Simultaneous spectrophotometric estimation of Hydrochlorothiazide, Atenolol and Losartan potassium in tablet dosage form

Two simple, accurate and reproducible spectrophotometric methods have been developed for the simultaneous estimation of Hydrochlorothiazide (Hctz), Atenolol (Atn) and Losartan potassium (Los) in combined tablet dosage forms. The first method involves determination using the simultaneous equation method, the sampling wavelengths selected are, 272.5 nm, 224 nm and 250 nm over the concentration ranges of 0.5-30 microg/ml, 1-50 microg/ ml and 1-60 microg/ml for Hctz, Atn and Los respectively. The second method is the First order derivative method, the sampling wavelengths selected for estimation of Hctz, Atn and Los are 280.5 nm, 233 nm and 244 nm with linearity in the concentration ranges of 0.5-30 microg/ ml, 1-50 microg/ml and 1-60 microg/ml respectively. The results of the analysis were validated statistically and recovery studies were carried out as per ICH guidelines.     

Simultaneous estimation of etoricoxib and thiocolchicoside by RP-HPLC method in combined dosage forms

A simple, reproducible and efficient reverse phase high performance liquid chromatographic method was developed for simultaneous estimation of etoricoxib and thiocolchicoside in combined tablet dosage form. Formulation containing etoricoxib and thiocolchicoside is used as analgesic. Chromatography was performed on a 250 mm x 4.6 mm, 5-microm particle size, BDS Hypersil C-18 column with trifluoroacetic acid buffer (pH 2.6) and acetonitrile (75:25, v/v) as a mobile phase. The detection of the combined dosage form was carried out at 220 nm and a flow rate employed was 1.5 mL/min. The retention times were 6.6 and 3.1 min for etoricoxib and thiocolchicoside, respectively. Linearity was obtained in the concentration range 20 to 160 ppm for etoricoxib and in the range 2 to 16 ppm for thiocolchicoside with a correlation coefficient of 0.9918 and 0.9994, respectively. The results of the analysis were validated statistically and recovery studies confirmed the accuracy and precision of the proposed method.     

Sensitive method for rapid estimation of Lornoxicam in bulk and its dosage form by RP-HPLC

Lornoxicam (6-chloro-4-hydroxy-2-methyl-N-2-pyridyl-2H-thieno-[2,3-e]-1,2-thiazine-3-carboxamide-1,1-dioxide) is persist as a non-steroidal anti-inflammatory drug of the oxicam class with analgesic, anti-inflammatory and antipyretic properties. A fast, accurate and sensitive chromatographic method for estimation of Lornoxicam was developed as no official method available for detection. The chromatographic separation employs isocratic elution by utilizing an inertsil ODS-C 18 , 250 mm×4.6 mm, 5 μm columns. Mobile phase consisting of solvent (40 mL acetonitrile and 60 mL 0.1 M phosphate buffer (pH 6.8 was adjusted with triethylamine)) endowed at a flow rate of 1.0 mL/min. The analyte was detected and quantified at 290 nm using UV detector. The method was validated according to ICH guidelines, illustrating to be accurate (recovery 99.08%-101.13%) and precise (intraday (0.27-1.32) and interday (0.59-1.59))within the corresponding linear range (10-60 μg/mL) with r 2 0.9992.     

Simultaneous spectrophotometric estimation of nitazoxanide and ofloxacin in tablets

Two simple, accurate and precise spectrophotometric methods have been developed for simultaneous determination of nitazoxanide and ofloxacin in tablets. Method I is Q-absorbance ratio method which involves Q-absorbance at isobestic point (306.25 nm) and max (347.5 nm) of nitazoxanide, while method II is two wavelength method, where 244.6 nm and 273.0 nm were selected as 1 and 2 for determination of nitazoxanide and 294.3 nm and 388.1 nm were selected as 3 and 4 for determination of ofloxacin. Both drugs obeyed the Beer's law in the concentration range 2-30 μg/ml,correlation coefficient (r(2)<1). Both methods were validated statistically and recovery studies were carried out to confirm the accuracy. Commercial tablet formulation was successfully analyzed using the developed methods.     

