analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juliette Servante ◽  
Gill Swallow ◽  
Jim G. Thornton ◽  
Bethan Myers ◽  
Sandhya Munireddy ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Pregnant Women ◽  
Clinical Evidence ◽  
Case Reports ◽  
Standard Form ◽  
Test Results ◽  
Maternal Deaths ◽  
High Clinical Suspicion ◽  
Increased Risk ◽  
Definition Of

Abstract Background As pregnancy is a physiological prothrombotic state, pregnant women may be at increased risk of developing coagulopathic and/or thromboembolic complications associated with COVID-19. Methods Two biomedical databases were searched between September 2019 and June 2020 for case reports and series of pregnant women with a diagnosis of COVID-19 based either on a positive swab or high clinical suspicion where no swab had been performed. Additional registry cases known to the authors were included. Steps were taken to minimise duplicate patients. Information on coagulopathy based on abnormal coagulation test results or clinical evidence of disseminated intravascular coagulation (DIC), and on arterial or venous thrombosis, were extracted using a standard form. If available, detailed laboratory results and information on maternal outcomes were analysed. Results One thousand sixty-three women met the inclusion criteria, of which three (0.28, 95% CI 0.0 to 0.6) had arterial and/or venous thrombosis, seven (0.66, 95% CI 0.17 to 1.1) had DIC, and a further three (0.28, 95% CI 0.0 to 0.6) had coagulopathy without meeting the definition of DIC. Five hundred and thirty-seven women (56%) had been reported as having given birth and 426 (40%) as having an ongoing pregnancy. There were 17 (1.6, 95% CI 0.85 to 2.3) maternal deaths in which DIC was reported as a factor in two. Conclusions Our data suggests that coagulopathy and thromboembolism are both increased in pregnancies affected by COVID-19. Detection of the former may be useful in the identification of women at risk of deterioration.

scholarly journals Relationship between Sleep and Hypertension: Findings from the NHANES (2007–2014)

2021 ◽  
Vol 18 (15) ◽  
pp. 7867
Author(s):  
Chunnan Li ◽  
Shaomei Shang
Keyword(s):  
Blood Pressure ◽  
Sleep Disorder ◽  
Sleep Duration ◽  
Sleep Pattern ◽  
Poor Sleep ◽  
Sleep Patterns ◽  
Short Sleep Duration ◽  
Logistic Regression Models ◽  
Increased Risk ◽  
Definition Of

Background: To evaluate the association of sleep factors (sleep duration, self-reported trouble sleeping, diagnosed sleep disorder) and combined sleep behaviors with the risk of hypertension. Methods: We analyzed 12,166 adults aged 30–79 years who participated in the 2007–2014 National Health and Nutrition Examination Survey. Sleep duration, self-reported trouble sleeping and sleep disorders were collected using a standardized questionnaire. We included three sleep factors (sleep duration, self-reported trouble sleeping and sleep disorder) to generate an overall sleep score, ranging from 0 to 3. We then defined the sleep pattern as “healthy sleep pattern” (overall sleep score = 3), “intermediate sleep pattern” (overall sleep score = 2), and “poor sleep pattern” (0 ≤ overall sleep score ≤ 1) based on the overall sleep score. The definition of hypertension was based on self-reported antihypertensive medication use or biological measurement (systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg). We used weighted logistic regression models to investigate the associations between sleep and hypertension. Results: The overall prevalence of hypertension was 37.8%. A short sleep duration (OR = 1.20, 95% CI: 1.08 to 1.33, p = 0.001), self-reported trouble sleeping (OR = 1.45, 95% CI: 1.28 to 1.65, p < 0.001) and sleep disorder (OR = 1.33, 95% CI: 1.07 to 1.66, p = 0.012) were related to the risk of hypertension. Poor sleep patterns were closely correlated with the risk of hypertension (OR = 1.90, 95% CI: 1.62 to 2.24). Conclusions: Participants with poor sleep patterns were associated with an increased risk for hypertension.

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