Determination of Metoclopramide Hydrochloride in Pharmaceutical Formulations using N-Oxidation Caroate.

Objectives: To develop two (titrimetric and spectrophotometric) simple, rapid, sensitive and cost-effective methods for the determination of metoclopramide (MCP) in pharmaceutical dosage forms. Materials and Methods: The titrimetric method (A) was based on the N-oxidation reaction involving the use of potassium hydrogen peroxymonosulfate and subsequent iodometric back titration of a known residual reagent. The spectrophotometric method (B) was based on derivatization of MCP with potassium hydrogen peroxymonosulfate in the presence of iodide to produce a chromogen (triiodide) with a wavelength of maximum absorption at 350 nm. Results: Method "A" was applicable over the concentration range of 0.25-3.5 mg to end volume 10 mL. In method "B", Beer's law was obeyed over the concentration range of 0.3-3.5 µg/mL with molar absorptivity of 24600 L/mol cm. The limits of quantification were calculated to be 0.25 mg/10 mL (A) and 0.2 µg/mL (B), respectively. Conclusion: The proposed methods were suitable for determination of MCP as a pure substance in tablets and injection.

Agreement and error of titration assays.

Titration assays can be used to define positivity either in terms of a change over time, i.e. seroconversion, or relative to a fixed threshold. The operating characteristics of these definitions depend on the precision of the assay. We present methods for estimating the distribution of errors, at the level of a single replicate, from the distribution of within-pair agreement. When the maximum replicate-level error is one dilution, a simple probability argument is used, with estimation by method of moments. For the more general case, a discretized Gaussian model is used, with maximumum likelihood estimation. These models fit well to eight published datasets. The discretized Gaussian model also allows the potential performance of alternative dilution factors to be assessed. For influenza hemagglutination-inhibition, the approach is compared to a previous Markov chain Monte Carlo data augmentation model. These methods allow the estimation of the underlying error distribution from observed between-replicate differences under repeatability conditions. The results can be used to guide the choice of the fold change necessary to infer seroconversion. Finer dilution factors, e.g. 1.5 rather than 2, could facilitate a better balance between the sensitivity and specificity of titration assays.

Model based analysis of carbon fluxes within microalgae-bacteria flocs using respirometric-titrimetric data.

With the emerging need of nutrient recycling in resource recovery facilities, the use of microalgae-bacteria flocs has received considerable attention in the past few years. However, although the main biological processes are already known, the complex interactions occurring between algae and bacteria are not fully understood. In this work, a combined respirometric-titrimetric unit was used to assess the microorganisms' kinetics within microalgae-bacteria flocs under different growth regimes (i.e. photoautotrophic, heterotrophic and mixotrophic) and different ratios of inorganic (IC) to organic carbon (OC) (IC:OC-ratios). Using this respirometric-titrimetric data, a new model was developed, calibrated and successfully validated. The model takes into account the heterotrophic growth of bacteria, the photoautotrophic, heterotrophic and mixotrophic growth of algae and the production and consumption of extracellular polymeric substances (EPS) by both bacteria and algae. As such, the model can be used for detailed analysis of the carbon fluxes within microalgae-bacteria flocs in an efficient way. Model analysis revealed the high importance of the EPS regulatory mechanism. Firstly, under heterotrophic growth conditions, OC-uptake occurred during the first 10-15 min. This was linked with internal OC storage (49% of added OC) and EPS production (40%), as such providing carbon reserves which can be consumed during famine conditions. Moreover, the algae were able to compete with bacteria for OC. Secondly, under photoautotrophic conditions, algae used the added IC to grow (57% of added IC) and to produce EPS (29%), which consecutively stimulated heterotrophic bacteria growth (20%). Finally, under mixotrophic conditions, low IC:OC-ratios resulted in an extensive OC-storage and EPS production (50% of added C) and an enhanced microalgal CO2 reuse, resulting in an increased algal growth of up to 29%.

