Determination of Exemestane in bulk and pharmaceutical dosage form by HPTLC

An HPTLC method for analysis of Exemestane in bulk and pharmaceutical formulation has been established and validated. The analyte was separated on aluminium plates precoated with silica gel 60 F₂₅₄. The mobile phase was chloroform:methanol 9.2:0.8 (v/v). Quantification was done by densitometric scanning at 247 nm. Response was a linear function of Exemestane concentration in the range of 100–500 μg mL⁻¹. The limit of detection and quantification for Exemestane were 5.8 and 17.58 μg mL⁻¹, respectively. Average recovery of Exemestane was 100.1, which shows that the method was free from interference from excipients present in the formulation. The established method enabled accurate, precise, and rapid analysis of Exemestane in bulk as well as pharmaceutical formulation.     

Separation and quantitation of oxprenolol in urine and pharmaceutical formulations by HPLC using a Chiralpak IC and UV detection

Abstract  

A stereoselective HPLC method has been developed for the simultaneous determination of oxprenolol enantiomers in urine and pharmaceutical products. Enantiomeric resolution of oxprenolol was achieved on cellulose tris(3,5-dichlorophenylcarbamate) immobilized onto a 5 μm spherical porous silica chiral stationary phase (CSP) known as Chiralpak IC with UV detection at 273 nm. The mobile phase consisted of n-hexane:isopropanol:triethylamine 70:30:0.1 (v/v/v) at a flow rate of 1.0 cm³/min. The method was validated for its linearity, accuracy, precision, and robustness. The calibration curves were linear over the range of 0.5–75 μg/cm³, with a detection limit of 0.1 μg/cm³ for each enantiomer. An average recovery of 99.0% and a mean relative standard deviation of 2.6% at 40.0 μg/cm³ for S-(−)- and R-(+)-enantiomers were obtained. The overall recoveries of oxprenolol enantiomers from pharmaceutical formulations were in the range 97.5–99.0%, with RSDs ranging from 0.6 to 0.8%. The mean extraction efficiency of oxprenolol from urine was in the range of 86.0–93.0% at 0.5–5 μg/cm³ for each enantiomer. The assay method proved to be suitable as a chiral quality control for oxprenolol formulations using HPLC and for therapeutic drug monitoring.     

Validated high-performance thin-layer chromatography method for determination of trigonelline in herbal extract and pharmaceutical dosage form

A new, simple, sensitive, selective, precise and robust high-performance thin-layer chromatographic (HPTLC) method for analysis of trigonelline was developed and validated for the determination of trigonelline in herbal extracts and in pharmaceutical dosage forms. Analysis of trigonelline was performed on TLC aluminium plates pre-coated with silica gel 60F-254 as the stationary phase. Linear ascending development was carried out in twin trough glass chamber saturated with mobile phase consisting of n-propanol-methanol-water (4:1:4, v/v/v) at room temperature (25 ± 2 °C). Camag TLC scanner III was used for spectrodensitometric scanning and analysis in absorbance mode at 269 nm. The system was found to give compact spots for trigonelline (R_f value of 0.46 ± 0.02). The linear regression analysis data for the calibration plots showed good linear relationship with r² = 0.9991 ± 0.0002 in the concentration range 100-1200 ng spot⁻¹ with respect to peak area. According to the International Conference on Harmonization (ICH) guidelines the method was validated for precision, recovery, robustness and ruggedness. The limits of detection and quantification were determined. The trigonelline content of herbal extracts quantified and estimated from the formulation was found to be well within limits (±5% of the labeled content of the formulations). Statistical analysis of the data showed that the method is reproducible and selective for the estimation of trigonelline.     

Development and validation of RP-HPLC method for simultaneous estimation of prednicarbate,mupirocin and ketoconazole in topical dosage forms

A simple and accurate reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for simultaneous estimation of prednicarbate (PC), mupirocin (MP) and ketoconazole (KT) in topical dosage forms. This combination is preferred for topical delivery of anti-inflammatory, antibacterial and antifungal agents for treatment of various skin disorders. The proposed RP-HPLC method utilizes a Hypersil GOLD C18, 5 μm, 250 mm × 4.6 mm i.d. column, mobile phase consisting of methanol-water (80: 20, v/v) adjusted to pH 5.0 with orthophosphoric acid in isocratic mode at the flow rate of 0.5 mL/min and UV detection at 243 nm. The method does not require any specific sample preparation except extraction of active pharmaceutical ingredients from the developed topical emulgel formulations using dichloromethane. Linearity was found in the range of 0.05–0.3 mg/L for PC and 0.4–2.4 mg/L for each of MP and KT with R ² > 0.999. The method is precise with low RSD%, accurate (overall average recovery yields: 99.92% for PC, 99.44% for MP and 99.74% for KT) and selective. Due to its simplicity and accuracy, the method is suitable for simultaneous analysis of PC, MP and KT in topical dosage forms.     

