Development and validation of sensitive kinetic spectrophotometric method for the determination of moxifloxacin antibiotic in pure and commercial tablets.

New, accurate, sensitive and reliable kinetic spectrophotometric method for the assay of moxifloxacin hydrochloride (MOXF) in pure form and pharmaceutical formulations has been developed. The method involves the oxidative coupling reaction of MOXF with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) in the presence of Ce(IV) in an acidic medium to form colored product with lambda max at 623 and 660 nm. The reaction is followed spectrophotometrically by measuring the increase in absorbance at 623 nm as a function of time. The initial rate and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1.89-40.0 µg mL(-1) for initial rate and fixed time methods. The limit of detection for initial rate and fixed time methods is 0.644 and 0.043 µg mL(-1), respectively. Molar absorptivity for the method was found to be 0.89×10(4) L mol(-1) cm(-1). Statistical treatment of the experimental results indicates that the methods are precise and accurate. The proposed method has been applied successfully for the estimation of moxifloxacin hydrochloride in tablet dosage form with no interference from the excipients. The results are compared with the official method.

Sensitive method for the quantitative determination of risperidone in tablet dosage form by high-performance liquid chromatography using chlordiazepoxide as internal standard.

A selective, sensitive and simple reversed-phase HPLC method for the determination of risperidone in bulk powder and pharmaceutical formulations was developed and validated. Risperidone can be separated on a Supelcosil LC8 DB column (250 mm × 4.6 mm i.d., 5 µm particle size) at 40°C with a mobile phase of methanol and 0.1 M ammonium acetate pH 5.50 (60:40, v/v), pumped at flow rate 1.0 mL min(-1) and detected at 274 nm. Chlordiazepoxide hydrochloride was used as internal standard. The retention time of risperidone and chlordiazepoxide hydrochloride was found to be 5.89 and 7.65 min, respectively. The validation of the proposed method was carried out for specificity, linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The linear range was 4.0-275.0 µg mL(-1) (r(2)=0.9998) with limits of detection and quantification values of 0.48 and 1.59 µg mL(-1), respectively. The precision of the method was demonstrated using intra- and inter-day assay RSD values which were less than 3.27%, while the recovery was 99.00-101.12% (n=5). According to the validation results, the proposed method was found to be specific, accurate, precise and could be applied to the quantitative analysis of risperidone in raw material and tablets.

Simultaneous Determination of Clidinium Bromide and Chlordiazepoxide in Combined Dosage Forms by High-Performance Liquid Chromatography.

A sensitive and precise RP-HPLC method has been developed for the simultaneous estimation of clidinium bromide (CDB) and chlordiazepoxide (CDZ) in pure and pharmaceutical formulations. The separation was achieved on a Nucleodur C8 (250 × 4.6 mm i.d., 5 µm particle size) column at 25°C. CH3CN-MeOH-NH4OAc 0.1M (30 : 40 : 30, v/v/v) was used as the mobile phase at a flow rate of 1.0 mL min(-1) and detector wavelength at 218 nm. Almotriptan (ALT) was used as internal standard. The validation of the proposed method was carried out for linearity, accuracy, precision, LOD, LOQ, and robustness. The method showed good linearity in the ranges of 2.5-300.0 and 3.0-500.0 µg mL(-1) for CDB and CDZ, respectively. The percentage recovery obtained for CDB and CDZ was 100.40-103.38 and 99.98-105.59%, respectively. LOD and LOQ were 0.088 and 0.294 µg mL(-1) for CDB and 0.121 and 0.403 µg mL(-1) for CDZ, respectively. The proposed method was successfully applied to the determination of CDB and CDZ in combined dosage forms and the results tallied well with the label claim.

Novel spectrophotometric method for determination of some macrolide antibiotics in pharmaceutical formulations using 1,2-naphthoquinone-4-sulphonate.

New, simple and rapid spectrophotometric method has been developed and validated for the assay of two macrolide drugs, azithromycin (AZT) and erythromycin (ERY) in pure and pharmaceutical formulations. The proposed method was based on the reaction of AZT and ERY with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline medium at 25 °C to form an orange-colored product of maximum absorption peak at 452 nm. All variables were studied to optimize the reaction conditions and the reaction mechanism was postulated. Beer's law was obeyed in the concentration range 1.5-33.0 and 0.92-8.0 µg mL(-1) with limit of detection values of 0.026 and 0.063 µg mL(-1) for AZT and ERY, respectively. The calculated molar absorptivity values are 4.3 × 10(4) and 12.3 × 10(4) L mol(-1) cm(-1) for AZT and ERY, respectively. The proposed methods were successfully applied to the determination of AZT and ERY in formulations and the results tallied well with the label claim. The results were statistically compared with those of an official method by applying the Student's t-test and F-test. No interference was observed from the concomitant substances normally added to preparations.