Accuracy of dexmedetomidine titration in diagnosis of restless legs syndrome / 中华麻醉学杂志

The medical records of patients of both sexes with sleep disorders treated with multimodal sleep therapy for which patient controlled sleep with dexmedetomidine was the main method, aged≥18 yr, with body mass index of 18-30 kg/m 2, from February 2019 to January 2021, were collected.Dexmedetomidine 60 ml/h (4 μg/ml) was intravenously infused until non-rapid eye movement (NREM) Ⅲ phase was reached or the consumption of dexmedetomidine reached 1 μg/kg.Whether dexmedetomidine induced restless legs syndrome (RLS) was judged according to the Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 edition). When the titration was stopped and on the next day after emergence from anesthesia, clinical diagnosis was performed according to Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 edition) to determine whether RLS was combined or not.Kappa consistency analysis was used to assess the consistency between dexmedetomidine titration and the Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 Edition) in diagnosis of RLS.The sensitivity and specificity of diagnosis of RLS by dexmedetomidine titration were calculated.A total of 39 patients were included and 8 patients had RLS symptoms which were judged accroding to dexmedetomidine titration.The results of Kappa consistency test showed that there was a strong consistency between dexmedetomidine titration and Chinese guidelines for the diagnosis and treatment of restless legs syndrome (2021 edition) (Kappa value 1.0, P<0.01). The sensitivity and specificity of dexmedetomidine titration in judging RLS were 100%.In conclusion, dexmedetomidine titration can accurately judge RLS.

Experimental assessment and mathematical modelling of the growth of Chlorella vulgaris under photoautotrophic, heterotrophic and mixotrophic conditions.

Microalgae show great potential for wastewater treatment and nutrient recovery. However, microalgae cultivation and harvesting are affected by the low biomass concentrations which are inherent to the photoautotrophic growth process. Mixotrophic growth can be a solution as it increases microalgae biomass concentration independently from the incident light intensity. In this work, a combined respirometric-titrimetric unit was used to assess the microalgae kinetics during such mixotrophic growth conditions for Chlorella vulgaris. Based on the experimental results, a microalgae model was extended in order to gain more insight in the delicate balance between photoautotrophic and heterotrophic growth. The results suggest that during heterotrophic growth with light in absence of external inorganic carbon sources (i.e. photoheterotrophic growth), all CO2 produced by the heterotrophic pathway is internally recycled for photoautotrophic growth. Moreover, it was shown that photoautotrophic growth is the preferential growth mechanism under mixotrophic cultivation conditions (i.e. light + inorganic carbon + organic carbon), but that high oxygen concentrations activate the heterotrophic growth pathway to avoid photorespiration. The extended microalgae model supports these findings, with good model performance for all conducted experiments.

Structural Volume of Hippocampus and Alzheimers Disease

RESUMO Pesquisas recentes demonstram que o hipocampo apresenta uma redução de volume no final da idade adulta, mantendo uma estreita relação com o declínio cognitivo. A aquisição da imagem por diversos métodos de medição de volume nos leva a encontrar na ressonância magnética o método de destaque, pois permite quantificar o volume de determinadas estruturas cerebrais utilizando a reconstrução computadorizada tridimensional das imagens obtidas. OBJETIVOS Confirmar a existência de diferenças entre o volume hipocampal e o declínio cognitivo leve, doença de Alzheimer e cognição normal. MÉTODOS Levantamento bibliográfico de estudos que apresentassem dados referentes aos distúrbios da doença de Alzheimer, alterações macroscópicas cerebrais detectadas com softwares na ressonância magnética e segmentação. Foram adicionados estudos apenas da medição volumétrica do hipocampo, objetivando-se chegar a valores que possam estabelecer uma correlação do menor valor estrutural hipocampal e risco de desenvolvimento da doença. RESULTADOS Um total de 1.070 indivíduos foi analisado em seis estudos clínicos, demonstrando a relação da diminuição do hipocampo na neuroimagem, correlacionado com o comprometimento cognitivo leve e doença de Alzheimer. CONCLUSÕES O desenvolvimento de um valor padrão para esse fim seria bastante útil na coleta de dados, permitindo melhor compreensão de algumas alterações que podem ocorrer na cognição, determinar valores prognósticos e até, em um futuro próximo, fator de risco imagiológico para a doença.

A semi-mechanistic model describing the influence of light and temperature on the respiration and photosynthetic growth of Chlorella vulgaris.

The influence of light and temperature on microalgae kinetics has been assessed extensively and many models have been developed. However, limited attention has been paid to the influence of light and temperature on microalgae respiration and growth under conditions inducing (strong) photoinhibition and no clear consensus has been made on which model to use. Based on experimental data collected using a combined respirometer-titrimeter, a previously developed microalgae model (Decostere et al., 2016b) was first extended with a respiration process (r = rmin + δ µ). It was found that the dark respiration (rmin) was depending on both light and temperature and increased at conditions inducing photoinhibition and heat stress. Furthermore, out of five models describing the influence of light and temperature on the microalgae growth rate, the model of Dermoun et al. (1992) was determined to be the best suited model.