High-performance liquid chromatography quantitative analysis of ephedrine alkaloids in Ephedrae Herba on a perfluorooctyl stationary phase

Ephedrae Herba is one of the most commonly used herbal medicines, and it has been shown that most of the clinical efficacy for cold and asthma is exerted by its alkaloidal components. A simple and sensitive high-performance liquid chromatography method was developed using a perfluorooctyl column for the simultaneous determination of five alkaloids (norephedrine, norpseudoephedrine, ephedrine, pseudoephedrine, and methylephedrine) in Ephedrae Herba. The mobile phase comprising acetonitrile and 15 mM ammonium trifluoroacetate was used to elute the targets in isocratic elution mode. The method was validated for linearity (R² > 0.999), repeatability, intraday and interday precision, recoveries with trueness (93.87–110.99%), limits of detection (5.35–5.76 µg/mL), and limits of quantification (20 µg/mL). The quantitative results revealed that the developed method was precise and accurate. Then it was successfully applied to determine the difference in the contents of three batches of Ephedrae Herba from three pharmaceutical companies.     

Development and validation of a reversed-phase HPLC method with post-column iodine-azide reaction for the determination of thioguanine

A high-performance liquid chromatographic method of reversed-phase with a post-column iodineazide reaction has been developed and validated for the determination of thioguanine. Isocratic elution was performed on a column of C₁₈ using acetonitrile- water-sodium azide solution (1.5%; pH 6.5) 16: 34: 50 (v/v/v) as a mobile phase with flow-rate of 0.5 mL/min. Monitoring of unreacted iodine in post-column iodine-azide reaction induced by thioguanine resulted in its detection at 350 nm. The method applied to thioguanine was linear within the scope of values 8–100 nM (r ² > 0.9988). The relative standard deviation (RSD < 4.2%) and the recovery (>96%) prove that the intra-day precision and the accuracy were satisfactory. The lower limits of detection (LLD) and quantification (LLQ) of thioguanine were established at the levels of 6 and 8 nM, respectively. The elaborated method was validated and applied to thioguanine determination in tablets.     

Simultaneous HPTLC Determination of Escitalopram Oxalate and Clonazepam in Combined Tablets

A new, simple high-performance thin-layer chromatographic method has been established and validated for simultaneous determination of escitalopram oxalate and clonazepam in a combined tablet dosage form. The drugs were separated on aluminum plates precoated with silica gel 60 F₂₅₄; toluene–ethyl acetate–triethylamine 7:3.5:3 (v/v) was used as mobile phase. Quantitative analysis was performed by densitometric scanning at 258 nm. The method was validated for linearity, accuracy, precision, and robustness. The calibration plot was linear over the ranges 250–2,500 and 50–500 ng band⁻¹ for escitalopram oxalate and clonazepam, respectively. The method was successfully applied to the analysis of drugs in a pharmaceutical formulation.     

Determination of anthraquinones in Rhamnus purshiana using high-performance liquid chromatography coupled to diode array detector and simple ultraviolet spectroscopic analysis

A new method based on Ultraviolet spectrophotometry was developed and compared with that based on high-performance liquid chromatography for the determination and quantification of anthraquinones in the extracts of Rhamnus purshiana bark. A validated quantitative analysis of cascaroside A, cascaroside B, emodin, and aloe-emodin in these herbal products has been previously performed using high-performance liquid chromatography coupled with a diode array detector. In the high-performance liquid chromatography analysis, all the anthraquinones showed satisfactory regression (r² > 0.98) within the test ranges, and the recovery was in the range of 94–117%. The limits of detection and quantification were 0.008–0.010 and 0.029–0.035 μg/mL, respectively. Hierarchical cluster analysis and principal component analysis showed differences in the anthraquinones determined from herbal samples. Subsequently, a simple and low-cost ultraviolet spectrophotometric methodology for the quantitative analysis of the same compounds in the extracts was applied, and all the contents were determined. A paired t-test confirmed that there were no significant differences between the two methods. Our results revealed that the developed method is simple and provides the ability to discriminate and control the quality of anthraquinones in herbal products.     

