Determination of gatifloxacin and ornidazole in tablet dosage forms by high-performance thin-layer chromatography.

A simple and sensitive high-performance thin-layer chromatography (HPTLC) method has been developed for the quantitative estimation of gatifloxacin and ornidazole in its combined dosage forms. Gatifloxacin and ornidazole were chromatographed on silica Gel 60 F(254) TLC plate using n-butanol:methanol:ammonia (6 M) (8:1:1.5 v/v) as the mobile phase and scanned at 302 nm using a Camag TLC Scanner 3. The R(f) value of gatifloxacin and ornidazole was found to be 0.21 +/- 0.02 and 0.76 +/- 0.04, respectively. The linearity of gatifloxacin and ornidazole were in the range of 100 - 500 ng/spot and 250 - 1250 ng/spot, respectively. The limit of detection was found to be 40 ng/spot for gatifloxacin and 100 ng/spot for ornidazole. The proposed method was applied for the determination of gatifloxacin and ornidazole in combined dosage forms.     

Simultaneous determination of atorvastatin calcium and ramipril in capsule dosage forms by high-performance liquid chromatography and high-performance thin layer chromatography

Two simple and accurate methods to determine atorvastatin calcium and ramipril in capsule dosage forms were developed and validated using HPLC and HPTLC. The HPLC separation was achieved on a Phenomenex Luna C18 column (250 x 4.6 mm id, 5 microm) in the isocratic mode using 0.1% phosphoric acid-acetonitrile (38 + 62, v/v), pH 3.5 +/- 0.05, mobile phase at a flow rate of 1 ml/min. The retention times were 6.42 and 2.86 min for atorvastatin calcium and ramipril, respectively. Quantification was achieved with a photodiode array detector set at 210 nm over the concentration range of 0.5-5 microg/mL for each, with mean recoveries (at three concentration levels) of 100.06 +/- 0.49% and 99.95 +/- 0.63% RSD for atorvastatin calcium and ramipril, respectively. The HPTLC separation was achieved on silica gel 60 F254 HPTLC plates using methanol-benzene-glacial acetic acid (19.6 + 80.0 + 0.4, v/v/v) as the mobile phase. The Rf values were 0.40 and 0.20 for atorvastatin calcium and ramipril, respectively. Quantification was achieved with UV densitometry at 210 nm over the concentration range of 50-500 ng/spot for each, with mean recoveries (at three concentration levels) of 99.98 +/- 0.75% and 99.87 +/- 0.83% RSD for atorvastatin calcium and ramipril, respectively. Both methods were validated according to International Conference on Harmonization guidelines and found to be simple, specific, accurate, precise, and robust. The mean assay percentages for atorvastatin calcium and ramipril were 99.90 and 99.55% for HPLC and 99.91 and 99.47% for HPTLC, respectively. The methods were successfully applied for the determination of atorvastatin calcium and ramipril in capsule dosage forms without any interference from common excipients.     

Estimation of trans-resveratrol in herbal extracts and dosage forms by high-performance thin-layer chromatography

A simple, sensitive and precise high-performance thin-layer chromatographic (HPTLC) method of analysis of trans-resveratrol in Polygonum cuspidatum root extracts and in dosage forms was developed and validated. The separation was carried out on a TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase, eluted with chloroform-ethylacetate-formic acid (2.5 : 1 : 0.1) as mobile phase. Densitometric analysis of trans-resveratrol was carried out in the absorbance mode at 313 nm. This system was found to give compact spot for trans-resveratrol (Rf value of 0.40+/-0.03). A good linear regression relationship between peak areas and the concentrations was obtained over the range of 0.5-3.0 microg/spot with correlation coefficient 0.9989. The limit of detection and quantification was found to be 9 and 27 ng/spot. The method was validated for precision and recovery. The spike recoveries were within 99.85 to 100.70%. The RSD values of the precision in the range 0.37-1.84%. The proposed developed HPTLC method can be applied for identification and quantitative determination of trans-resveratrol in herbal extracts and dosage forms.     

