HPLC DETERMINATION OF SILDENAFIL IN TABLETS

Objective: The popularity of Sildenafil, the widespread distribution of various products and dietary supplements with added synthetic drugs, requires reliable analysis methods. This research study aimed to develop a simple isocratic HPLC method for the determination of Sildenafil in tablet dosage forms from the local market. Methods: Separation was carried out at 30 °C, using column LiChrosorb® RP-18 (150 x 4.0 mm, 5 μm) with mobile phase consisting of acetonitrile: methanol: 0.5% triethylamine (15: 26: 59 v/v/v). The detector was set at 290 nm. The flow rate was 1.0 ml/min and the injection volume was 20 μl. Results: Linear correlation was obtained within the range 6.25–50.0 μg/ml with correlation coefficient (R2) 0.9998. The achieved limits of detection and quantitation were 0.7 and 2.2 μg/ml, respectively. Conclusion: The developed method can be applied for the quality control of Sildenafil preparations

Analysis of Gentamicin Sulfate in Medicinal Products After Expiry Date

Gentamicin is one of the most commonly prescribed antibiotics in the aminoglycoside class of drugs. This is largely due to its spectrum of action, low cost, and affordability. It is both effective against gram-positive and gram-negative organisms. Gentamicin has no oral absorption, so there are no oral dosage forms. There are various commercial products on the market that contain gentamicin in the form of solutions for intramuscular and intravenous administration, eye dosage forms, as well as those for external applications. For the purposes of the present study, by using a UV-VIS spectrophotometer, we have determined the content of gentamicin in an injectable dosage form at a concentration of 40 mg/mL in ampoules with an expiration date of 2016 or 2017

A BRIEF REVIEW OF ANALYTICAL METHODS FOR THE ESTIMATION OF TTR KINETIC STABILIZERS IN PHARMACEUTICAL FORMULATIONS AND BIOLOGICAL MATRICES

Transthyretin kinetic stabilizers are used as first-line drug therapy for transthyretin amyloid polyneuropathy mostly in patients unsuitable for liver transplantation. The two drugs prescribed in clinical practice are Tafamidis and Diflunisal. The European Medicines Agency approved Tafamidis for this prescription in 2011 and 2019 American Food and Drug Association also registered it for the same use. Diflunisal is a non-steroidal anti-inflammatory drug but its structural similarities to Tafamidis determine its “off-label” use for such clinical conditions. This review article represents the various analytical methods available in published literature for the determination of Tafamidis and Diflunisal in bulk drugs, pharmaceutical formulations, and biological matrices. Detailed information about all developed quantitative methods consisting of spectrophotometry, spectrofluorimetry, high-performance liquid chromatography with ultraviolet, fluorescence or diode array detection, liquid chromatography-tandem mass spectrometry, and voltammetry is provided and can be effectively used in the development of new analytical procedures and routine drug manufacturing or clinical practice

HPLC Determination of Amoxicillin, Tinidazole and Omeprazole in a Model Mixture

The present study examines the possibilities for the simultaneous determination of amoxicillin, tinidazole, and omeprazole in a model mixture by high-performance liquid chromatography. Chromatographic separation was performed in isocratic mode on a LiChrospher® 100 RP-18 column. The mobile phase consists of acetonitrile and phosphate buffer (0.001 M, pH 7.6) in a ratio of 40:60 v/v. The analysis was performed at a flow rate of 1.0 ml/min and a wavelength of 280 nm. The method was validated in terms of selectivity, linearity, precision and accuracy, limit of detection, and limit of quantification. The resulting correlation coefficients R2 are higher than 0.999, and the relative standard deviation does not exceed 2%

Spectrophotometric Determination of Drugs by Means of Schiff Base Formation: A Review

Molecules that do not ordinarily absorb radiation in the visible region of the spectrum can be made to do so by introducing chromogens that facilitate electronic transitions. The most commonly derivatized functional groups are aromatic nitro- (preliminary reduction required) and aromatic amino- groups.An amino compound that lacks chromophore can be assayed spectrophotometrically using a suitable carbonyl reagent. Certain amines condense with various aldehydes in strongly acidic media, giving them the ability to give color. Among many, the following aldehydes are widely used: 4-dimethylaminobenzaldehyde, vanillin, p-dimethylaminocinnamaldehyde, salicylaldehyde, etc. The reaction with aromatic amines produces Schiff bases.In this review, we have summarized and discussed the important analytical chromogenic reagents regularly used in drug analysis by visible spectrophotometric methods