Avaliação do teor de vitamina C de preparados sólidos para refresco comercializados em Campo Grande-MS / Evaluation of the vitamin C content of solid preparations for soft drinks marketed in Campo Grande-MS

RESUMO Os sucos naturais têm sido amplamente substituídos pelos preparados sólidos para refresco (PSR), o que pode resultar em perda nutricional de componentes importantes, como o ácido ascórbico (AA). Dessa forma, este estudo objetivou analisar o teor de AA, determinar a acidez total titulável e o pH em amostras de PSR sabor abacaxi comercializados nos mercados varejistas de Campo Grande-MS e, além disso, caracterizar o AA empregado como substância química de referência. Foram analisadas 10 amostras de PSR sabor abacaxi, por meio do método de Tillmans modificado, e todas apresentaram teor de AA acima do mínimo exigido na dose dietética recomendada, atendendo aos requisitos da RDC n° 360/2003. Entretanto, 50% das amostras apresentaram teor de AA acima do limite máximo permitido de 20% para mais ou para menos segundo o declarado no rótulo. O estudo realizado confirmou que a utilização dos PSR é uma boa opção alimentícia para alcançar a dose diária necessária de AA a baixo custo.

SUMMARY Natural juices have been largely replaced by solid refreshments (SR), which can result in nutrient loss of important components, such as ascorbic acid (AA). Thus, this study aimed to analyze the AA content, determine the titratable total acidity and pH in samples of pineapple-flavored SR marketed in the retail markets of Campo Grande-MS and, in addition, characterize AA used as Reference Chemical Substance. Ten samples of pineapple-flavored SR were analyzed using the modified Tillmans method, and all presented AA content above the minimum required in the recommended dietary dose, meeting the requirements of RDC 360/2003. However, 50% of the samples presented AA content above the maximum allowed limit of 20% for more or less as stated on the label. The study confirmed that the use of SR is a good dietary option to achieve the necessary daily dose of AA at a low cost.

Validación de una metodología analítica por HPLC-DAD para la cuantificación de ácido benzoico complejado, en un ensayo de permeación transdérmica in vitro empleando piel de cerdo / Validation of an analytical methodology by HPLC-DAD for the quantification of complexed benzoic acid, in an in vitro transdermal permeation assay using pig skin

RESUMEN En el presente estudio se realizó la validación de una metodología analítica por cromatografía líquida de alta eficiencia con detector de arreglo de diodos (HPLC-DAD) para la cuantificación del ácido benzoico en complejos polielectrolíticos, obtenidos con Eudragit® E100. Para ello se evaluaron las características de desempeño determinando que la metodología es selectiva; lineal en el rango de concentraciones de 2 a 10 fíg/mL; precisa con un RSD inferior a un 2%; exacta con un porcentaje de recuperación de un 98,7% y se establecieron límites de cuantificación (LOQ) de 0,72 y de 1,56 (g/mL para el sistema y método respectivamente. De acuerdo a estos resultados, la metodología analítica es adecuada para evaluar la permeación in vitro, del ácido benzoico incluido en los complejos polielectrolíticos a través de piel porcina, empleando celdas de Franz.

SUMMARY This paper presents the studies carried out about the validation of an analytical methodology by high performance liquid chromatography with diode array detector (HPLC-DAD) for the quantification of benzoic acid in polyelectrolyte complexes obtained with Eudragit® E100. Performance characteristics of the methodology were evaluated, finding that this is selective; linear in the concentration range of 2 to 10 (g / mL; accurate with a RSD of less than 2%, exact with a recovery percentage of 98.7% and quantification limits of 0.72 and 1.56 fig / mL were established for the system and method respectively. According with this results, the analytical methodology is adequate to evaluate the in vitro permeation of benzoic acid, in polyelectrolyte complexes, through porcine skin in Franz cells.

Monitoring protein hydrolysis by pepsin using pH-stat: In vitro gastric digestions in static and dynamic pH conditions.

