Ocular pharmacokinetics of acetazolamide from intravitreal implants by high-performance liquid chromatography coupled to tandem mass spectrometry.

Glaucoma, a leading cause of irreversible blindness, affects about 70 million people globally. Its treatment focuses on reducing intraocular pressure. Acetazolamide, a potent anti-glaucoma drug, is currently used only systemically due to low solubility and permeation, which cause severe side effects.

Vortex-assisted liquid-liquid microextraction combined with liquid chromatography tandem mass spectrometry for simultaneous determination of cardiovascular drugs in human plasma.

Hypertension and dyslipidemias are among the main risk factors for the development of cardiovascular diseases, which are responsible for the death of approximately 17 million people each year. There are several drugs available for the treatment of these diseases. Therefore, methods for the simultaneous analysis of several of these drugs are useful in a wide range of situations.

Acute oral toxicity, antinociceptive and antimicrobial activities of kava dried extracts and synthetic kavain.

G. Forst, popularly known as kava, is a traditional medicinal plant widely used for the treatment of anxiety and insomnia. The aim of this study was to investigate new therapeutic applications of this plant.

Biodegradable Electrospun Nanofibers: A New Approach For Rhinosinusitis Treatment.

Biodegradable polymeric nanofibers containing mometasone furoate can be a new approach to drug delivery to treat chronic rhinosinusitis, providing controlled steroid delivery to the sinonasal mucosa. This study aimed to develop biodegradable polymeric nanofibers and explore the safety of these fibers in an in vivo rabbit model. The nanofibers' development has been optimized using the Response Surface Methodology (RSM) obtained with Design of Experiments (DoE) with the best conditions related to the polymer concentration and proportion of solvents used in the electrospinning process.

Simultaneous quantitation of kavalactones in kava dry extracts: comparison of multi-standards and single standard validation approaches.

Introduction: Dried extracts of Piper methysticum G. Forst, also known as kava, has been widely used due to its anxiolytic and sedative properties. In order to assure the quality of these extracts, it is essential to accurately quantify kavalactones, known as the active principle.

Chromatographic bioanalysis of antiglaucoma drugs in ocular tissues.

Glaucoma is a heterogeneous group of multifactorial optic neuropathies and the leading cause of irreversible blindness and visual impairment. Epidemiological data has estimated that in 2020 there will be more than 80 million individuals affected by the disease worldwide. Nowadays, intraocular pressure (IOP) lowering is carried out mainly by pharmacotherapy, with different drugs.

A Rapid UPLC Method for the Simultaneous Quantitation of Caffeic Acid Derivatives in Dried Extracts of Echinacea Purpurea.

Echinacea purpurea is a traditional medicinal plant widely used as adjuvant for the treatment of respiratory and urinary infections. Caffeic acid derivatives are considered the main active markers, such as chicoric acid, caftaric acid and chlorogenic acid. An analytical method using ultra performance liquid chromatography (UPLC) and diode array detector was developed and validated, to quantify caffeic acid derivatives in commercial dried extracts of EP.

UHPLC for quality evaluation of genuine and illegal medicines containing sildenafil citrate and tadalafil.

One of the highest incidences of illegal drug products is related to phosphodiesterase-5 inhibitors, used in treatment of erectile dysfunction, including those containing sildenafil citrate and tadalafil. In this context, comprehensive evaluation of the quality of genuine and illegal medicines was performed. A simple and rapid ultra-high performance liquid chromatography (UHPLC-UV) method to quantify sildenafil and tadalafil in the presence of six degradation products was developed and validated.

A simple and sensitive HPLC-FL method for simultaneous determination of angiotensin II receptor antagonists in human plasma.

Angiotensin II receptor antagonists are one of the most widely used classes of antihypertensive drugs. In this study, an HPLC fluorescence method after protein precipitation (PPT) extraction was developed and validated for determination of olmesartan, losartan, irbesartan, and valsartan in human plasma. The separation was carried out on a Luna cyano (250 × 4.