Simultaneous quantitative determination of remdesivir, dexamethasone, rosuvastatin, and atorvastatin in human plasma using HPLC-UV analysis

A new reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination and quantification of two clinically proven drugs in COVID-19 treatment – remdesivir and dexamethasone – and two 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors – rosuvastatin and atorvastatin – in human plasma by isocratic elution and ultraviolet detection. A mobile phase consisting of 0.1% trifluoroacetic acid in water and acetonitrile (60:40, v/v) was used in the proposed analytical procedure, and the chromatographic determination was performed on a Purospher® RP–18 column at room temperature. The developed method was validated for linearity in the range of 1–24 µg/ml, with correlation coefficients greater than 0.998. The percentage recovery of the analyzed drugs was 100.87, 99.71, 102.41, and 93.38% for remdesivir, dexamethasone, rosuvastatin, and atorvastatin, respectively. The developed, effective, and specific method is suitable for implementation in routine quality control and clinical laboratory practice

HPLC ASSAY OF MODEL TABLET FORMULATIONS CONTAINING METRONIDAZOLE AND CIPROFLOXACIN

Objective: This paper describes development and validation of a high-performance liquid chromatographic analytical procedure for simultaneously determination of metronidazole and ciprofloxacin in a model tablet formulations.Methods: The separation was achieved with a LiChrosorb® RP-18 (250 x 4.6 mm) column, at 33 °C temperature with isocratic mode and a mobile phase containing triethylamine: o-phosphoric acid and аcetonitrile (0.02:80:20 v/v/v). The flow rate was 1.0 ml/min and the eluent was monitored at 290 nm.Results: The selected chromatographic conditions were found to separate effectively metronidazole and ciprofloxacin with a retention time of 3.46 min and 6.68 min, respectively. The method was validated for analytical parameters specificity, linearity, precision, accuracy, LOD and LOQ. The calibration curves were linear in the concentration range of 12.5-100.0 µg/ml for metronidazole and ciprofloxacin. The recovery for metronidazole and ciprofloxacin was 100.1 % and 100.2 %, respectively.Conclusion: The analytical procedure was applied to quality control of model tablet formulations. It was established that the developed analytical procedure was successfully used for routine analysis of metronidazole and ciprofloxacin in model tablet dosage forms without any interference from included excipients.Keywords: Metronidazole, Ciprofloxacin, RP-HPLC, Validation, Model tablet formulations, Quality contro

Development and validation of analytical procedure for analysis of Amoxiciline, Metronidazole and Omeprazole, used as anti- Helicobacter pylori agents alone and in mixture

Background: The contemporary treatment of ulcerogenic diseases and gastroesophageal reflux disease is related usually to application of a combination of imidazole-based antibacterial, antibiotic and proton pump inhibitor. In the current study, the three most common representatives Amoxicilline (AMO), Metronidazole (MET) and Omeprazole (OME), respectively, are subjected to analysis through classical analytical procedure, providing high level accuracy, sensitivity and good separation abilities. As such a UV/VIS method was applied as a well known identification and quantitation technique for analyses in various samples. Furthermore, this technique is known to be a good detection method in combination with chromatographic systems. Purpose: A simple, specific, accurate and precise reverse phase-high performance liquid chromatographic method has been developed for the simultaneous determination of Amoxicillin Trihydrate (AMO), Metronidazole (MET) and Omeprazole (OME) in synthetic mixture. Materials and methods: Some important parameters like pH of the mobile phase, concentration of the acid or buffer solution, percentage and type of the organic modifier, etc. were tested for a good chromatographic separation. The sample was analyzed using a mobile phase of Acetonitrile: Phosphate buffer (pH=7.6±0.1) (40:60 v/v). The flow rate was 1.0 mL/ min with detection at 280 nm. Results: The retention time for AMO, MET and OME was found to be 1.67, 2.86 and 5.99 min respectively, and the recoveries in the synthetic mixture were between 98 and 102%. The validated method was linear over the concentration range of 25 to 200 μg/mL for AMO, 12.5 to 100 μg/mL for MET and 5–40 µg/mL for OME, with a correlation coefficient > 0.999. Conclusion: The developed method has been validated in accordance with the International Conference on Harmonization (ICH) guidelines and showed excellent linearity, accuracy, precision, specificity, robustness, as well as system suitability results within the acceptance criteria

Association of BMI, lipid-lowering medication, and age with prevalence of type 2 diabetes in adults with heterozygous familial hypercholesterolaemia: a worldwide cross-sectional study