Simultaneous determination of metoprolol succinate and amlodipine besylate in pharmaceutical dosage form by HPLC

A simple, precise, specific and accurate reverse phase HPLC method has been developed for the simultaneous determination of metoprolol succinate (MS) and amlodipine besylate (AB) in tablet dosage form. The chromatographic separation was achieved on Hypersil BDS cyano (250 mm x 4.6 mm, 5 microm) column using PDA detector. The mobile phase consisting of buffer (aqueous triethylamine pH 3) and acetonitrile in the ratio of 85:15 (v/v) at a flow rate of 1.0 mL/min was used. The method was validated according to the ICH guidelines with respect to specificity, linearity, accuracy, precision and robustness.     

Development and validation of an ultra performance liquid chromatography method for venlafaxine hydrochloride in bulk and capsule dosage form

A simple, specific, accurate, and precise ultra performance liquid chromatographic method was developed and validated for the estimation of venlafaxine hydrochloride in tablet dosage forms. A acquity TM BEH column having C18, 100×2.1 mm i.d. in isocratic mode, with mobile phase containing dipotassium hydrogen phosphate: Acetonitrile (30:70 v/v; pH 7.00 with dilute o-phosphoric acid) was used. The flow rate was 0.75 ml/min and effluents were monitored at 227 nm. The retention time of venlafaxine hydrochloride was 0.548 min. The method was validated for specificity, linearity, accuracy, precision, limit of quantification, limit of detection, robustness and solution stability. Limit of detection and limit of quantification for estimation of venlafaxine hydrochloride were found to be 6.11 μg/ml and 20.33 μg/ml, respectively. Recoveries of venlafaxine hydrochloride in tablet formulations were found to be in the range of 99.3-99.5%. Proposed method was successfully applied for the quantitative determination of venlafaxine hydrochloride in tablet dosage forms.     

HPLC法同时测定姜黄胶囊中姜黄素和胡椒碱的含量

目的:建立同时测定姜黄胶囊中姜黄素和胡椒碱的HPLC法。方法:采用HPLC检测方法,色谱柱为KromasilC18(250 mm×4.6 mm,5μm),流动相为1%柠檬酸-四氢呋喃(55∶45),用45%氢氧化钾溶液调节pH=3.0,流速为1.0mL/min,检测波长343 nm。峰面积外标法同时测定姜黄胶囊中姜黄素和胡椒碱的含量。结果:姜黄素和胡椒碱的线性范围分别为2.0~80μg/mL(r=0.999 9)和0.1~20μg/mL(r=0.999 9);加样回收率姜黄素为99.62%,RSD为0.69%;胡椒碱为99.17%,RSD为1.14%。结论:该方法具有快速、简便、准确等优点,可用于姜黄胶囊的质量控制。     

Simultaneous determination of benzocaine and cetylpiridinium chloride in tablets by first-derivative spectrophotometric method

A new spectrophotometric method for the simultaneous determination of benzocaine and cetylpiridinium chloride in pharmaceutical tablets, which does not require any preliminary separation or treatment of the samples, is described. The quantitative determination of both drugs was carried out using the first derivative values measured at 231.40 and 310.00 nm for benzocaine and at 220.70 nm for cetylpiridinium chloride using the zero-crossing method. The calibration graphs were linear in the ranges from 10 to 25 mg/l of benzocaine and from 4 to 20 mg/l of cetylpiridinium chloride. The developed method was successfully applied for the assay of pharmaceutical tablets and proved to be simple, sensitive and selective. Thermogravimetric techniques, Karl Fischer and loss on drying were also used for a stoichiometric evaluation of the substances studied.     

Validation of HPLC and UV spectrophotometric methods for the determination of meropenem in pharmaceutical dosage form

A high-performance liquid chromatographic method and a UV spectrophotometric method for the quantitative determination of meropenem, a highly active carbapenem antibiotic, in powder for injection were developed in present work. The parameters linearity, precision, accuracy, specificity, robustness, limit of detection and limit of quantitation were studied according to International Conference on Harmonization guidelines. Chromatography was carried out by reversed-phase technique on an RP-18 column with a mobile phase composed of 30 mM monobasic phosphate buffer and acetonitrile (90:10; v/v), adjusted to pH 3.0 with orthophosphoric acid. The UV spectrophotometric method was performed at 298 nm. The samples were prepared in water and the stability of meropenem in aqueous solution at 4 and 25 °C was studied. The results were satisfactory with good stability after 24 h at 4 °C. Statistical analysis by Student's t-test showed no significant difference between the results obtained by the two methods. The proposed methods are highly sensitive, precise and accurate and can be used for the reliable quantitation of meropenem in pharmaceutical dosage form.     

