The ICH guidance in practice: stress degradation studies on stavudine and development of a validated specific stability-indicating HPTLC assay method

A sensitive, selective, precise, and stability-indicating high-performance thin-layer chromatographic (HPTLC) method for the analysis of stavudine both as a bulk drug and in formulations is developed and validated. The solvent system consisted of toluene-methanol-chloroform-acetone (7.0:3.0:1.0:1.0, v/v/v/v). Densitometric analysis of stavudine is carried out in the absorbance mode at 270 nm. This system is found to give compact spots for stavudine (retention factor value of 0.45 +/- 0.05) following development of chromatoplates with the mobile phase. Stavudine is subjected to acid and alkali hydrolysis, oxidation, dry-heat and wet-heat treatment, and photo and UV degradation. The drug undergoes degradation under acidic and basic conditions, oxidation, and wet-heat degradation. Linearity is found to be in the range of 30-1000 ng/spot with a significantly high value of correlation coefficient. The linear regression analysis data for the calibration plots show a good linear relationship with r2 = 0.9997 +/- 0.05 in the working concentration range of 300 to 1000 ng/spot. The mean value of slope and intercept are 0.10 +/- 0.06 and 22.12 +/- 1.08, respectively. The method is validated for precision, robustness, and recovery. The limits of detection and quantitation are 10 and 30 ng/spot, respectively. The proposed HPTLC method is utilized to investigate the kinetics of the acid degradation process. Arrhenius plot is constructed and activation energy is calculated.     

Stability indicating HPTLC determination of clopidogrel bisulphate as bulk drug and in pharmaceutical dosage form

A sensitive, selective, precise and stability indicating high-performance thin layer chromatographic method of analysis of clopidogrel bisulphate both as a bulk drug and in formulations was developed and validated in pharmaceutical dosage form. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of carbon tetrachloride-chloroform-acetone (6:4:0.15, v/v/v). This system was found to give compact spots for clopidogrel bisulphate (R_f value of 0.30±0.01). Clopidogrel bisulphate was subjected to acid and alkali hydrolysis, oxidation, photodegradation and dry heat treatment. Also the degraded products were well separated from the pure drug. Densitometric analysis of clopidogrel bisulphate was carried out in the absorbance mode at 230 nm. The linear regression data for the calibration plots showed good linear relationship with r²=0.999±0.001 in the concentration range of 200-1000 ng. The mean value of correlation coefficient, slope and intercept were 0.999±0.001, 0.093±0.011 and 8.83±0.99, respectively. The method was validated for precision, accuracy, ruggedness and recovery. The limits of detection and quantitation were 40 and 120 ng per spot, respectively. The drug undergoes degradation under acidic and basic conditions, oxidation and dry heat treatment. All the peaks of degraded product were resolved from the standard drug with significantly different R_f values. This indicates that the drug is susceptible to acid-base hydrolysis, oxidation and dry heat degradation. Statistical analysis proves that the method is reproducible and selective for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating one.     

Stability indicating high-performance thin-layer chromatographic determination of nelfinavir mesylate as bulk drug and in pharmaceutical dosage form

A sensitive, selective, precise and stability indicating high-performance thin-layer chromatographic method of analysis of nelfinavir mesylate both as a bulk drug and in formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of toluene-methanol-acetone (7:1.5:1.5, v/v/v). This system was found to give compact spots for nelfinavir mesylate (R_f value of 0.45±0.02). Nelfinavir mesylate was subjected to acid and alkali hydrolysis, oxidation, dry heat treatment and photodegradation. Also the peaks of degraded products were well resolved from the pure drug with significantly different R_f values. Densitometric analysis of nelfinavir mesylate was carried out in the absorbance mode at 250 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r²=0.999±0.002 in the concentration range of 1000-6000 ng per spot. The mean value of correlation coefficient, slope and intercept were 0.999±0.002, 0.014±0.001 and 21.73±1.26, respectively. The method was validated for precision, robustness and recovery. The limits of detection and quantitation were 60 and 140 ng per spot, respectively. Statistical analysis proves that the method is repeatable and selective for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating one.     

The International Conference on Harmonisation Guidance in Practice: Stress Degradation Studies on Lamivudine and Development of a Validated Specific Stability-Indicating HPTLC Assay Method

A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of lamivudine both as a bulk drug and in formulations was developed and validated. The solvent system consisted of carbon tetrachloride – methanol – chloroform - acetonitrile (7.0: 3.0: 2.0: 1.5, v/v/v/v). Densitometric analysis of lamivudine was carried out in the absorbance mode at 275 nm. This system was found to give compact spots for lamivudine (R_F value of 0.36 ± 0.02) following double development of chromatoplates with the same mobile phase. Lamivudine was subjected to acid and alkali hydrolysis, oxidation, dry heat and wet heat treatment and photo degradation. The drug undergoes degradation under acidic, basic conditions, oxidation, wet heat and photo degradation. Also the degraded products were well resolved from the pure drug with significantly different R_F values. Linearity was found to be in the range of 50 – 1000 ng spot^–1 with significantly high value of correlation coefficient. The linear regression analysis data for the calibration plots showed good linear relationship with r² = 0.9994 ± 0.05 in the working concentration range of 300 ng spot^–1 to 1000 ng spot^–1. The mean value of slope and intercept were 0.11 ± 0.08 and 10.47 ± 1.21, respectively. The method was validated for precision, robustness and recovery. The limit of detection and quantitation were 15 ng spot^–1 and 40 ng spot^–1 respectively. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating one. Moreover, the proposed HPTLC method was utilized to investigate the kinetics of acid degradation process. Arrhenius plot was constructed and activation energy was calculated.     

