Unveiling Impurities: A Comprehensive RP-HPLC Method for Accurate Atorvastatin Impurity Analysis in Pharmaceuticals Using an Accuracy Profile Approach.

Background: Accurate determination of active pharmaceutical ingredients and impurities is essential for ensuring the safety and effectiveness of medications. This study focuses on the validation of a high-performance liquid chromatography (HPLC) method for quantifying atorvastatin and its impurities, addressing a critical aspect of pharmaceutical analysis.

Objective: The primary objective is to conduct a comprehensive validation study for the HPLC method, covering specificity assessment, response function establishment, and a detailed analysis of precision, trueness, and tolerance intervals.

Simultaneous Quantification of Two Neonicotinoids Using QuEChERS-LC-MS/MS in Moroccan Spearmint (Mentha Spicata.L): Qualimetry of the Method by Uncertainty Estimation Using Generalized Pivotal Quantities Approach and Monte Carlo Simulation.

Background: Neonicotinoids (NEOs) are used for the phytosanitary treatment of Mentha Spicata.L crops, and this practice requires precise control of these harmful substances at very low concentrations.

Objective: The objective of this study is to apply an approach allowing simultaneously validation and evaluation of measurement uncertainty based on total error methodology, in order to accurately quantify the presence of two NEOs in Mentha Spicata.

Optimization of a Ligand Exchange Chromatography Method for the Enantioselective Separation of Levofloxacin and Its Chiral Impurity.

Background: Levofloxacin is a third-generation fluoroquinolone that has several advantages over its (R) ofloxacin isomer. It is used to treat different types of infection, including urinary infection and prostatitis.

Objective: A new HPLC method for the enantioselective separation of levofloxacin and its chiral impurity was developed and validated to improve the separation of the enantiomers of levofloxacin [impurity(R) and active principle (S)] by increasing the value of the resolution between the eutomer and the distomer.

Development and Validation of a UPLC-DAD Method for the Simultaneous Quantification of Eight Antihypertensive Drugs in the Pharmaceutical Matrix.

Background: Hypertension is a critical health problem; it is a prevalent risk factor for cardiovascular disease. Many treatments to combat hypertension are available, however many patients are resistant to the standard therapeutic approaches. The association of two or more substances in a fixed-dose combination is effective and tolerated as a substitute for the standard therapeutic approach.

Application of Design Space, Uncertainty, and Risk Profile Strategies to the Development and Validation of UPLC Method for the Characterization of Four Authorized Phosphodiesterase Type 5 Inhibitors to Combat Counterfeit Drugs.

Background: Counterfeit medicines are an increasing scourge that are difficult to identify and they have become industrialized and widespread through highly organized illegal channels.

Objective: This research aims to develop a robust method to determine four phosphodiesterase type-5 inhibitors in counterfeit drugs based on ultra-performance liquid chromatography.

Method: Experimental design methodology (DOE) and design space (DS) recommended by ICH Q8 were used side-by-side in the development phase to define the optimal parameters as well as the robustness of the chromatographic method.

Association of the ADAM33 gene with asthma and bronchial hyperresponsiveness.

Asthma is a common respiratory disorder characterized by recurrent episodes of coughing, wheezing and breathlessness. Although environmental factors such as allergen exposure are risk factors in the development of asthma, both twin and family studies point to a strong genetic component. To date, linkage studies have identified more than a dozen genomic regions linked to asthma.

[Unusual benign tumors of the larynx: report of 17 cases].

Rare benign tumours of the larynx (RBTL) form a heterogeneous group. The clinical picture is non-specific. Based on a series of 17 cases of RBTL treated in our department, we wish to draw attention to the diagnosis, treatment and clinical course of these tumours.

A mutation in the LDL receptor-related protein 5 gene results in the autosomal dominant high-bone-mass trait.

Osteoporosis is a complex disease that affects >10 million people in the United States and results in 1.5 million fractures annually. In addition, the high prevalence of osteopenia (low bone mass) in the general population places a large number of people at risk for developing the disease.

[Papillary carcinoma from the thyroglossal duct cyst: review of the literature and report of a case].

Cancer of a thyroglossal duct cyst is very rare. Clinical presentation is identical that of a benign cyst, and the diagnosis is histopathological. We report the case of 36 year-old woman treated for papillary carcinoma of a thyroglossal duct cyst.

[Parotid tumors: a report of 120 cases].

The treatment of the parotid tumors was clarified for a majority of the tumors, in spite of her histology diversity. The authors report in a retrospective study 120 cases of a parotid gland tumors during ten years over. They insist on the difficult of therapeutics, the histological diversity and the complications and sequelles of the surgery.