Validated Flow Injection Spectrophotometric Assay for the Quality and Stability Control of Gemfibrozil Tablets

Abstract

A validated flow injection spectrophotometric assay has been developed and optimized for the determination of gemfibrozil in pharmaceutical formulations. The method is based on the direct measurement of the absorbance of the analyte—under flow conditions—in basic medium, at 276 nm. The assay was optimized in terms of sample injection volume and flow rate and validated in terms of linearity, repeatability, detection limit, accuracy, and selectivity. Linear calibration curve was obtained in the range of 20–100 mg l^?1, while the detection limit (1.4 mg l^?1), the repeatability (s _r <1.0%, n=12) and the sampling rate (30 h^?1) were satisfactory. The method was applied successfully to the quality control of one batch (batch no. 052) and the stability control of three batches (batches no. 049–051) of a gemfibrozil‐containing formulation (Prelisin^®, Cosmopharm Ltd, Greece).     

Determination of Fluoxetine in Human Plasma by Liquid Chromatography–Mass Spectrometry and Its Application

Abstract

A rapid, simple, and specific liquid chromatography–electrospray ionization–mass spectrometric method has been developed and validated for the determination of fluoxetine in human plasma. The method was validated with a linear range of 0.5–100 ng mL^?1, and the lowest limits of quantification were 0.5 ng mL^?1 for fluoxetine. The extraction efficiencies were about 65% and recoveries of method were in the range of 94.0–97.5%. The intraday relative standard deviation (RSD) was less than 11% and interday RSD was within 12%. The method has been successfully applied to the evaluation of pharmacokinetics and bioequivalence of fluoxetine.     

New Spectrophotometric Method for Azithromycin Determination

Abstract

Azithromycin (AZT), an antibiotic belonging to the family of macrolides, can be analyzed by a new spectrophotometric method based on the formation of an ion pair between this drug and an inorganic complex of (Mo(V)–thiocyanate) followed by its extraction with dichloroethane. This ion‐association complex shows an orange color and exhibits a maximum absorbance at 469 nm. The experimental conditions of the reaction were studied and optimized. The calibration graph was linear (r=0.9996) over the range 10^?6 M–10^?5 M of AZT. This simple and validated method has been successfully applied to the determination of azithromycin in pharmaceutical formulations with a mean relative standard deviation of 1.07% and mean recovery of 99.66%. The common excipients present in azithromycin formulations did not interfere in its determination. This new spectophotometric method has been applied successfully to illustrate the dissolution profiles of original tablets and generic compounds; hence, it could be employed in routine quality control of azithromycin in pharmaceutical dosage forms.     

CZE Separation of New Drugs for Treatment of Leukemia

Imatinib, bosutinib, dasatinib, pazopanib, erlotinib, canertinib and vatalanib are new developed anticancer drugs, especially for treatment of leukemia. In this article, a fast and high throughput capillary zone electrophoresis method has been developed and validated for analysis of these new drugs in pharmaceutical formulas. The method can be easily utilized for determination of all the drugs in one run what is advantageous for the quality control in pharmaceutical industry because there is no need for changing and optimization of separation conditions when changing the analyte. The separation was performed using an uncoated fused silica capillary with 100 mmol L⁻¹ sodium phosphate buffer pH 2.75, voltage of 25 kV, hydrodynamic injection time of 5 s by 50 mbar, and detection at 214 nm. Under these conditions, the analysis took about 8 min. The validation of all the drugs resulted in recoveries in the range of 84–100 %. The method showed to be precise for all the drugs with RSDs of migration times lower than 0.9 % (interday precision). A very good linearity in the validated range (5–100 μg mL⁻¹) and the limits of detection (LODs) in the range of 0.5–2.0 (μg mL⁻¹) were achieved. Finally, we proved that the method is robust by the Youden’s test. Therefore, our method can be successfully applied for analysis of the real pharmaceutical samples.