Simultaneous determination of nortriptyline hydrochloride and fluphenazine hydrochloride in microgram quantities from low dosage forms by liquid chromatography-UV detection.

A novel method for the simultaneous high-performance liquid chromatographic determination of nortriptyline hydrochloride and fluphenazine hydrochloride was developed and validated. Fluvastatin sodium was used as internal standard. The determination was performed on a Hypersil Gold C8 column (250 mm × 4.6 mm i.d., 5 µm particle size) at 25 °C; the mobile phase, consisting of a mixture of formic acid (0.1 M, pH 2.16)-methanol (33:67, v/v), was delivered at a flow rate of 1.1 mL/min and detector wavelength at 251 nm. The retention time of nortriptyline, fluphenazine and fluvastatin was found to be 5.11, 8.05 and 11.38 min, respectively. Linearity ranges were 5.0-1350.0 and 10.0-1350.0 µg/mL with limit of detection values of 0.72 and 0.31 µg/mL, for nortriptyline and fluphenazine, respectively. Results of assay and recovery studies were statistically evaluated for its accuracy and precision. Correlation coefficients (r2) of the regression equations were greater than 0.999 in all cases. According to the validation results, the proposed method was found to be specific, accurate, precise and could be applied to the simultaneous quantitative analysis of nortriptyline and fluphenazine.

A novel use of oxidative coupling reactions for determination of some statins (cholesterol-lowering drugs) in pharmaceutical formulations.

New, accurate and reliable spectrophotometric methods for the assay of three statin drugs, atorvastatin calcium (AVS), fluvastatin sodium (FVS) and pravastatin sodium (PVS) in pure form and pharmaceutical formulations have been described. All methods involve the oxidative coupling reaction of AVS, FVS and PVS with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) in the presence of Ce(IV) in an acidic medium to form colored products with λ(max) at 566, 615 and 664 nm, respectively. Beer's law was obeyed in the ranges of 2.0-20.0, 4.9-35.4 and 7.0-30.0 µg mL(-1) for AVS-MBTH, FVS-MBTH and PVS-MBTH, respectively. Molar absorptivities for the above three methods were found to be 3.24×10(4), 1.05×10(4) and 0.68×10(4) L mol(-1) cm(-1), respectively. Statistical treatment of the experimental results indicates that the methods are precise and accurate. The proposed methods have been applied to the determination of the components in commercial forms with no interference from the excipients. A comparative study between the suggested procedures and the official methods for these compounds in the commercial forms showed no significant difference between the two methods.

Validated high-performance liquid chromatographic method for the estimation of rosuvastatin calcium in bulk and pharmaceutical formulations.

A reversed-phase high-performance liquid chromatographic method was developed and validated for the determination of rosuvastatin calcium in pharmaceutical dosage forms. The determination was performed on a Nucleodur column C8 (250 × 4.6 mm i.d., 5 µm particle size); the mobile phase consisted of a mixture of 0.1M formic acid and methanol (25:75, v/v), pumped at a flow rate 1.0 mL min(-1). The photodiode array detector was operated at 280 nm. The retention times for rosuvastatin and fluvastatin, which was used as internal standard, were 3.98 and 7.78 min, respectively. Linearity range (r (2) better than 0.999, n=6) was 3.0-1602.0 µg mL(-1) with limit of detection value of 0.12 µg mL(-1). The precision of the method was demonstrated using intra- and inter-day assay RSD% values which were less than 2.40%, while the recovery was 99.86-102.86%. The method was applied in the quality control of commercial tablets and content uniformity test and proved to be suitable for rapid and reliable quality control.

Simultaneous Determination of Miconazole Nitrate and Metronidazole in Different Pharmaceutical Dosage Forms by Gas Chromatography and Flame Ionization Detector (GC-FID).

A simple, rapid and precise gas chromatographic method has been developed for the simultaneous determination of miconazole nitrate (MIZ) and metronidazole (MNZ) in tablets and ovules, using a capillary column AE.SE-54 (15 m × 0.53 mm, i.d.) and nitrogen as a carrier gas at a flow rate of 9 mL min(-1). The oven temperature was programmed at 140°C for 3 min, with a rise of 40°C min(-1) up to 180°C (held for 2 min) and then increased to a final temperature of 250°C. The injector and detector port temperatures were maintained at 260°C. Detection was carried out using flame ionization detector. Results of assay and recovery studies were statistically evaluated for its accuracy and precision. The retention times were about 3.50 and 12.90 min for MNZ and MIZ, respectively. Linearity ranges were 50.0-6030.0 and 62.5-2000.0 µg mL(-1) for MNZ and MIZ, with limit of detection values of 2.5 and 3.1 µg mL(-1), respectively. Correlation coefficients (R(2)) of the regression equations were greater than 0.999 in all cases. No interference from any components of pharmaceutical dosage forms or degradation products was observed. According to the validation results, the proposed method was found to be specific, accurate, precise and could be applied to the simultaneous quantitative analysis of MIZ and MNZ in tablets and ovules.