Simultaneous quantitative determination of amiloride hydrochloride and hydrochlorothiazide in tablets by high-performance liquid chromatography

Summary A procedure for the simultaneous quantitative determination of amiloride hydrochloride and hydrochlorothiazide by high-performance liquid chromatography is proposed. A reversed-phase LiChrosorb C8 stationary phase is used. The eluent consisted of an acetonitrile/0.1M phosphate buffer pH3 (15∶85) mixture, containing 50mM propylamine hydrochloride. In this system amiloride hydrochloride, a basic drug, eluted with a acceptable asymmetry factor (Asf=2.1). A simple extraction procedure with methanol is used. Relative standard deviations of 0.87% and 1.6% were obtained for amiloride hydrochloride and hydrochlorothiazide respectively. Chlorothiazide, a thiazide diuretic, is a suitable internal standard. Furthermore the method is also specific for other thiazide diuretics, potassium-sparing diuretics and loop diuretics and for the respective hydrolysis productes of both drugs. Analysis time is reduced to a minimum; the chromatographic separation is complete within 6 minutes.     

Simultaneous determination of hydrochlorothiazide and losartan potassium in tablets by high-performance low-pressure chromatography using a multi-syringe burette coupled to a monolithic column

This contribution describes use of a separation method based on on-line coupling of a multisyringe flow system with a chromatographic monolithic column for simultaneous determination of hydrochlorothiazide and losartan potassium in tablets. The system comprised a multisyringe module, three low-pressure solenoid valves, a monolithic C₁₈ column (25 mm × 4.6 mm i.d.), and a diode-array detector. The mobile phase was 10 mmol L⁻¹ potassium dihydrogen phosphate (pH 3.1)-acetonitrile-methanol (65:33:2 v/v/v) at a flow rate 0.8 mL min⁻¹. UV detection was carried out at 226 nm. The multi-syringe chromatographic (MSC) method with UV spectrophotometric detection was optimized and validated. Results from validation were very good. The analysis time was about 400 s. The method was found to be applicable to routine analysis of both compounds in tablets. The coupling of the monolithic columns with a multi-syringe flow-injection analysis manifold provides an excellent and inexpensive tool to solve the separation problems without use of HPLC instrumentation.     

Simultaneous determination of bergenin and gallic acid in Bergenia ligulata wall by high-performance thin-layer chromatography

A simple and reproducible high-performance thin-layer chromatographic method was developed for the simultaneous determination of bergenin and gallic acid in Bergenia ligulata. Water and methanol were used as the extracting solvents. The concentrations of bergenin and gallic acid in both of these solvents were found to be almost the same. The method involves separation of the components by thin-layer chromatography on a precoated Silica Gel 60 F254 plate with a solvent system of ethyl acetate-formic acid-acetic acid-water (100 + 11 + 11 + 27). The sensitivity of the method for bergenin was 0.30 microg, whereas for gallic acid it was 0.25 microg. The proposed method is precise and sensitive and can be used for the detection, monitoring, and simultaneous quantification of bergenin and gallic acid in B. ligulata.     

Determination of rosuvastatin and ezetimibe in a combined tablet dosage form using high-performance column liquid chromatography and high-performance thin-layer chromatography

This paper describes validated HPLC and HPTLC methods for the simultaneous determination of rosuvastatin (ROS) and ezetimibe (EZE) in a combined tablet dosage form. The isocratic RP-HPLC analysis was performed on a Chromolith C18 column (100 x 6 mm id) using 0.1% (v/v) orthophosphoric acid solution (pH 3.5)-acetonitrile (63 + 37, v/v) mobile phase at a flow rate of 1 mL/min at ambient temperature. Quantification was carried out using a photodiode array UV detector at 245 nm over the concentration range of 0.5-10 microg/mL for ROS and EZE. The HPTLC separation was carried out on an aluminum-backed sheet of silica gel 60F(254) layers using n-butyl acetate-chloroform-glacial acetic acid (1 + 8 + 1, v/v/v) mobile phase. Quantification was achieved with UV densitometry at 245 nm over a concentration range of 0.1-0.9 micro/spot for ROS and EZE. The analytical methods were validated according to International Conference on Harmonization guidelines. Low RSD values indicated good precision. Both methods were successfully applied for the analysis of the drugs in laboratory-prepared mixtures and commercial tablets. No chromatographic interference from the tablet excipients was found. These methods are simple, precise, and sensitive, and are applicable for simultaneous determination of ROS and EZE in pure powder and tablets.     

