Development of a potentiometric mefenamate ion sensor for the determination of mefenamic acid in pharmaceuticals and human blood serum

The characteristics, performance, and application of a novel and simple electrode, namely Pt vertical bar Hg vertical bar Hg-2(MF)(2)vertical bar Graphite, where MF stands for mefenamate ion, are described. This electrode responds to MF with sensitivity of (58.9 +/- 0.7) mV decade(-1) over the range 1.0 x 10(-6) to 1.0 x 10(-2) mol L-1 at pH 6.0-9.0 and a detection limit of 6.2 x 10(-7) mol L-1. The electrode is easily constructed at a relatively low cost with fast response time (within 10-25 s) and can be used for a period of 4 months without significant change in its performance characteristics. The proposed sensor displayed good selectivity for mefenamate in the presence of several substances, especially concerning carboxylate and inorganic anions. The potentiometric sensor was successfully applied to the determination of mefenamic acid in pharmaceuticals and human serum samples. (c) 2007 Elsevier B.V. All rights reserved.

Preparation, characterization and evaluation of drug-delivery systems: Pectin and mefenamic acid films

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Multimedia fate modeling and comparative impact on freshwater ecosystems of pharmaceuticals from biosolids-amended soils

This study modeled the impact on freshwater ecosystems of pharmaceuticals detected in biosolids following application on agricultural soils. The detected sulfonamides and hydrochlorothiazide displayed comparatively moderate retention in solid matrices and, therefore, higher transfer fractions from biosolids to the freshwater compartment. However, the residence times of these pharmaceuticals in freshwater were estimated to be short due to abiotic degradation processes. The non-steroidal anti-inflammatory mefenamic acid had the highest environmental impact on aquatic ecosystems and warrants further investigation. The estimation of the solid-water partitioning coefficient was generally the most influential parameter of the probabilistic comparative impact assessment. These results and the modeling approach used in this study serve to prioritize pharmaceuticals in the research effort to assess the risks and the environmental impacts on aquatic biota of these emerging pollutants.

Seizures after single-agent overdose with pharmaceutical drugs: Analysis of cases reported to a poison center.

Abstract Context. Seizures during intoxications with pharmaceuticals are a well-known complication. However, only a few studies report on drugs commonly involved and calculate the seizure potential of these drugs. Objectives. To identify the pharmaceutical drugs most commonly associated with seizures after single-agent overdose, the seizure potential of these pharmaceuticals, the age-distribution of the cases with seizures and the ingested doses. Methods. A retrospective review of acute single-agent exposures to pharmaceuticals reported to the Swiss Toxicological Information Centre (STIC) between January 1997 and December 2010 was conducted. Exposures which resulted in at least one seizure were identified. The seizure potential of a pharmaceutical was calculated by dividing the number of cases with seizures by the number of all cases recorded with that pharmaceutical. Data were analyzed using descriptive statistics. Results. We identified 15,441 single-agent exposures. Seizures occurred in 313 cases. The most prevalent pharmaceuticals were mefenamic acid (51 of the 313 cases), citalopram (34), trimipramine (27), venlafaxine (23), tramadol (15), diphenhydramine (14), amitriptyline (12), carbamazepine (11), maprotiline (10), and quetiapine (10). Antidepressants were involved in 136 cases. Drugs with a high seizure potential were bupropion (31.6%, seizures in 6 of 19 cases, 95% CI: 15.4-50.0%), maprotiline (17.5%, 10/57, 95% CI: 9.8-29.4%), venlafaxine (13.7%, 23/168, 95% CI: 9.3-19.7%), citalopram (13.1%, 34/259, 95% CI: 9.5-17.8%), and mefenamic acid (10.9%, 51/470, 95% CI: 8.4-14.0%). In adolescents (15-19y/o) 23.9% (95% CI: 17.6-31.7%) of the cases involving mefenamic acid resulted in seizures, but only 5.7% (95% CI: 3.3-9.7%) in adults (≥ 20y/o; p < 0.001). For citalopram these numbers were 22.0% (95% CI: 12.8-35.2%) and 10.9% (95% CI: 7.1-16.4%), respectively (p = 0.058). The probability of seizures with mefenamic acid, citalopram, trimipramine, and venlafaxine increased as the ingested dose increased. Conclusions. Antidepressants were frequently associated with seizures in overdose, but other pharmaceuticals, as mefenamic acid, were also associated with seizures in a considerable number of cases. Bupropion was the pharmaceutical with the highest seizure potential even if overdose with bupropion was uncommon in our sample. Adolescents might be more susceptible to seizures after mefenamic acid overdose than adults. "Part of this work is already published as a conference abstract for the XXXIV International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 27-30 May 2014, Brussels, Belgium." Abstract 8, Clin Toxicol 2014;52(4):298.