Stability indicating LC-method for estimation of paracetamol and lornoxicam in combined dosage form

A simple, specific and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of paracetamol and lornoxicam in tablet dosage form. A Brownlee C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.05 M potassium dihydrogen phosphate:methanol (40:60, v/v) was used. The flow rate was 1.0 ml/min and effluents were monitored at 266 nm. The retention times of paracetamol and lornoxicam were 2.7 min and 5.1 min, respectively. The linearity for paracetamol and lornoxicam were in the range of 5-200 μg/ml and 0.08-20 μg/ml, respectively. Paracetamol and lornoxicam stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The proposed method was validated and successfully applied to the estimation of paracetamol and lornoxicam in combined tablet dosage form.     

Development of a colonic release capsule dosage form and the absorption of insulin.

Since the colon is relatively low in peptidase activity and drainage into the lymphatics is maximized, a peroral dosage form was developed to deliver insulin to the colon. Microemulsions, used as a vehicle for insulin, were gelled using Cab-O-Sil, and filled into gelatin capsules pretreated with formaldehyde vapor. The capsules were coated with Eudragit NE 30 D, Eudragit S100 and cellulose acetate phthalate polymers of pH-dependent and time-controlled release mechanisms. In vitro dissolution profiles of the capsule coating, using sodium salicylate as the marker, show that dissolution of the capsule begins at 4 h, at pH 5.5, and is completed at 8 h, at pH 7.7, simulating the gastrointestinal transit and pH profile of the dog. An in vivo crossover study in beagle dogs was carried out employing the following treatments: i.v. insulin, p.o. insulin microemulsion and colonic release capsule dosage form without insulin (CRC), were used as controls, a colonic release capsule dosage form with insulin (CRI) and additionally with sodium laurylsulfate (CRIL) or aprotinin (CRIA) as sorption promoter and enzyme inhibitor, respectively. Evaluation was done by measuring the reduction in blood glucose concentration levels. The pharmacological availability (P.A.) is the ratio of the area under the baseline curve (AUC), expressed as percent glucose reduction from baseline vs time, of the p.o. dosage forms to i.v. insulin administration, corrected for body weight and dose size. The P.A. for the p.o. microemulsion, CRC, CRI, CRIL and CRIA were 2.1, 0.4, 5.0, 2.7 and 6.2%, respectively. Insulin release occurred throughout the GI tract, with the exception of the stomach. Tmax occurred at 6.4 h for CRIA; the majority of insulin is taken up after the colonic arrival time is reached in the dog (4-6 h). Duration of the reduction in blood glucose levels occurred for 14 h with the CRIA dosage form.     

Development and validation of a reversed-phase HPLC method for simultaneous estimation of ambroxol hydrochloride and azithromycin in tablet dosage form

A simple, precise and accurate reversed-phase liquid chromatographic method has been developed for the simultaneous estimation of ambroxol hydrochloride and azithromycin in tablet formulations. The chromatographic separation was achieved on a Xterra RP18 (250 mm × 4.6 mm, 5 μm) analytical column. A Mixture of acetonitrile–dipotassium phosphate (30 mM) (50:50, v/v) (pH 9.0) was used as the mobile phase, at a flow rate of 1.7 ml/min and detector wavelength at 215 nm. The retention time of ambroxol and azithromycin was found to be 5.0 and 11.5 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 dynamic ranges were from 30–180 to 250–1500 μg/ml for ambroxol hydrochloride and azithromycin, respectively. The percentage recovery obtained for ambroxol hydrochloride and azithromycin were 99.40 and 99.90%, respectively. Limit of detection and quantification for azithromycin were 0.8 and 2.3 μg/ml, for ambroxol hydrochloride 0.004 and 0.01 μg/ml, respectively. The developed method can be used for routine quality control analysis of titled drugs in combination in tablet formulation.     