Comparative stability of arbutin in Arctostaphylos uva-ursi by a new comprehensive stability-indicating HPLC method.

Introduction: Arbutin is a phenol glucoside found in high concentrations in bearberry leaves and associated with the antimicrobial activity of the plant. Hydroquinone can also be found in leaves or be formed by degradation of arbutin. Lengthy exposure to free hydroquinone is associated with induction of toxicity in different organs.

Liquid chromatography-tandem mass spectrometry bioanalytical method for the determination of kavain in mice plasma: Application to a pharmacokinetic study.

A simple and fast bioanalytical method for the quantification of kavain in mice plasma was developed using liquid chromatography (LC)-tandem mass spectrometry (MS/MS). A full method validation was performed, according to regulatory guidelines, employing isotopically labeled kavain as the internal standard (racemic-kavain-d3). For the quantification, [M+H] was formed using an electrospray ionization (ESI) source in the positive ion mode and multiple reaction monitoring (MRM) was employed using a quadrupole-linear ion trap (4000 QTRAP®) instrument.

Chirobiotic V Versus Chiralpak ID for the Enantioselective Chromatographic Separation of Chloroquine: Stability and Validation Study.

Chloroquine is a chiral antimalarial drug and demonstrates enantioselective pharmacodynamic and pharmacokinetic properties. However, this drug is administered as racemate. The knowledge of stereoselective aspects of these agents may be useful to better understand their mechanisms of action and to optimize their safety and/or clinical efficacy.

Level A in vitro-in vivo correlation: Application to establish a dissolution test for artemether and lumefantrine tablets.

Malaria is the most incident parasite infection worldwide. Artemisinin based combination therapy (ACT) has been proposed as a promising treatment for malaria, and artemether + lumefantrine (20 + 120 mg) is the recommended association in endemic areas. Despite its widespread use, there is still scarce information about dissolution of artemether and lumefantrine, reflecting in the absence of a specific method in pharmacopoeias and international compendia.

Molecularly imprinted polymer for determination of lumefantrine in human plasma through chemometric-assisted solid-phase extraction and liquid chromatography.

Lumefantrine is the first-choice treatment of Falciparum uncomplicated malaria. Recent findings of resistance to lumefantrine has brought attention for the importance of therapeutic monitoring, since exposure to subtherapeutic doses of antimalarials after administration is a major cause of selection of resistant parasites. Therefore, this study focused on the development of innovative, selective, less expensive and stable molecularly imprinted polymers (MIPs) for solid-phase extraction (SPE) of lumefantrine from human plasma to be used in drug monitoring.

Etoposide-Loaded Poly(Lactic-co-Glycolic Acid) Intravitreal Implants: In Vitro and In Vivo Evaluation.

Etoposide-loaded poly(lactic-co-glycolic acid) implants were developed for intravitreal application. Implants were prepared by a solvent-casting method and characterized in terms of content uniformity, morphology, drug-polymer interaction, stability, and sterility. In vitro drug release was investigated and the implant degradation was monitored by the percent of mass loss.

Simultaneous Quantitation of Amlodipine Besylate and Olmesartan Medoxomil in Fixed-Dose Combination Tablets: HPLC-DAD Versus UHPLC-DAD.

Association of amlodipine besylate and olmesartan medoxomil in fixed-dose combination tablets is effective, safe and well tolerated for the treatment of hypertension. The aim of this study was to optimize and validate a novel and fast UHPLC-DAD method for simultaneous quantification of these antihypertensive drugs in tablets, using a transfer procedure from a conventional HPLC-DAD method. The HPLC separation was carried out using a C18 column (150 × 4.

Simultaneous Determination of First-Line 4-FDC Antituberculosis Drugs by UHPLC-UV and HPLC-UV: A Comparative Study.

Tuberculosis is the second most deadly infectious disease, surpassed only by HIV/AIDS, and has resulted in over 1 billion deaths in the last 200 years. The World Health Organization estimates that in 2014, 9.6 million people were infected by this disease and 1.

A comprehensive stability-indicating HPLC method for determination of chloroquine in active pharmaceutical ingredient and tablets: Identification of oxidation impurities.

