ABSTRACT A simple and isocratic HPLC method with stability indicating nature was developed and then subsequently validated for simultaneous determination of ciprofloxacin and dexamethasone in pharmaceutical formulations, human serum and urine. Best chromatographic separations were attained within run time of 10 minutes using C8 as stationary phase and mixture of phosphate buffer and methanol (41:59 v/v) as mobile phase. The mobile phase was flowed at 1.5 mL min−1 with detection of both the analytes at 270 nm using photodiode array detector. Validation of the method was accomplished using specificity, linearity, accuracy, precision, robustness, LOD and LOQ. The method was found linear from 3-21 mg mL−1 for ciprofloxacin (r2 ≥ 0.999) and 1-7 mg mL−1 for dexamethasone (r2 ≥ 0.999). The %age recoveries of ciprofloxacin in spiked human urine and serum were ≥99% and ≥85% respectively, while for dexamethasone they were ≥97% in both matrices. The method proficiently separated the peaks of ciprofloxacin and dexamethasone from all types of interfering substances including degradation products/impurities with purity index ≥ 0.9998. The method thus was stability-indicating and can be employed for simultaneous analysis of ciprofloxacin and dexamethasone in complex matrices involving multiple components in the mixture.

Abstract In this study, conditions were optimized for development of a simple RP-HPLC method for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine. Good separation of gatifloxacin and dexamethasone from the induced degradation products was accomplished using C8 as stationary phase; 0.02 M phosphate buffer (pH 3.0) and methanol (42:58 v/v) as mobile phase. The concentration was measured with DAD at 270 nm. Linearity was observed in the range of 0.000040-0.000280 mol/L for gatifloxacin (r2≥0.999) and 0.000013-0.000091 mol/L for dexamethasone (r2≥0.999). Both the analyte peaks were completely separated from the peaks of induced degradation products as indicated by the peak purity index (≥0.9999 for both analytes). The optimized method is recommended to be used for concurrent analysis of gatifloxacin and dexamethasone in different matrices.

ORIENTATION: There is a growing body of research that indicates that personal factors such as collectivist value orientation play an important role in individuals' preference for teamwork, and an individual's propensity to work in a team is seen as a contributing factor in one's personal learning. RESEARCH PURPOSE: The purpose of this article is twofold. Firstly, the article aims to explore whether individual-level cultural values of power distance, uncertainty avoidance and masculinity-femininity interact with individual collectivist values to influence teamwork orientation. Secondly, the study aims to examine the influence of teamwork orientation on personal learning further exploring the role of perceived value congruence in this relationship. MOTIVATION FOR THE STUDY: While an extensive amount of research has been conducted on teamwork orientation, the question of how individual cultural values influence formation of teamwork orientation is still largely unanswered. This lack is especially evident with regard to how the influence of collectivism on the development of positive attitudes towards teamwork is promoted or inhibited by other values such as power distance, uncertainty avoidance and masculinity-femininity. Moreover, the current evidence about the influence of teamwork orientation on personal learning and the role of personal and contextual factors in such a relationship is still scarce. RESEARCH DESIGN, APPROACH AND METHOD: The study used a cross-sectional survey, with data collected from 120 business students engaged in project teams at a Norwegian university. All the hypothesised relationships were assessed using partial least square structural equation modelling technique. MAIN FINDINGS: The findings indicate that the link between collectivism-teamwork orientation is stronger for team members who scored high on uncertainty avoidance values and the relationship was weaker for team members who endorsed high-power distance values. Teamwork orientation was significantly associated with personal learning independent of the degree of perceived value congruence between individual member and other team members. PRACTICAL OR MANAGERIAL IMPLICATIONS: Our study offers implications for managing teams and facilitating employee learning and development in organisations. The study may also benefit teachers in higher education in facilitating students' learning through group activities. CONTRIBUTION OR VALUE-ADDED: This study provides initial evidence on the contingent effect of power distance and uncertainty avoidance in the collectivism-teamwork orientation relationship. The study further contributes to the existing literature on the effects of preference to work in teams by assessing the influence of teamwork orientation on personal learning in addition to considering the role of perceived value congruence in this relationship.

A simple, specific and accurate stability indicating RP-HPLC method was developed for the determination of acetaminophen, pamabrom and pyrilamine maleate simultaneously in pharmaceutical dosage forms. Successful separation of all the components was enacted within 10 min using C18 column with mobile phase of methanol and acidified water (pH 1.8) in the ratio of (27: 73 v/v respectively). Flow rate of the mobile phase was 1.5 mL/min with detection at 300 nm. The method was validated in accordance with ICH guidelines. Response was a linear function of concentration over the range of 50- 150 μg/mL for acetaminophen, 2.5-7.5 μg/mL for pamabrom and 1.5-4.5 μg/mL for pyrilamine maleate. The method resulted in excellent separation of all the analytes along with their stress induced degradation products with acceptable peak tailing and good resolution. It is therefore can be applied successfully for simultaneous determination of acetaminophen, pamabrom and pyrilamine maleate in pharmaceutical formulations and their stability studies.