This study intends to demonstrate that acid titration at low pH is very well adapted to the monitoring of pepsin activity. After a description of the underlying principles, this approach was used during in vitro gastric digestions of a model of complex food containing 15wt% of whey proteins, according to both static (2h at pH = 3, Infogest protocol) and dynamic pH conditions (from pH 6.3 down to 2 in 1h). Pepsin activity was quantitatively assessed in all experiments through the calculation of degrees of hydrolysis (DH). Final values of 3.7 and 3.0% were obtained in static and dynamic pH conditions, respectively, and validated using an independent method. Results also show that about 92% of the peptides were detected at pH = 3, and 100% for pH≤2.5. Overall, the proposed approach proved to be very worthy to study protein hydrolysis during in vitro gastric digestions.

Development and validation of alternative methods by non-aqueous acid-base titration and derivative ultraviolet spectrophotometry for quantification of sildenafil in raw material and tablets

Sildenafil citrate (SILC) is a potent phosphodiesterase-5 inhibitor used for erectile dysfunction and pulmonary hypertension. This study shows two simple, fast and alternative analytical methods for SILC determination by non-aqueous titration and by derivative ultraviolet spectrophotometry (DUS) in active pharmaceutical ingredient and/or dosage forms. The quantitation method of SILC active pharmaceutical ingredient by non-aqueous acid-base titration was developed using methanol as solvent and 0.1 mol/L of perchloric acid in acetic acid as titrant. The endpoint was potentiometrically detected. The non-aqueous titration method shows satisfactory repeatability and intermediate precision (RSD 0.70-1.09%). The neutralization reaction occurred in the stoichiometric ratio 1:1 in methanol. The determination of SILC active pharmaceutical ingredient or dosage forms by DUS was developed in the linear range from 10 to 40 µg/mL, in 0.01 mol/L HCl, using the first order zero-peak method at λ 256 nm. The DUS method shows selectivity toward tablets excipients, appropriate linearity (R2 0.9996), trueness (recovery range 98.86-99.30%), repeatability and intermediate precision in three concentration levels (RSD 1.17-1.28%; 1.29-1.71%, respectively). Therefore, the methods developed are excellent alternatives to sophisticated instrumental methods and can be easily applied in any pharmaceutical laboratory routine due to simple and fast executions.

Clinical comparative study of oxycodone sustained-release tablet versus morphine tablet in dose titration therapy on moderate and severe chronic cancer pain / 中国医师进修杂志

Objective To observe the clinical effect and adverse reaction of oxycodone sustained-release tablet and morphine tablet in dose titration therapy on moderate and severe chronic cancer pain. Methods Sixty patients suffering from moderate and severe cancer pain, without using opioid drugs, were divided into oxycodone sustained-release tablet group and morphine tablet group by random digits table method with 30 cases each. The patients in oxycodone sustained-release tablet group were administered 10 mg oxycodone sustained-release tablet every 12 h, and the patients in morphine tablet group were administered 5 or 10 mg morphine tablet whenever needed. The total dose of opioid drugs was acquired after 24 h, and was converted into equal dose of oxycodone sustained-release tablet. The condition of pain control and adverse reaction were observed and recorded in a week. Results During the titration, the number of daily outbreak pain and daily medication in oxycodone sustained-release tablet were significantly lower than those in morphine tablet:(1.27 ± 1.53) times vs. (4.87 ± 1.98) times and (3.37 ± 1.78) times vs. (5.10 ± 2.20) times, and there were statistical differences (P0.05). At the first day after titration, the incidence of daily outbreak pain in oxycodone sustained-release tablet was significantly lower than that in morphine tablet:23.33%(7/30) vs. 53.33% (16/30), the rate of reaching steady pain control state was significantly higher than that in morphine tablet: 86.67% (26/30) vs. 63.33% (19/30), and there were statistical differences (P0.05). Conclusions The pain relief rate and side effect of oxycodone sustained-release tablet is similar to that of morphine tablet in dose titration therapy on moderate and severe chronic cancer pain, but analgesic effect is faster than morphine tablet. Oxycodone sustained-release tablet decreases the number of outbreak pain and relieves patients′ pain in the titration process. Oxycodone sustained-release tablet may have advantage of time and effect, which is worth to be widely used in clinical therapy.

Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis.

This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.

