Stability indicating RP-HPLC method for simultaneous determination of gatifloxacin and dexamethasone in binary combination

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.

Stability indicating RP-HPLC method for simultaneous determination of piroxicam and ofloxacin in binary combination.

A simple and precise RP-HPLC method was developed for simultaneous determination of piroxicam and ofloxacin in pharmaceutical formulations and human serum. Optimum separations of piroxicam, ofloxacin and stress-induced degradation products were achieved by use of Hypersil BDS C8 column (250 x 4.6mm, 5 µm). The mobile phase was a mixture of acetonitrile: 0.012M K2HPO4: 0.008M sodium citrate (both buffers mixed and pH adjusted to 2.8) (50:25:25 v/v/v) delivered at flow rate of 1.5 mL min⁻¹ using DAD at 254 nm. Response was linear function of concentration over the ranges of 70-130 mg mL⁻¹ for piroxicam and ofloxacin (r² ≥ 0.999). The method efficiently separated the analytical peaks from degradation products with acceptable tailing and resolution. The developed method was successfully used for concurrent analysis of piroxicam and ofloxacin in pharmaceutical formulations, human serum and in vitro drug interaction studies.

Simultaneous estimation of rosuvastatin and amlodipine in pharmaceutical formulations using stability indicating HPLC method

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.

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.

Simultaneous RP-HPLC determination of sparfloxacin and dexamethasone in pharmaceutical formulations

The present study describes the development and subsequent validation of simple and accurate stability indicating RP-HPLC method for the determination of sparfloxacin and dexamethasone in pharmaceutical formulations in the presence of their stress-induced degradation products. Both the drugs and their stress-induced degradation products were separated within 10 minutes using C8 column and mixture of methanol and 0.02 M phosphate buffer pH 3.0 (60:40 v/v, respectively) as mobile phase at 270 nm using diode array detector. Regression analysis showed linearity in the range of 15-105 µg/mL for sparfloxacin and 5-35 µg/mL for dexamethasone. All the analytes were adequately resolved with acceptable tailing. Peak purity of the two drugs was also greater than 0.9999, showing no co-elution peaks. The developed method was applied for simultaneous determination of sparfloxacin and dexamethasone in pharmaceutical formulations for stability studies.

O presente estudo descreve o desenvolvimento e a subsequente validação de indicador de estabilidade simples e acurada por RP-HPLC para a determinação de esparfloxacino e dexametasona em formulações farmacêuticas na presença de produtos de degradação induzidos por estresse. Tanto os fármacos quanto os produtos de degradação induzidos pelo estresse foram separados em 10 minutos, utilizando coluna C8 e mistura de methanol e tampão fosfato 0,02 M, pH 3,0 (60:40 v/v, respectivamente) como fase móvel e detector de arranjo de diodo a 270 nm, A análise de regressão mostrou linearidade na faixa de 15-105 µg/mL para esparfloxacino e 5-35 µg/mL para a dexametsona. Todos os analitos foram resolvidos adequadamente com tailing aceitável. O pico de pureza dos dois foi maior que 0.9999, não mostrando picos de co-eluição. O método desenvolvido foi aplicado para a determinação simultânea de esparfloxacino e dexametasona em formulações farmacêuticas e para estudos de estabilidade.

Stability indicating HPLC method for the simultaneous determination of moxifloxacin and prednisolone in pharmaceutical formulations.

BACKGROUND: A simple, specific, and fast stability indicating reverse phase liquid chromatographic method was established for instantaneous determination of moxifloxacin and prednisolone in bulk drugs and pharmaceutical formulations. RESULTS: Optimum chromatographic separations among the moxifloxacin, prednisolone and stress-induced degradation products were achieved within 10 minutes by use of BDS Hypersil C8 column (250 X 4.6 mm, 5 µm) as stationary phase with mobile phase consisted of a mixture of phosphate buffer (18 mM) containing 0.1% (v/v) triethylamine, at pH 2.8 (adjusted with dilute phosphoric acid) and methanol (38:62 v/v) at a flow rate of 1.5 mL min-1. Detection was performed at 254 nm using diode array detector. The method was validated in accordance with ICH guidelines. Response was a linear function of concentrations over the range of 20-80 µg mL-1 for moxifloxacin (r2 ≥ 0.998) and 40-160 µg mL-1 for prednisolone (r2 ≥ 0.998). The method was resulted in good separation of both the analytes and degradation products with acceptable tailing and resolution. The peak purity index for both the analytes after all types of stress conditions was ≥ 0.9999 indicated a complete separation of both the analyte peaks from degradation products. The method can therefore, be regarded as stabilityindicating. CONCLUSIONS: The developed method can be applied successfully for simultaneous determination of moxifloxacin and prednisolone in pharmaceutical formulations and their stability studies.

[1-(Carboxy-meth-yl)cyclo-hexyl]-methan-aminium dihydrogen phosphate.

In the title salt, C(9)H(18)NO(2) (+)·H(2)PO(4) (-), the cyclo-hexane ring is puckered, the total puckering amplitude Q(T) being 0.555 (4) Å, and an intra-molecular N-H⋯O hydrogen bond generates an S(7) ring. In the crystal structure, inter-molecular N-H⋯O and O-H⋯O hydrogen bonds lead to R(2) (2)(14), R(3) (3)(8) and R(4) (2)(8) rings, generating a two-dimensional layer.

Lamotriginium dihydrogen phosphate-4-(dimethyl-amino)-benzaldehyde (1/1).

In the title compound, C(9)H(8)Cl(2)N(5) (+)·H(2)PO(4) (-)·C(9)H(11)NO [systematic name: 3,5-diamino-6-(2,3-dichloro-phen-yl)-1,2,4-triazin-2-ium dihydrogen phosphate-4-(dimethyl-amino)-benz-alde-hyde (1/1)], inter-molecular N-H⋯O and O-H⋯O hydrogen bonds produce R(2) (2)(8) and R(3) (2)(8) rings, generating a layer. Inter-molecular N-H⋯N inter-actions also occur. The dihedral angle between the rings in the cation is 71.73 (12)°.