Malaria is the most common parasitic disease in humans. It is estimated that 3 billion people live under the risk of contracting this disease in the world. Chloroquine (CQ) is the drug of choice to treat cases of non-complicated malaria.

Rapid Simultaneous Separation of Four Oral Antidiabetic Drugs and Quantitative Determination of Glibenclamide Using Conventional and Fused-Core Silica Columns.

Diabetes mellitus is a chronic disease with high and growing prevalence worldwide. Therefore, the development of fast and efficient methods for the QC of antidiabetic drugs is of fundamental importance. Two ultra-fast methods, using a conventional (C18 100 × 2.

Simultaneous Determination of First-Line 4-FDC Antituberculosis Drugs by UHPLC-UV and HPLC-UV: A Comparative Study.

Tuberculosis is the second most deadly infectiousdisease, surpassed only by HIV/AIDS, and hasresulted in over 1 billion deaths in the last200 years. The World Health Organization estimatesthat in 2014, 9.6 million people were infected bythis disease and 1.

Clinical Response to Donepezil in Mild and Moderate Dementia: Relationship to Drug Plasma Concentration and CYP2D6 and APOE Genetic Polymorphisms.

The clinical response to donepezil in patients with mild and moderate dementia was investigated in relation to the drug plasma concentration and APOE and CYP2D6 polymorphisms. In a prospective naturalistic observational study, 42 patients with Alzheimer's disease (AD) and AD with cerebrovascular disease who took donepezil (10 mg) for 12 months were evaluated. Their DNA was genotyped, and the donepezil plasma concentrations were measured after 3, 6, and 12 months.

Pharmacokinetics/pharmacodynamic correlations of fluconazole in murine model of cryptococcosis.

The emergence of fluconazole-resistant Cryptococcus gattii is a global concern, since this azole is the main antifungal used worldwide to treat patients with cryptococcosis. Although pharmacokinetic (PK) and pharmacodynamic (PD) indices are useful predictive factors for therapeutic outcomes, there is a scarcity of data regarding PK/PD analysis of antifungals in cryptococcosis caused by resistant strains. In this study, PK/PD parameters were determined in a murine model of cryptococcosis caused by resistant C.

Stability-indicating UHPLC method for determination of nevirapine in its bulk form and tablets: identification of impurities and degradation kinetic study.

Nevirapine (NVP), a non-nucleoside reverse transcriptase inhibitor, is a drug widely used in the treatment of Acquired Immunodeficiency Syndrome (AIDS). The evaluation of NVP stability is of fundamental importance in order to guarantee drug product efficacy, safety and quality. In this study, NVP active pharmaceutical ingredient (API) and tablets were subjected to a detailed study of forced degradation, employing several degrading agents (acid, alkaline, water, metal ions, humidity, heat, light and oxidation agents).

Development and validation of an LC-ESI-MS/MS method for the simultaneous quantification of naproxen and sumatriptan in human plasma: application to a pharmacokinetic study.

A sensitive and fast liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated for the simultaneous quantification of naproxen and sumatriptan in human plasma. A simple liquid-liquid extraction procedure, with a mixture of ethyl acetate, methyl tert-butyl ether, and dichloromethane (4:3:3, v/v), was used for the cleanup of plasma. Naratriptan and aceclofenac were employed as internal standards.

Development and Validation of an HPLC Method for Simultaneous Determination of Rifampicin, Isoniazid, Pyrazinamide, and Ethambutol Hydrochloride in Pharmaceutical Formulations.

Tuberculosis treatment consists of a fixed dose combination of rifampicin (RIF), isoniazid (INH), pyrazinamide (PYZ), and ethambutol hydrochloride (EMB). The combined treatment using various drugs is necessary for patient curing, without recrudescence, and for prevention of drug-resistant mutants, which may occur during treatment. An HPLC-diode array detector (DAD) method for the simultaneous determination of RIF, INH, PYZ, and EMB in fixed dose combination tablets was developed and validated.