Se ha desarrollado un procedimiento simple y específico procedimiento para la determinación de acetaminofeno, pamabrom y maleato de pirilamina en formulaciones farmacéuticas por HPLC en fase inversa. La separación de todos los componentes se obtuvo en 10 min utilizando una columna C18 y la fase móvil compuesta por metanol y solución acuosa a pH 1.8 (con ácido sulfúrico) en relación 27: 73 v/v. La velocidad del flujo en la columna fue de 1.5 mL/min y la detección espectrofotométrica en 300 nm. El método fue validado siguiendo los criterios ICH. La respuesta fue lineal en el intervalo de concentraciones 50- 150 μg/mL para acetaminofeno, 2.5-7.5 μg/mL para pamabrom y 1.5-4.5 μg/mL para maleato de pirilamina. El procedimiento permitió la separación de los tres analitos y de sus productos de degradación inducidos en condiciones de estrés con aceptable simetría de picos y resolución cromatográfica. Es por ello que este procedimiento puede ser empleado para la determinación de acetaminofeno, pamabrom y maleato de pirilamina en formulaciones farmacéuticas y en estudios de su estabilidad.

Utilizou-se abordagem de viabilidade custo-efetividade e isocrática, baseada em CLAE, empregando coluna C-18 (250 mm x 4,6 mm, 5 µm) para separar e avaliar os fármacos, rosuvastatina, anlodipino e seus produtos de degradação induzida por estresse, simultaneamente, em formulações farmacêuticas. Focada nos parâmetros das diretrizes da ICH, a separação eficiente de ambos os fármacos e de seus produtos de degradação foi obtida por meio da otimização da fase móvel com mistura de solventes 30:70 (v/v), respectivamente, acetonitrila e tampão acetato de amônio O,1 M (pH 5). A velocidade de fluxo da fase móvel foi de 1,5 mL/min e todas as detecções foram realizadas em 240 nm, utilizando detector de UV. O método foi linear no intervalo de concentração de 1-200 µg/mL para a rosuvastatina com coeficiente de determinação 0,996. Para o anlodipino, a linearidade ficou na faixa de 0.5-100 µg/mL, com coeficiente de determinação 0,994. Ambos os fármacos, junto com seus produtos de degradação, foram separados em menos de vinte minutos. Os resultados de precisão intra-dia e inter-dia variaram de 0,72 a 1,81% para a rosuvastatina e de 0,83 a 1,88%, para o anlodipino. Os resultados mostram que este método validado pelo ICH pode ser empregado com sucesso tanto para a rotina quanto para a quantificação simultânea da estabilidade de ambos os ingredientes ativos em formulações farmacêuticas.

A viable cost-effective and isocratic approach employing C-18 column (250 mm × 4.6 mm, 5 µm) based HPLC has been utilized to separate and estimate the drugs, rosuvastatin, amlodipine and their stress induced degradation products, simultaneously in pharmaceutical formulations. Focused on ICH guideline parameters, the efficient separation of both drugs and their degradation products was achieved by optimizing a 30:70 (v/v) solvent mixture of acetonitrile and 0.1 M ammonium acetate buffer (pH 5) as mobile phase. The flow rate of the mobile phase was 1.5 mL/min and all the detections were carried out at 240 nm using UV detector. The method was linear in the concentration range of 1-200 µg/mL for rosuvastatin with 0.996 coefficient of determination value. For amlodipine, linearity was in the range of 0.5-100 µg/ml with 0.994 coefficient of determination value. Both the drugs along with their degradation products were separated in less than twenty minutes. The results of within-day and between-day precision were varied from 0.72 to 1.81% for rosuvastatin and 0.83 to 1.88% for amlodipine. The results show that this ICH validated method can be employed successfully for the routine as well as stability quantification of both the active ingredients simultaneously in pharmaceutical formulations.

A simple, precise, sensitive and validated reverse-phase high performance liquid chromatographic (RP-HPLC) method was developed for the simultaneous estimation of rosuvastatin and ezetimibe in human plasma. The method involved protein precipitation and extraction of both drugs from plasma using acetonitrile and then separation on a C-18 column. Both the analytes were detected at a wavelength of 240 nm using diode array detector. Mobile phase for the said separation consists of a mixture of 1.5% phosphoric acid and acetonitrile in 30:70, v/v ratio. Linearity was in the range of 0.32-267 mg/mL for rosuvastatin and 0.08-67 mg/mL for ezetimibe with coefficient of determination between 0.9997 and 0.9967. Limit of detection was 0.106 μg/mL for rosuvastatin and 0.026 mg/mL for ezetimibe whereas limit of quantification was 0.32 mg/mL and 0.08 mg/mL for rosuvastatin and ezetimibe respectively. Recovery of both the analytes was greater than 75% with RSD less than 15 %. The total run time was less than five min for the two components. The developed method can be fruitfully employed for the determination of these two drugs in human plasma.