Irfana Mariam

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

BackgroundA 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.ResultsOptimum 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.ConclusionsThe developed method can be applied successfully for simultaneous determination of moxifloxacin and prednisolone in pharmaceutical formulations and their stability studies.

DEVELOPMENT AND VALIDATION OF LIQUID CHROMATOGRAPHIC METHOD FOR NAPROXEN AND ESOMEPRAZOLE IN BINARY COMBINATION

The present study reports the development and validation of a simple, economic and sensitive HPLC method for the concurrent determination of naproxen and esomeprazole in pharmaceutical formulations. Isocratic chromatography was performed with C-18 column and mixture of phosphate buffer (pH 6.1) and acetonitrile in ratio of (40:60, v/v) at 1.5 mlmin-1. The eluents were monitored at 302 nm using UV detector. The method was isocratic in the range of 9.38 to 300 µgml-1 for naproxen and 0.5 to 16 µgml-1 for esomeprazole. Validation of the method was performed by testing parameters like linearity, accuracy, precision, robustness, specificity, LOD and LOQ values. In the specificity the drugs were subjected to forced degradation studies like acidic, basic, oxidative and thermal stresses. Both the analytes were separated within three minutes. As the method separates the degradation products produced during forced degradation studies from the active analytes so it can be used not only for regular determination of naproxen and esomeprazole but also for their stability studies.

DEVELOPMENT AND VALIDATION OF LIQUID CHROMATOGRAPHIC METHOD FOR GATIFLOXACIN AND KETOROLAC TROMETHAMINE IN COMBINED DOSAGE FORM

A fast, sensitive, and accurate stability indicating reverse phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for simultaneous determination of gatifloxacin and ketorolac tromethamine in combined dosage form. Chromatographic separations were achieved on BDS Hypersil C8 column (250 × 4.6 mm) with mobile phase that consisted of methanol and phosphate buffer (pH 3.0) in the ratio of (55:45 v/v) at a flow rate of 1.5 m Lmin−1. The analytes were detected at 270 nm using ultraviolet detection. The retention times of gatifloxacin and ketorolac tromethamine were found to be 2.460 and 6.366 min, respectively. When forced degradation studies were applied to both the drugs in combination, it was found that both gatifloxacin and ketorolac tromethamine were very stable under the basic, acidic, wet heat and oxidative environment. The method was linear in the concentration range of 30–90 µg mL−1 for gatifloxacin and 50–110 µg mL−1 for ketorolac tromethamine. The correlation coefficients were found to be 0.9998 and 0.9999 for gatifloxacin and ketorolac tromethamine, respectively. The method resulted in good separation of both the analytes with acceptable tailing and resolution. The developed method can be used for routine determination of gatifloxacin and ketorolac tromethamine in commercial formulations.

Stability indicating HPLC method for simultaneous determination of moxifloxacin hydrochloride and ketorolac tromethamine in pharmaceutical formulations

A simple, RP-HPLC method was established for determining moxifloxacin and ketorolac in pharmaceutical formulations. Moxifloxacin, ketorolac and their degradation products were separated using C8 column with methanol and phosphate buffer pH 3.0 (55:45 v/v) as the mobile phase. Detection was performed at 243 nm using a diode array detector. The method was validated using ICH guidelines and was linear in the range 20-140 µg mL-1 for both analytes. Good separation of both the analytes and their degradation products was achieved using this method. The developed method can be applied successfully for the determination of moxifloxacin and ketorolac.

SIMULTANEOUS DETERMINATION OF PIROXICAM AND PARACETAMOL IN PHARMACEUTICAL FORMULATIONS USING STABILITY INDICATING HPLC METHOD

A fast, simple, specific, and accurate stability indicating liquid chromatographic method is described for simultaneous determination of piroxicam and paracetamol in bulk drugs and pharmaceutical formulations. Optimum chromatographic separations among the piroxicam, paracetamol, and stress-induced degradation products were achieved within 6 min by using a Hypersil BDS C8 column as stationary phase with acetonitrile and 0.02 M phosphate buffer pH 3.0 (60:40, v/v) as the mobile phase at a flow rate of 1.0 mL min−1 with detection using a diode array detector at 254 nm. ICH guidelines were used to validate the developed method. Linearity was from 1.6–6.4 µg mL−1 for piroxicam and 26–104 µg mL−1 for paracetamol. All the analytes including the degradation products were separated with acceptable peak tailing and resolution. The peak purity index for both the analytes after all types of stress is >0.999, indicating complete separation of both analytes peaks from the stress induced degradation products. The developed method can be successfully used for simultaneous determination of piroxicam and paracetamol in pharmaceutical formulations and stability studies.

N-(4-Hydroxy­phen­yl)benzene­sulfon­amide

The title compound, C12H11NO3S, synthesized by the reaction of benzene sulfonyl chloride with para-aminophenol, is of interest as a precursor to biologically active sulfur-containing heterocyclic compounds. The structure is stabilized by N—H⋯O and O—H⋯O hydrogen bonds.

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

A stability-indicating RP-HPLC method is presented for determination of gatifloxacin and flurbiprofen in binary combination. Gatifloxacin, flurbiprofen and their degradation products were detected at 254 nm using a BDS Hypersil C8 (250 X 4.6 mm, 5 µm) column and mixture of 20 mM phosphate buffer (pH 3.0) and methanol 30:70 v/v as mobile phase. Response was linear over the range of 15-105 mg mL-1 for gatifloxacin (r2 > 0.998) and of 1.5-10.5 mg mL-1 for flurbiprofen (r2 > 0.999). The developed method efficiently separated the analytical peaks from degradation products (peak purity index > 0.9999). The method developed can be applied successfully for determination of gatifloxacin and flurbiprofen in human serum, urine, pharmaceutical formulations, and their stability studies.

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.

N-(4-Meth-oxy-phen-yl)-4-methyl-benzene-sulfonamide.

In the title compound, C14H15NO3S, the dihedral angle between the aromatic rings is 59.39 (14)° and the C—S—N—C torsion angle is −71.4 (2)°. In the crystal, a supramolecular chain running along the b axis with a C(4) graph set is formed via N—H⋯O hydrogen bonds.

L‐Ascorbate, a strong inducer of L‐dopa (3,4‐dihydroxy‐L‐phenylalanine) production from pre‐grown mycelia of Aspergillus oryzae NRRL‐1560

The inductive effect of L‐ascorbate on the microbiological production of L‐dopa (3,4‐dihydroxy‐L‐phenylalanine) from Aspergillus oryzae NRRL‐1560 was investigated. All biochemical reactions were performed aerobically using mould mycelia as a source of enzyme tyrosinase and acetate buffer (pH 3.0) as an extractant. L‐Tyrosine as a substrate was added at a level of 2.5 mg/ml. Maximal L‐dopa production (1.876 mg/ml) was achieved when L‐ascorbate (5.0 mg/ml) was added 6 min after the initiation of the biochemical reaction at 50 °C, consuming 2.144 mg/ml L‐tyrosine. The performance of fuzzy‐logic control of the reaction was found to be highly promising for improvement of the substrate conversion rate (∼80%). After optimizing the reaction conditions, particularly the addition of L‐ascorbate, an increase in L‐dopa yield of 22.96% was achieved compared with the control (without ascorbate addition) when the process variables, namely buffer pH, L‐tyrosine concentration and reaction temperature, were further identified using a two‐factorial Plackett–Burman design.