A comparative study of first-derivative spectrophotometry and high-performance liquid chromatography applied to the determination of losartan potassium in tablets

Losartan, a highly effective blood pressure-lowering agent, has been widely used for the treatment of hypertension. A fast and reliable method for the determination of losartan was highly desirable to support formulation screening and quality control. A first-derivative UV spectroscopic method and HPLC were developed for the determination of losartan in the tablet dosage form. The first-derivative spectrum recorded between 220 and 320 nm and a zero-crossing technique for first-derivative measurement at 232.5 nm were selected. The selectivity and sensitivity of the method was in desirable range. In comparison with the direct UV method, first-derivative UV spectroscopy has a definite trough without any interference from UV absorbing-excipients. This method is also fast and economical in comparison with the more time-consuming HPLC method regularly used for formulation screening and quality control and can be used routinely by any laboratory possessing a spectrophotometer with a derivative accessory. The linear concentration ranges were 2-50 microg ml(-1), (D(1)=-0.0159C-0.0056, r=0.9994, n=6). Between-days CV of < or =2.9%, within-day CV of < or =2.1%, and analytical recovery close to 98.1% show the suitability of the method for determination in quality control.     

Stability-indicating high-performance column liquid chromatography and high-performance thin-layer chromatography methods for the determination of olopatadine hydrochloride in tablet dosage form

This paper describes two simple, specific, accurate, and precise methods for estimation of olopatadine hydrochloride (OLO) in tablet dosage form. The first method is a stability-indicating isocratic RP-HPLC method. The analysis is performed on an RP-18 column using 0.1% orthophosphoric acid (adjusted to pH 4.5 with triethylamine)-acetonitrile (75 + 25, v/v) mobile phase at a flow rate of 1 mL/min. Paracetamol (PAR) was selected as the internal standard. Retention times of OLO and PAR were 11.30 +/- 0.02 and 4.70 +/- 0.03 min, respectively. For the HPTLC method, precoated silica gel 60 F254 aluminum sheets were used as the stationary phase; the mobile phase was methanol-chloroform-ammonia (8 + 2 + 0.1, v/v/v). The detection of the analyte band was carried out at 301 nm, and its Rf value was 0.46 +/- 0.03. The analytical methods were validated according to International Conference on Harmonization guidelines. Linear regression analysis data for the calibration plots showed a good linear relationship between response and concentration in the range of 0.1-1 microg/mL and 0.1-0.9 microg/band for HPLC and HPTLC, respectively.     

Determination of methoxsalen in dosage forms by high-performance liquid chromatography

Summary A new, rapid, sensitive, and specific method for the determination of methoxsalen in dosage forms using HPLC has been developed. methoxsalen is extracted in chloroform, evaporated on a water bath, and the residue is redissolved in ethanol. A standard solution of khellin (internal standard) in ethanol is added, and injected. A plot of peak height ratio (methoxsalen/internal standard) vs. concentration of methoxsalen gave a straight line (r=0.998). The column used was a stainless steel, 3.8 mm×30 cm, and the mobile phase was methanol: water (6040) at a flow rate of 2 cm³/min. Retention times for methoxsalen and khellin were 3.45 and 9.6 min, respectively. This method was found superior to the spectrophotometric assay in that no interference was encountered from structurally similar compounds or from coloring agents used in some commercial methoxsalen products.     

Simultaneous assay of olanzapine and fluoxetine in tablets by column high-performance liquid chromatography and high-performance thin-layer chromatography

This paper describes validated high-performance liquid chromatographic (LC) and high-performance thin-layer chromatographic (TLC) methods for the simultaneous estimation of olanzapine and fluoxetine in pure powder and tablet formulations. The LC separation was achieved on a Lichrospher 100 RP-180, C18 column (250 mm, 4.0 mm id, 5 microm) using 0.05 M potassium dihydrogen phosphate buffer (pH 5.6 adjusted with o-phosphoric acid)-acetonitrile (50 + 50, v/v) as the mobile phase at a flow rate of 1 mL/min and ambient temperature. The TLC separation was achieved on aluminum sheets coated with silica gel 60F254 using methanol-toluene (40 + 20, v/v) as the mobile phase. Quantitation was achieved by measuring ultraviolet absorption at 233 nm over the concentration range of 10-70 and 40-280 microg/mL with mean recovery of 99.54 +/- 0.89 and 99.73 +/- 0.58% for olanzapine and fluoxetine, respectively, by the LC method. Quantitation was achieved by measuring ultraviolet absorption at 233 nm over the concentration range of 100-800 and 400-3200 ng/spot with mean recovery of 101.53 +/- 0.06 and 101.45 +/- 0.35% for olanzapine and fluoxetine, respectively, by the TLC method with densitometry. These methods are simple, precise, and sensitive, and they are applicable for simultaneous determination of olanzapine and fluoxetine in tablet formulations.     