Simultaneous determination of non-steroidal anti-inflammatory drugs in pharmaceutical formulations and human serum by reversed phase high performance liquid chromatography

A rapid and sensitive method using high performance liquid chromatography has been developed and validated for the simultaneous determination of non-steroidal anti-inflammatory drugs (NSAIDs) in pharmaceutical formulations and human serum. Six NSAIDs including: naproxen sodium, diclofenac sodium, meloxicam, flurbiprofen, tiaprofenic and mefenamic acid were analyzed simultaneously in presence of ibuprofen as internal standard on Mediterranea C18 (5 µm, 250 x 0.46 mm) column. Mobile phase comprised of methanol: acetonitrile: H2O (60:20:20, v/v; pH 3.35) and pumped at a flow rate of 1 mL min-1 using 265 nm UV detection. The method was linear over a concentration range of 0.25-50 µg mL-1 (r² = 0.9999).

Remoção do ácido mefenâmico em água utilizando carvão ativado em pó, lama vermelha e oxidação com cloro

The use of activated carbon powder (ACP), red mud and oxidation with chlorine to remove mefenamic acid in water are described, aimed at their application as a complement to sewage treatment processes in Brazil. A study on the behavior of mefenamic acid in water was performed by evaluating its dissolution for different concentrations and times. Subsequently, the optimal conditions for removal of mefenamic acid were investigated using ACP adsorption at different pH and concentrations, and red mud adsorption using different pH. The utilization of different pH and times was also investigated to establish the ideal conditions for chemical oxidation of the drug. Among the different conditions studied, the best condition for drug removal by ACP and red mud were 100% and 96%, respectively, while the best condition for chemical oxidation occurred using solutions with pH 6 and 7 and reaction times of 30 and 60 minutes.

Thermal decomposition of some analgesic agents

Thermogravimetry, derivative thermogravimetry (TG, DTG) and differential scanning calorimetry (DSC), were used to study the thermal behaviour of mefenamic acid, ibuprofen, acetaminophen, sodium diclofenac, phenylbutazone, dipyrone and salicylamide. The results led to thermal stability data and also to the interpretation concerning the thermal decomposition. © 1996 Akadémial Kiadó.

Polimorfismo em medicamentos genéricos e similares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uso do ácido mefenâmico em receptoras de embriões equinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Remoção do ácido mefenâmico em solução aquosa com carvão ativado em pó e via oxidação com cloro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação da difração de raios X por policristais e do método de Rietveld de refinamento de estruturas cristalinas no estudo de polimorfos cristalinos de fármacos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Remoção do ácido mefenâmico em água utilizando carvão ativado em pó, lama vermelha e oxidação com cloro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Solubility enhancement of poorly water soluble drugs using liposome technology

The aim of this work is to investigate the various parameters that could control the encapsulation of lipophilic drugs and investigate the influence of the physical properties of poorly water-soluble drugs on bilayer loading. Initial work investigated on the solubilisation of ibuprofen, a model insoluble drug. Drug loading was assessed using HPLC and UV spectrophotometric analysis. Preliminary studies focused on the influence of bilayer composition on drug loading to obtain an optimum cholesterol concentration. This was followed up by studies investigating the effect of longer alkyl chain lipids, unsaturated alkyl chain lipids and charged lipids. The studies also focused on the effects of pH of the hydration medium and addition of the single chain surfactant a-tocopherol. The work was followed up by investigation of a range of insoluble drugs including flurbiprofen, indomethacin, sulindac, mefenamic acid, lignocaine and progesterone to investigate the influence of drugs properties and functional group on liposomal loading. The results show that no defined trend could be obtained linking the drug loading to the different drug properties including molecular weight, log P and other drug specific characteristics. However, the presence of the oppositely charged lipids improved the encapsulation of all the drugs investigated with a similar effect obtained with the substitution of the longer chain lipids. The addition of the single chain surfactant a-tocopherol resulted in enhancement of drug loading and possibly is governed by the log P of the drug candidate. Environmental scanning-electron microscopy (ESEM) was used to dynamically follow the changes in liposome morphology in real time during dehydration thereby providing a alternative assay of liposome formulation and stability. The ESEM analysis clearly demonstrated ibuprofen incorporation enhanced the stability of PC:Chol liposomes.