Deuterium isotope effects on caffeine metabolism.

The aim of this work was to study the influence of labelling on caffeine metabolism according to the incubation mode. It has been observed that labelling induces an isotopic effect on metabolisation speed: apparent half-lives are systematically increased. Moreover, isotopic effects are in agreement with those previously observed for retention times.

Isotopic effects on retention times of caffeine and its metabolites 1,3,7-trimethyluric acid, theophylline, theobromine and paraxanthine.

Physicochemical parameters that influence gas chromatographic separation are numerous. Consequently, isotope labelling, because it modifies physicochemical properties, can induce isotopic effects on retention time. Caffeine has been chosen to study this influence because as itself and its metabolites, it allows the preparation of different methylxanthine isotopomers and thus is one of the best models to study isotopic effects induced by stable isotope labelling.

Characterization of a flow-sorted human chromosome 10 cosmid library by FISH.

Fluoresence in situ hybridization (FISH) was used to localize cosmids to regions of human chromosome 10. A total of 301 cosmids were selected randomly from a flow-sorted human chromosome 10 cosmid library constructed from human x hamster cell line 762-8A and arrayed in microtiter storage dishes. Over 70% (211/301) of the cosmids mapped to unique regions of chromosome 10.

[Aneurysmal bone cyst of the mandible. Apropos of a case and review of the literature].

Aneurysmal bone cyst is a benign lesion, rarely found in the craniofacial region and exceptionally in the mandible. One previously unreported case originally in the mandible is presented with a review of the literature. The authors insist on pathological diagnostic and therapeutic characteristics.

[Osteoma of the frontal sinus. Apropos of 10 cases].

The authors report 10 cases of frontal sinus osteoma. The patient group consisted of 5 men and 5 women, ranging in age from 15 to 60 years. The most common revelating symptom was headache.

[Laryngocele as an etiology of respiratory distress].

Laryngocele is usually benign affection of the larynx. But serious forms of clinical emergency necessitating tracheotomy are possible. We reported 3 cases.

[Abscess of the posterior cranial fossa. Apropos of 10 cases].

In this study, a series of 10 cases of abscess of the posterior cerebral fossa is analysed. In our department, the incidence of this condition is 2 cases per year. These predominantly occur in juvenile male and are frequently caused by adjacent ENT disease.

[Mucocele of the maxillary sinus. Apropos of 3 cases].

Mucocele of the maxillary sinus is a rare affection his pathogenesis is still discussed, with a prevalence of the injury's and inflammatory's theories. The diagnosis being confirmed by computed tomography imaging ..

Gas chromatographic-mass spectrometric quantitation of tri-, di- and monomethylxanthines and uric acids from hepatocyte incubation media.

A gas chromatographic-mass spectrometric method is described for the measurement of the concentration of fourteen methylxanthines and methyluric acid metabolites of methylxanthines, especially caffeine, from cell incubation media. The method shows linearity, accuracy and recovery suitable for metabolic studies. The reproducibility of relative retention times is satisfactory (less than 0.

Pharmacokinetic equivalence of 5(ethyl(2H)5)- and unlabelled phenobarbitone.

The present study shows the absence of in vivo pharmacokinetic isotope effect on phenobarbitone (PB) C5-ethyl deuteration (PBd5) following oral administration to man of equimolar PB/PBd5 mixtures (0.40 mmol each). Plasma PB and PBd5 (17 days) and urine PB, PBd5 and parahydroxy-metabolites (PBOH, PBHOd5) levels were determined by GC-MS.

Influence of hyperlipidic food on the kinetics of slow-release formulations of theophylline.

A cross-over study of kinetics has been undertaken in 12 healthy adults volunteers using two sustained-release theophylline products that allow once a day dosing (Theo-Dur tablets and Dilatrane A.P. bead filled capsules) to compare the i.

Simultaneous quantitation of phenobarbitone and p-hydroxyphenobarbitone and their perdeuteroethyl analogues in biological fluids by combined gas chromatography-mass spectrometry.

In order to develop 5-pentadeuteroethyl-5-phenyl barbituric acid as an alternative tracer in pharmacokinetic and metabolic studies of phenobarbitone, and to search for possible isotope effects associated with such labelling, we propose a gas chromatographic-mass spectrometric assay for simultaneous measurement of phenobarbitone, p-hydroxyphenobarbitone and their perdeuteroethyl analogues, using [1,3-15N2,2-13C] phenobarbitone as internal standard. These compounds were extracted from plasma (50 microliter) or urine (500 microliter) and pentylated according to Greeley's method. Linear calibration curves were obtained in the concentration range from 0.