Quantitative determination of beta-asarone in calamus by high-performance thin-layer chromatography

A quantitative high-performance thin-layer chromatographic method for determination of beta-asarone in Calamus rhizome was developed and validated. The method is suitable for proper identification of Acorus calamus. Through the use of caffeine-modified silica gel as the stationary phase and toluene-ethyl acetate (93 + 7, v/v) as the mobile phase, beta-asarone is baseline separated from its isomer alpha-asarone. Scanning densitometry with absorption measurement at 313 nm allows specific, accurate, and precise quantification of beta-asarone. The working range of 40 to 200 ng absolute of the target substance is sufficient to establish whether a given sample passes the limit test of 0.5% maximum as required by the Swiss Pharmacopoeia.     

Simultaneous determination of zirconium and molybdenum by first-derivative spectrophotometry.

A first-derivative spectrophotometric method for the simultaneous determination of Zr and Mo with Alizarin Red S is described. Measurements were made at the zero-crossing wavelengths at 490.5 nm for Zr and 446.0 nm for Mo. The calibration graphs were linear at 0.5-20 and 0.5-13.0 microg ml(-1) for Zr and Mo, respectively. The possible interfering effects of various ions were studied. Only iron was interfered in this system. The validity of the method was examined by using some mixtures of Mo and Zr. The method was applied in different matrix in both presence and absence of some foreign metal ions.     

Development and validation of thin-layer chromatography and high-performance thin-layer chromatography methods for the simultaneous determination of linagliptin and empagliflozin in their co-formulated dosage form

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive, simple and validated thin-layer chromatography (TLC) method (method A) and a high-performance thin-layer...     

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.     

Simultaneous determination of water-and fat-soluble vitamins by high-performance thin-layer chromatography using an aqueous micellar mobile phase

It is shown that fat-soluble vitamins A and E and water-soluble vitamins B (B₁, B₂, B₆, and B₁₂) can be separated by high-performance thin-layer chromatography using fractional elution. Benzene was used as the first mobile phase, and a 0.02 M aqueous micellar solution of sodium dodecyl sulfate was the second eluant.     

Simultaneous determination of levofloxacin hemihydrate and ambroxol hydrochloride in tablets by thin-layer chromatography combined with densitometry

This paper describes the application of thin-layer chromatography (TLC) combined with densitometry to simultaneous determination of levofloxacin hemihydrate (LEV) and ambroxol hydrochloride (AMB) in bulk and tablets. The separation was achieved on aluminum sheet of silica gel 60 F ₂₅₄ using chloroform: methanol: toluene: ammonia (10: 6: 3: 0.8 v/v/v/v) as mobile phase. Quantification was carried out densitometrically at 245 nm. This system was found to give compact spots for LEV (R _f value of 0.4) and AMB (R _f value of 0.7). The calibration curves for LEV and AMB was found to be linear between 9960–16600 ng/spot (r ² = 0.999) and 600–1000 ng/spot (r ² = 0.999), respectively. The mean percentage recoveries from tablets for LEV and AMB were 99.45% and 99.58%, respectively. The TLC-densitometry method has many advantages, such as simplicity, reasonable sensitivity, rapidity, and low cost, and it can be successfully used in routine analysis of both these drugs in tablet formulations.     

Simultaneous determination of retinol and tocopherols by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method to determine retinol and all four tocopherols (alpha-, beta-, gamma- and delta-) simultaneously was established using a reversed-phase column (YMC-PACK A-302 S-5 120A ODS). The HPLC conditions were mobile phase 65% isopropanol, sample solvent 99.5% methanol and temperature 30 degrees C. Retinol and tocopherols were measured in rat liver.