Levonorgestrel intrauterine system versus medical therapy for menorrhagia

Background - Menorrhagia is a common problem, yet evidence to inform decisions about therapy is limited. In a pragmatic, multicenter, randomized trial, we compared the levonorgestrel-releasing intrauterine system (levonorgestrel-IUS) with usual medical treatment in women with menorrhagia who presented to their primary care providers. Methods - We randomly assigned 571 women with menorrhagia to treatment with levonorgestrel-IUS or usual medical treatment (tranexamic acid, mefenamic acid, combined estrogen–progestogen, or progesterone alone). The primary outcome was the patient-reported score on the Menorrhagia Multi-Attribute Scale (MMAS) (ranging from 0 to 100, with lower scores indicating greater severity), assessed over a 2-year period. Secondary outcomes included general quality-of-life and sexual-activity scores and surgical intervention. Results - MMAS scores improved from baseline to 6 months in both the levonorgestrel-IUS group and the usual-treatment group (mean increase, 32.7 and 21.4 points, respectively; P<0.001 for both comparisons). The improvements were maintained over a 2-year period but were significantly greater in the levonorgestrel-IUS group than in the usual-treatment group (mean between-group difference, 13.4 points; 95% confidence interval, 9.9 to 16.9; P<0.001). Improvements in all MMAS domains (practical difficulties, social life, family life, work and daily routine, psychological well-being, and physical health) were significantly greater in the levonorgestrel-IUS group than in the usual-treatment group, and this was also true for seven of the eight quality-of-life domains. At 2 years, more of the women were still using the levonorgestrel-IUS than were undergoing the usual medical treatment (64% vs. 38%, P<0.001). There were no significant between-group differences in the rates of surgical intervention or sexual-activity scores. There were no significant differences in serious adverse events between groups. Conclusions - In women with menorrhagia who presented to primary care providers, the levonorgestrel-IUS was more effective than usual medical treatment in reducing the effect of heavy menstrual bleeding on quality of life. (Funded by the National Institute of Health Research Health Technology Assessment Programme; ECLIPSE Controlled-Trials.com number, ISRCTN86566246.)

Levonorgestrel intrauterine system versus medical therapy for menorrhagia

ABSTRACT: Menorrhagia is a common problem that interferes with a woman’s physical, emotional, and social life. Evidence to guide physicians for decision about therapy for heavy menstrual bleeding is lacking. One treatment option, the levonorgestrel-releasing intrauterine system (levonorgestrel-IUS), has been available in the United States since 2009. Updated meta-analyses comparing the levonorgestrel-IUS with nonhormonal and hormonal treatments showed that the levonorgestrel-IUS produced a greater reduction in menstrual blood loss at 3 to 12 months of follow-up. It is not clear whether these short-term benefits persist. Moreover, the rates of discontinuation of the levonorgestrel-IUS at 2 years are as high as 28%, and effects on bleeding-related quality of life are not known. This pragmatic, multicenter, randomized trial compared the effectiveness of the levonorgestrel-IUS with that of usual medical treatment among women with menorrhagia in a primary care setting. A total of 571 women with menorrhagia were randomized to treatment with levonorgestrel-IUS (n = 285) or usual medical treatment (n = 286). Usual treatment was tranexamic acid, mefenamic acid, combined estrogen-progestogen, or progesterone alone. The primary study outcome measure was the patient-reported score on the condition-specific Menorrhagia Multi-Attribute Scale (MMAS) assessed over a 2-year period. The MMAS scores range from 0 to 100, with lower scores indicating greater severity. Summary MMAS scores were assessed at 6, 12, and 24 months. Secondary outcome measures included general health-related quality of life, sexual-activity scores, and surgical intervention. There was a significant improvement in total MMAS scores from baseline to 6 months in both the levonorgestrel-IUS group and the usual-treatment group; the mean increase was 32.7 and 21.4 points, respectively; P < 0.001 for both comparisons. Over the 2-year follow-up, improvements were maintained in both groups but were significantly greater in the levonorgestrel-IUS group (mean between-group difference, 13.4 points; 95% confidence interval, 9.9–16.9; P < 0.001). Significantly greater improvements in all MMAS domains (practical difficulties, social life, psychological health, physical health, work and daily routine, and family life and relationships) occurred with the levonorgestrel-IUS than with the usual treatment (P < 0.001 with the use of a test for trend). This was also found for 7 of the 8 quality-of-life domains. At the 2-year end point, almost twice as many women were still using the levonorgestrel-IUS than were those receiving the usual medical treatment (64% vs 38%, P < 0.001). No significant between-group differences were noted in the rates of surgical intervention or sexual-activity scores as well as in the frequency of serious adverse events. These data show that levonorgestrel-IUS is more effective than usual medical treatment in improving the quality of life of women with menorrhagia in a primary care setting.