Background: Statins are the cornerstone treatment for patients with heterozygous familial hypercholesterolaemia but research suggests it could increase the risk of type 2 diabetes in the general population. A low prevalence of type 2 diabetes was reported in some familial hypercholesterolaemia cohorts, raising the question of whether these patients are protected against type 2 diabetes. Obesity is a well known risk factor for the development of type 2 diabetes. We aimed to investigate the associations of known key determinants of type 2 diabetes with its prevalence in people with heterozygous familial hypercholesterolaemia. Methods: This worldwide cross-sectional study used individual-level data from the EAS FHSC registry and included adults older than 18 years with a clinical or genetic diagnosis of heterozygous familial hypercholesterolaemia who had data available on age, BMI, and diabetes status. Those with known or suspected homozygous familial hypercholesterolaemia and type 1 diabetes were excluded. The main outcome was prevalence of type 2 diabetes overall and by WHO region, and in relation to obesity (BMI ≥30·0 kg/m2) and lipid-lowering medication as predictors. The study population was divided into 12 risk categories based on age (tertiles), obesity, and receiving statins, and the risk of type 2 diabetes was investigated using logistic regression. Findings: Among 46 683 adults with individual-level data in the FHSC registry, 24 784 with heterozygous familial hypercholesterolaemia were included in the analysis from 44 countries. 19 818 (80%) had a genetically confirmed diagnosis of heterozygous familial hypercholesterolaemia. Type 2 diabetes prevalence in the total population was 5·7% (1415 of 24 784), with 4·1% (817 of 19 818) in the genetically diagnosed cohort. Higher prevalence of type 2 diabetes was observed in the Eastern Mediterranean (58 [29·9%] of 194), South-East Asia and Western Pacific (214 [12·0%] of 1785), and the Americas (166 [8·5%] of 1955) than in Europe (excluding the Netherlands; 527 [8·0%] of 6579). Advancing age, a higher BMI category (obesity and overweight), and use of lipid-lowering medication were associated with a higher risk of type 2 diabetes, independent of sex and LDL cholesterol. Among the 12 risk categories, the probability of developing type 2 diabetes was higher in people in the highest risk category (aged 55–98 years, with obesity, and receiving statins; OR 74·42 [95% CI 47·04–117·73]) than in those in the lowest risk category (aged 18–38 years, without obesity, and not receiving statins). Those who did not have obesity, even if they were in the upper age tertile and receiving statins, had lower risk of type 2 diabetes (OR 24·42 [15·57–38·31]). The corresponding results in the genetically diagnosed cohort were OR 65·04 (40·67–104·02) for those with obesity in the highest risk category and OR 20·07 (12·73–31·65) for those without obesity. Interpretation: Adults with heterozygous familial hypercholesterolaemia in most WHO regions have a higher type 2 diabetes prevalence than in Europe. Obesity markedly increases the risk of diabetes associated with age and use of statins in these patients. Our results suggest that heterozygous familial hypercholesterolaemia does not protect against type 2 diabetes, hence managing obesity is essential to reduce type 2 diabetes in this patient population. Funding: Pfizer, Amgen, MSD, Sanofi-Aventis, Daiichi-Sankyo, and Regeneron

Novel Muscle Imaging in Inflammatory Rheumatic Diseases—A Focus on Ultrasound Shear Wave Elastography and Quantitative MRI

In recent years, imaging has played an increasing role in the clinical management of patients with rheumatic diseases with respect to aiding diagnosis, guiding therapy and monitoring disease progression. These roles have been underpinned by research which has enhanced our understanding of disease pathogenesis and pathophysiology of rheumatology conditions, in addition to their key role in outcome measurement in clinical trials. However, compared to joints, imaging research of muscles is less established, despite the fact that muscle symptoms are very common and debilitating in many rheumatic diseases. Recently, it has been shown that even though patients with rheumatoid arthritis may achieve clinical remission, defined by asymptomatic joints, many remain affected by lingering constitutional systemic symptoms like fatigue, tiredness, weakness and myalgia, which may be attributed to changes in the muscles. Recent improvements in imaging technology, coupled with an increasing clinical interest, has started to ignite new interest in the area. This perspective discusses the rationale for using imaging, particularly ultrasound and MRI, for investigating muscle pathology involved in common inflammatory rheumatic diseases. The muscles associated with rheumatic diseases can be affected in many ways, including myositis—an inflammatory muscle condition, and myopathy secondary to medications, such as glucocorticoids. In addition to non-invasive visual assessment of muscles in these conditions, novel imaging techniques like shear wave elastography and quantitative MRI can provide further useful information regarding the physiological and biomechanical status of the muscle