Titrimetric and spectrophotometric assay of diethylcarbamazine citrate in formulations using iodate and iodide mixture as reagents

One titrimetric and two spectrophotometric methods are proposed for the determination of diethylcarbamazine citrate (DEC) in bulk drug and in formulations using potassium iodate and potassium iodide as reagent. The methods employ the well-known analytical reaction between iodate and iodide in the presence of acid. In titrimetry (method A), the drug was treated with a measured excess of thiosulfate in the presence of unmeasured excess of iodate-iodide mixture and after a standing time of 10 min, the surplus thiosulfate was determined by back titration with iodine towards starch end point. Titrimetric assay is based on a 1:3 reaction stoichiometry between DEC and iodine and the method is applicable over 2.0-10.0 mg range. The liberated iodine is measured spectrophotometrically at 370 nm (method B) or the iodine-starch complex measured at 570 nm (method C). In both methods, the absorbance is found to be linearly dependent on the concentration of iodine, which in turn is related to DEC concentration. The calibration curves are linear over 2.5-50 and 2.5-30 µg mL-1 DEC for method B and method C, respectively. The calculated molar absorptivity and Sandell sensitivity values were 6.48×103 L mol-1 cm-1 and 0.0604 µg cm-2, respectively, for method B, and their respective values for method C are 9.96×103 L mol-1 cm-1 and 0.0393 µg cm-2. The intra-day and inter-day accuracy and precision studies were carried out according to the ICH guidelines. The methods were successfully applied to the analysis of DEC formulations.

Propõem-se titulação e dois métodos espectrofotométricos para a determinação de citrato de dietilcarbamazina (DEC) a granel e em suas formulações, usando iodato de potássio e iodeto de potássio como reagente. Os métodos utilizam a reação analítica conhecida entre iodato e iodeto, na presença de ácido. Na titulometria (Método A), o fármaco foi tratado com excesso medido de tiossulfato, na presença de excesso não medido de mistura iodato-iodeto e, depois de um tempo de repouso de 10 min, o excesso de tiossulfato foi determinado por titulação de retorno com iodo até o ponto final com amido. A titulação é baseada em reação com estequiometria 1:3 entre DEC e iodo e o método é aplicável na faixa de 2.0-10.0 mg. O iodo liberado é medido espectrofotometricamente a 370 nm (método B) ou o complexo de iodo-amido medido a 570 nm (método C). Em ambos os métodos, a absorvância é considerada linearmente dependente da concentração de iodo, a qual, por sua vez, está relacionada à concentração de DEC. As curvas de calibração são lineares para concentrações de DEC de 2.5-50 e 2.5-30 mg mL- 1 para o método B e para o método C, respectivamente. A absortividade molar calculada e os valores de sensibilidade Sandel foram 6.48×103 L mol-1 cm- 1 e 0.0604 ug cm-2, respectivamente, para o método B, e os seus respectivos valores para o método C são 9.96×103 L mol-1 cm-1 e 0.0393 mg cm-2. Os estudos de exatidão e precisão intra-dia e inter-dia foram realizados de acordo com as diretrizes da ICH. Os métodos foram aplicados com sucesso na análise de formulações de DEC.

Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis

This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.

Therapeutic effect of increasing dose of metoprolol by rapid titration method on acute myocardial in-farction / 心血管康复医学杂志

Objective:To observe and compare the therapeutic effect of metoprolol by routine increasing dose method and rapid titration method on acute myocardial infarction (AMI).Methods:A total of 60 inpatients,who were di-agnosed with AMI within 24h and without contraindications for metoprolol,were randomly divided into two groups:routine therapy group (received metoprolol using routine methods,the dose was added in seven days)and rapid ti-tration group (metoprolol was added in three days using titration).The dosage maintained with 190 mg/d after both groups reaching the target dose of 190mg/d;then therapeutic effects were observed in both groups.Results: ①There were no re-myocardial infarction,rehospitalization caused by heart failure and sudden death etc.in both groups;② Patients received echocardiography in outpatients after three months.Compared with routine increasing dose group,there was significant reduction in left ventricular end-diastolic diameter [LVEDd,(55.00±7.56)mm vs.(50.00± 5.81)mm]and significant rise in left ventricular ejection fraction [LVEF,(49.13 ± 10.18)% vs. (57.84±10.34)%]in rapid titration group,P <0.01 both.Conclusion:Rapid titration method could make the pa-tients rapidly reach the targeted dose of metoprolol and inhibit renin release earlier,block the renin-angiotensin sys-tem,and improve myocardial remodeling and cardiac function.