     

Simultaneous determination of azelaic and benzoic acids in topical preparations by liquid chromatography

Summary An isocratic, reversed-phase liquid chromatographic (LC) method has been developed for the simultaneous determination of azelaic and benzoic acids in pharmaceutical creams. The compounds were separated on a C₁₈ column (4 μm particles); the mobile phase was methanolwater, 40∶60, containing 10mm ammonium acetate and with the pH adjusted to 5.0. Detection was performed at 220 nm. The method was validated for accuracy, linearity, precision, and selectivity. Recoveries at levels corresponding to 80% to 120% of the declared content of the creams ranged from 99.5 to 101.8% and from 100.4 to 102.1% for azelaic and benzoic acids, respectively. The calibration graphs were linear in the ranges 20–1400 μg mL⁻¹ for azelaic acid (correlation coefficient,r ₁>0.99999), and 0.1–7.0 μg mL⁻¹ for benzoic acid (r>0.99998).     

Validated HPLC Method for Separation and Determination of Terbutaline Enantiomers

Abstract

A simple, rapid, and validated method for separation and determination of terbutaline enantiomers was developed. Terbutaline was separated and determined on a Vancomycin Chirobiotic V column (250 × 4.6 mm), using a mixture of methanol, acetic acid, and triethylamine (100:0.1:0.1% v/v/v) as a mobile phase at 20°C and at a flow rate of 1 ml/min. The UV detector was set to 276 nm. Acetyl salicylic acid (aspirin) was used as an internal standard. The applied high-performance liquid chromatography (HPLC) method allowed separation and quantification of terbutaline enantiomers with good linearity (r > 0.999) in the studied range. The relative standard deviations (RSD) were 1.10 and 1.32% for the terbutaline enantiomers with accuracy of 99.80 and 99.55. The limit of detection and limit of quantification of terbutaline enantiomers were found to be 0.05 and 0.10 µg · ml^?1, respectively. The method was validated through the parameters of linearity, accuracy, precision, and robustness. The HPLC method was applied for the quantitative determination of terbutaline in pharmaceutical formulations.     

Determination and Quantification of Pitavastatin Calcium in Tablet Dosage Formulation by HPTLC Method

Abstract

A simple, sensitive, reliable, and rapid HPTLC method has been developed for the determination of pitavastatin calcium in tablet dosage form. Identification and determination were performed on aluminum backed silica gel 60F₂₅₄ washed with methanol. The mobile phase of ethyl acetate‐methanol‐ammonia‐1 drop formic acid (7:2:0.8) calibration plots were established showing the dependence of response (peak area) on the amount chromatographed. The spot were scanned at 245 nm. The method has a linear range of 50–250 ng/spot. The method was validated for selectivity, repeatability, and accuracy. The method was used for determination of the compound in commercial pharmaceutical dosage forms. It is a more effective option than other chromatographic techniques in routine quality control.     

CZE Separation of New Drugs for Treatment of Leukemia

Imatinib, bosutinib, dasatinib, pazopanib, erlotinib, canertinib and vatalanib are new developed anticancer drugs, especially for treatment of leukemia. In this article, a fast and high throughput capillary zone electrophoresis method has been developed and validated for analysis of these new drugs in pharmaceutical formulas. The method can be easily utilized for determination of all the drugs in one run what is advantageous for the quality control in pharmaceutical industry because there is no need for changing and optimization of separation conditions when changing the analyte. The separation was performed using an uncoated fused silica capillary with 100 mmol L^?1 sodium phosphate buffer pH 2.75, voltage of 25 kV, hydrodynamic injection time of 5 s by 50 mbar, and detection at 214 nm. Under these conditions, the analysis took about 8 min. The validation of all the drugs resulted in recoveries in the range of 84–100 %. The method showed to be precise for all the drugs with RSDs of migration times lower than 0.9 % (interday precision). A very good linearity in the validated range (5–100 μg mL^?1) and the limits of detection (LODs) in the range of 0.5–2.0 (μg mL^?1) were achieved. Finally, we proved that the method is robust by the Youden’s test. Therefore, our method can be successfully applied for analysis of the real pharmaceutical samples.     