A simple spectrophotometric method for the determination of beta-blockers in dosage forms

A simple, extraction-free spectrophotometric method is proposed for the analysis of some beta-blockers, namely atenolol, timolol and nadolol. The method is based on the interaction of the drugs in chloroform with 0.1% chloroformic solutions of acidic sulphophthalein dyes to form stable, yellow-coloured, ion-pair complexes peaking at 415 nm. The dyes used were bromophenol blue (BPB), bromothymol blue (BTB) and bromocresol purple (BCP). Under the optimum conditions, the three drugs could be assayed in the concentration range 1-10 microg ml(-1) with correlation coefficient (n = 5) more than 0.999 in all cases. The stoichiometry of the reaction was found to be 1:1 in all cases and the conditional stability constant (K(F)) of the complexes have been calculated. The free energy changes (DeltaG) were determined for all complexes formed. The interference likely to be introduced from co-formulated drugs was studied and their tolerance limits were determined. The proposed method was then applied to dosage-forms the percentage recoveries ranges from 99.12-100.95, and the results obtained were compared favorably with those given with the official methods.     

乘子法测定复方替硝唑含漱液中二组分的含量

目的：用乘子法同时测定复方替硝唑含漱液中二组分的含量。方法：用乘子法的原理和计算步骤处理多波长吸收度数据。结果：模拟样品中醋酸氯已定、替硝唑的平均回收率分别为99．75％，100．17％，RSD分别为0．73％，0．42％（n=10），对3个批号实际样品的测定结果与标准方法吻合。结论：与标准方法相比．该方法具有简便、快速、易于实现自动分析的优点。     

Development and validation of simultaneous spectrophotometric methods for drotaverine hydrochloride and aceclofenac from tablet dosage form

Two simple spectrophotometric methods have been developed for simultaneous estimation of drotaverine hydrochloride and aceclofenac from tablet dosage form. Method I is a simultaneous equation method (Vierodt's method), wavelengths selected are 306.5 and 276 nm. Method II is the absorbance ratio method (Q-Analysis), which employs 298.5 nm as λ(1) and 276 nm as λ(2) (λmax of AF) for formation of equations. Both the methods were found to be linear between the range of 8-32 μg/ml for drotaverine and 10-40 μg/ml for aceclofenac. The accuracy and precision were determined and found to comply with ICH guidelines. Both the methods showed good reproducibility and recovery with % RSD in the desired range. The methods were found to be rapid, specific, precise and accurate and can be successfully applied for the routine analysis of drotaverine and aceclofenac in their combined tablet dosage form.     

Validation and application of Vierordt's spectrophotometric method for simultaneous estimation of tamoxifen/coenzyme Q10 in their binary mixture and pharmaceutical dosage forms

For the sake of improving patient compliance and sustainability of chemotherapy healthcare system, both TC and CoQ10 were formulated as solid lipid nanoparticles (SLNs). The study was focused on establishing and validating a simple and reproducible spectrophotometric method for simultaneous determination of TC and CoQ10 in their binary mixture or pharmaceutical dosage forms. A new method based on simultaneous estimation of drug mixture without prior separation was developed. Validation parameters were checked with International Conference on Harmonization (ICH) guidelines. The accuracy and reproducibility of proposed method was statistically compared to HPLC. The TC and CoQ10 were quantified at absorptivity wavelengths of 236 nm and 275 nm, respectively. Calibration curves obeyed Beer's law in range of 2–14 µg/ml with a correlation coefficient (R²) of 0.999 in both methanol and simplified simulated intestinal fluid (SSIF). The %means recovery of TC and CoQ10 in pure state or binary mixture at various concentration levels were all around 100%. The low values of SD and %RSD (<2%) confirm high precision and accuracy of the proposed method. Formulated SLNs showed different %means recovery in range 81–92% for TC and 32–59% for CoQ10. The data obtained by applying simultaneous Vierordt's equations showed no statistical significance in comparison to HPLC. Vierordt's method was successfully applied as a simple, accurate, precise, and economical analysis method for estimating TC and CoQ10 concentrations in pure state, binary mixture and pharmaceutical dosage forms.