Rapid titrimetric and spectrophotometric determination of ofloxacin in pharmaceuticals using N-bromosuccinimide / Determinação titulométrico e espectrofotométrico rápido de ofloxacina em produtos farmacêuticos usando N -bromosuccinimida

One titrimetric and two spectrophotometric methods have been described for the determination of ofloxacin (OFX) in bulk drug and in tablets, employing N-Bromosuccinimide as an analytical reagent. The proposed methods involve the addition of a known excess of NBS to OFX in acid medium, followed by determination of unreacted NBS. In titrimetry, the unreacted NBS is determined iodometrically, and in spectrophotometry, unreacted NBS is determined by reacting with a fixed amount of either indigo carmine (Method A) or metanil yellow (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of OFX. Titrimetry allows the determination of 1-8 mg of OFX and the calculations are based on a 1:5 (OFX:NBS) reaction stoichiometry. In spectrophotometry, Beer's law is obeyed in the concentration ranges 0.5-5.0 µg/mL for method A and 0.3-3.0 µg/mL for method B. The molar absorptivities are calculated to be 5.53x10(4) and 9.24x10(4) L/mol/cm for method A and method B, respectively. The methods developed were applied to the assay of OFX in tablets, and results compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via the standard-addition method.

Descrevem-se métodos, um titulométrico e dois espectrofotométricos, para a determinação de ofloxacino (OFX) na matéria-prima e em comprimidos, empregando a N-bromossuccinimida (NBS) como reagente analítico. Os métodos propostos envolvem a adição de excesso conhecido de NBS ao OFX, em meio ácido, seguida de determinação do NBS que não reagiu. Na titulometria, o NBS que não reagiu é determinado iodometricamente e na espectrofotometria, o NBS que não reagiu é determinado pela reação com quantidade fixa de índigo carmim (Método A) ou amarelo de metanila (Método B). Em todos os métodos, a quantidade de NBS que reagiu corresponde à quantidade de OFX. A titulometria permite a determinação de 1-8 mg de OFX e os cálculos se baseiam na estequiometria de reação de 1:5 (OFX:NBS). Na espectrofotometria, a Lei de Beer é obedecida nas faixas de concentração de 0,5-5,0 µg/mL, para o método A, e de 0,3-3,0 µg/mL, para o método B, respectivamente. Os métodos desenvolvidos foram aplicados para o teste de OFX em comprimidos e os resultados foram comparados estatisticamente com aqueles do método de referência. A precisão e a confiabilidade dos métodos foram, posteriormente, verificadas por meio dos testes de recuperação via método de adição de padrão.

Novel application of hydrotropic solubilizing additives in the estimation of aspirin in tablets.

Highly concentrated aqueous solutions of various hydrotropic agents like sodium benzoate, sodium salicylate, sodium acetate, sodium citrate, nicotinamide and sodium ascorbate have been observed to enhance aqueous solubilities of a large number of poorly water-soluble drugs. In the present investigation hydrotropic solubilization technique has been employed to solubilize poorly water-soluble aspirin (analgesic and antipyretic drug) by 0.5 M ibuprofen sodium solution to carry out titrimetric analysis of aspirin in tablet dosage form. Results of analysis by proposed method and Phamacopoeial method are very comparable. Proposed method is new, rapid, simple, accurate, and reproducible. Statistical data proved the accuracy, reproducibility and the precision of proposed method.

A novel method for quantitative determination of aceclofenac in bulk drug and tablets using sodium salicylate as a hydrotropic solubilizing agent.

In titrimetric analysis costlier organic solvents are more often employed to solubilize the poorly water-soluble drugs. Volatility and pollution are drawbacks of such solvents. Various techniques are employed to enhance the aqueous solubility of poorly water-soluble drugs. Hydrotropic solubilization phenomenon has been widely used to enhance the aqueous solubility of large number of poorly water-soluble drugs. Aqueous solubility of aceclofenac bulk drug [a poorly water-soluble NSAID] was enhanced to a great extent i.e., 400 folds with 2.5 M sodium salicylate. The primary objective of the present investigation was to employ this hydrotropic solution to extract the drug from its dosage forms, precluding the use of costlier organic solvents. The proposed method of analysis is new, simple, accurate, environmentally friendly and reproducible. Statistical data proved the accuracy, reproducibility and the precision of the proposed method. The results of titrimetric analysis by use of hydrotropy compared very well with the results of Pharmacopoeial method.