Simultaneous determination of aliskiren and hydrochlorothiazide from their pharmaceutical preparations using a validated stability‐indicating MEKC method

A stability‐indicating MEKC method was developed and validated for the simultaneous determination of aliskiren (ALI) and hydrochlorothiazide (HCTZ) in pharmaceutical formulations using ranitidine as an internal standard (IS). Optimal conditions for the separation of ALI, HCTZ and its major impurity chlorothiazide (CTZ), IS and degradation products were investigated. The method employed 47 mM Tris buffer and 47 mM anionic detergent SDS solution at pH 10.2 as the background electrolyte. MEKC method was performed on a fused‐silica capillary (40 cm) at 28°C. Applied voltage was 26 kV (positive polarity) and photodiode array (PDA) detector was set at 217 nm. The method was validated in accordance with the ICH requirements. The method was linear over the concentration range of 5–100 and 60–1200 μg/mL for HCTZ and ALI, respectively (r²>0.9997). The stability‐indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using the PDA detection. Precision and accuracy evaluated by RSD were lower than 2%. The method proved to be robust by a fractional factorial design evaluation. The proposed MEKC method was successfully applied for the quantitative analysis of ALI and HCTZ both individually and in a combined dosage tablet formulation to support the quality control.     

Quantification of Moxifloxacin and Levofloxacin in Curettage Material by SPE–LC

Moxifloxacin and levofloxacin have been quantified in dilatation and curettage samples by reversed-phase LC. High recovery (>91%) was obtained by simple and efficient solid-phase extraction. The method was validated in accordance with ICH guidelines to confirm specificity, linearity, accuracy, and precision. Response was a linear function of concentration over the range 0.010–30 μg g⁻¹ with excellent correlation coefficients (>0.997). Intra-day and inter-day precision and accuracy over the entire concentration range were less than 6.40 and 7.38%, respectively. Finally, the validated method was used for analysis of moxifloxacin and levofloxacin in dilatation and curettage material obtained from unwanted pregnancies up to 10 weeks gestation.

     

Simultaneous quantification of cefpirome and cetirizine or levocetirizine in pharmaceutical formulations and human plasma by RP-HPLC

A rapid and sensitive high-performance liquid chromatographic (HPLC) assay for the simultaneous determination and quantification of cefpirome and cetirizine or cefpirome and levocetirizine in pharmaceutical formulations and human plasma without changing the chromatographic conditions is described. Chromatographic separations were performed on a prepacked Nucleosil 120, C₁₈ (5 μm, 12.5 ± 0.46 mm) column using CH₃CN: H₂O (75: 25, v/v) as a mobile phase at a flow rate of 1 mL/min while UV detection was performed at 232 nm for monitoring the effluent. A number of other brands of C₁₈ columns were also employed which had a significant effect on the separation. The method has been validated over the concentration range of 0.5–50 μg/mL (r ₂ > 0.999). The limit of detection (LOD) and quantification (LOQ) for cefpirome and levocetirzine in pharmaceutical formulations and serum were in the range 0.24–1.31 μg/mL. Analytical recovery from human plasma was >98%, and the within and between-day relative standard deviation was <3.1%. The small sample volume and simplicity of preparation make this method suitable for use in pharmaceutical industries, drug research centers, clinical laboratories, and forensic medical centers. The text was submitted by the authors in English.     

Determination of rofecoxib,in the presence of its photodegradation product,in pharmaceutical preparations by micellar electrokinetic capillary chromatography

A simple and rapid micellar electrokinetic capillary chromatographic (MEKC) method for analysis of rofecoxib (ROF) and its photodegradation product (PDP) in pharmaceutical preparations has been developed and validated. Analyses were conducted in a fused silica capillary (72 cm effective length, 50 m i.d.) with a background electrolyte consisting of 25 mmol L^–1 borate buffer at pH 7.0 containing 15 mmol L^–1 sodium dodecyl sulfate (SDS) and 10% acetonitrile (ACN). The separation was performed by voltage-controlled system, applying 30 kV at 30 °C, detecting at 225 nm; injection was hydrodynamic at 50 mbar for 2 s. Nifedipine was used as internal standard (IS). Under the optimum conditions ROF, PDP, and IS were well separated with in 10 min. The method was validated with regard to linearity, limit of detection and quantitation, precision, accuracy, specificity, and robustness. The detection limit of the method was low, 0.8 g mL^–1, and the linearity range was wide, 2.5 to 125 g mL^–1. The method was highly efficient—5×10⁵ plates m^–1 for ROF. The method was applied to the tablet form of ROF-containing pharmaceutical preparations. The data were compared with those from the voltammetric method described in literature. No statistically significant difference was found.