Kinetic spectrophotometric determination of fluvastatin in pharmaceutical preparations.

Simple, accurate and reliable kinetic spectrophotometric method for the determination of fluvastatin sodium (FVS) in pure form and pharmaceutical formulations has been described. The method is based on the formation of colored product between FVS and 4-chloro-7-nitrobenzofurazan (NBD-Cl) in acetone medium at 55 ± 2ºC. The reaction is followed spectrophotometrically by measuring the increase in absorbance at 462 nm as a function of time. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity ranges were found to be 15.0-50.0 and 10.0-90.0 µg mL(-1) for rate data and fixed time methods, respectively. The limit of detection for rate data and fixed time methods is 0.017 and 0.134 µg mL(-1), respectively. The proposed methods have been successfully applied to the determination of fluvastatin sodium in pharmaceutical dosage forms with no interference from the excipients. Statistical comparison of the results shows that there is no significant difference between the proposed and official methods.

Quantitative determination of pravastatin in pharmaceutical dosage forms by high-performance liquid chromatography with ultraviolet detection.

A simple, sensitive and precise high-performance liquid chromatographic formulations assay for pravastatin (PVS) is described. Good chromatographic separation was achieved using a Teknokroma C8 (5 µm, 25cm × 4.6mm) column and a mobile phase consisting of 10mM ammonium acetate: methanol: triethylamine (40:60:0.17 v/v/v) while at a flow-rate of 1.0 mL min(-1). PVS was detected at 239 nm and was eluted 2.15 min after injection. No endogenous substances were found to interfere. No internal standard was required. Linearity range for PVS was 0.4-1000 µg mL(-1). The determination of intra- and inter-day precision (RSD) was less than 2.94 and 2.97%, at all concentration levels. Statistical treatment of the experimental results indicates that the method is precise and accurate. The proposed method was applied to the determination of the component in commercial tablets with no interference from the excipients. A comparative study between the suggested procedure and the pharmacopoeial method for this compound in the tablets showed no significant difference between the two methods.

Spectrophotometric Determination of Alfuzosin HCl in Pharmaceutical Formulations with some Sulphonephthalein Dyes.

Bromocresol purple (BCP), bromophenol blue (BPB) and bromothymol blue (BTB) were used to determine alfuzosin hydrochloride either in pure form or in pharmaceutical formulations. Alfuzosin was extracted as an ion-pair complex from sample solution containing KCl-HCl buffer pH2.2, 2.4 and 2.6 into CHCl3 and the absorbance was measured at 407, 413 and 412nm with use of the cited reagents, respectively. The analytical parameters and their effects on the reported systems are investigated. The reactions were extremely rapid at room temperature and the absorbance values remains unchanged up to 24 h. Beer's law was obeyed in the concentration ranges 1.20-38.3, 0.85-46.0 and 0.63-34.0 µg/ml and detection limits were 0.28, 0.24 and 0.18 µg/ml with BCP, BPB and BTB, respectively. Recoveries were 98.80-101.33%. Interferences of the other ingredients and excipients were not observed. The proposed method is simple, fast and sensitive, and the first reported extractive method for the determination of alfuzosin in commercial tablets.

Simple extractive colorimetric determination of levofloxacin by acid-dye complexation methods in pharmaceutical preparations.

Two simple and sensitive extractive spectrophotometric methods have been described for the assay of levofloxacin (LVFX) either in pure form or in pharmaceutical formulations. The developed methods involve formation of colored chloroform extractable ion-pair complexes (1:1 and 1:2 drug/dye) of levofloxacin with bromophenol blue (BPB) and bromocresol green (BCG) in aqueous acidic medium. The extracted complexes showed absorbance maxima at 424 and 428 nm for LVFX-BPB and LVFX-BCG, respectively. Beer's law is obeyed in the concentration ranges 1.85-31.5 and 1.85-25 microg ml(-1) with BPB and BCG, respectively. The methods have been applied to the determination of drug in commercial tablets. Results of analysis were validated statistically. The excipients present in the formulations do not interfere with the assay procedure.