A Validated Stability-Indicating TLC Method for Determination of Forskolin in Crude Drug and Pharmaceutical Dosage Form

A simple, accurate, selective, precise, economical and stability-indicating high-performance thin-layer chromatographic method for analysis of forskolin in crude drug and in pharmaceutical dosage form was developed and validated. The method was developed on TLC aluminium plates precoated with silica gel 60F-254 using solvent system benzene:methanol (9:1, v/v), which gives compact spot of forskolin (R _f value 0.25 ± 0.02). Densitometric analysis of forskolin was carried out in the absorbance mode at 545 nm after spraying with anisaldehyde sulphuric acid. The linear regression analysis data for the calibration plots showed good linear relationship with r = 0.994 and 0.994 with respect to peak height and peak area, respectively, in the concentration range 100–1,000 ng per spot. The limits of detection and quantification were 8.1 and 26.9 ng per spot, respectively. The proposed method was applied for determination of forskolin in Coleus forskohlii root and in capsule dosage forms, which showed 0.18 and 0.57% w/w of forskolin. Forskolin was subjected to acid and alkali hydrolysis, oxidation, photodegradation and heat degradation. It was observed that the drug is susceptible to acid, base hydrolysis, oxidation, photo-oxidation and heat degradation. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of forskolin in crude drug and in pharmaceutical dosage forms. The developed method effectively resolved the forskolin from components of C. forskohlii root, from excipients of capsule as well as the degradation products of forskolin hence, it can be employed for routine analysis and as a stability-indicating method.     

Stability-indicating high performance thin layer chromatographic determination of sulfanilamide in human urine

A simple, sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic (HPTLC) method was developed and applied to human urine for the densitometric determination of sulfanilamide. A mixture of chloroform-ethyl acetate-xylene (2.5: 4.0: 1.0, v/v/v) was used as a mobile phase. The system was found to give compact spots for sulfanilamide (retardation factor, R _f = 0.21±0.02). The linear regression analysis data for the calibration plots showed good linear relationship with r ² = 0.9970 ± 0.0003 and r ² = 0.9947 ± 0.020 within the concentration range of 50–250 ng per spot and 100–1000 ng per spot with respect to peak area, respectively. The limit of detection (LOD) and quantification (LOQ) were 8 and 25 ng per spot, respectively. Sulfanilamide was subjected to acid and alkali hydrolysis, oxidation, dry heat and wet heat treatment. According to the International Conference on Harmonization (ICH) guidelines the method was validated for precision, recovery and robustness. The ultraviolet (UV) spectra of the degradation products which had different spectra from sulfanilamide were also recorded. The article is published in the original.     

Stability-indicating high performance thin layer chromatography determination of Paroxetine hydrochloride in bulk drug and pharmaceutical formulations

A simple selective precise and stability-indicating high performance thin layer chromatographic method of analysis of Paroxetine hydrochloride both as a bulk drug and in formulations was developed and validated. The method employed TLC (Thin Layer Chromatography) aluminum precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of butanol:acetic acid:water (8:2:0.5, v/v/v). This system was found to give compact spots for Paroxetine HCl (Rf, retardation factor, value-0.48 ± 0.02). Paroxteine HCl was subjected to acid and alkali hydrolysis, oxidation and photodegradation, where the degraded product was well separated from the pure drug. Densitometric analysis of Paroxetine hydrochloride was carried out in the absorbance mode at 295 nm. The linear regression analysis data for the calibration spots showed good relationship with (regression) r² = 0.9903 in the amount range of 300-1500 ng (nanogram) per spot. The mean value of co-relation co-efficient, slope and intercept were 0.9903 ± 0.001, 5.38 ± 0.058 and 182.5 ± 2.16 respectively. The method was validated for precision, recovery and robustness. The limits of detection and quantitation were 50 and 150 ng, respectively. The drug doesnot undergo degradation with oxidation, but gets affected in acidic and alkaline conditions. The acid and alkali degradation showed extra peaks at 0.4 and 0.08 Rf, respectively. This indicates that the drug is susceptible to acidic and alkaline medium. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one.     

Stability-Indicating TLC Method for the Determination of Dutasteride in Pharmaceutical Dosage Forms

A simple, sensitive, selective, precise and stability-indicating thin-layer chromatographic method for determination of dutasteride both as a bulk drug and as pharmaceutical tablets was developed and validated as per the International Conference on Harmonization guidelines. The method employed thin-layer chromatography aluminium plates precoated with silica gel 60F₂₅₄ as the stationary phase and the mobile phase consisted of acetonitrile:methanol:dichloromethane in the ratio of 2.0:1.0:2.0, v/v/v. This solvent system was found to give compact spots for dutasteride (R _f value of 0.64 ± 0.02). Densitometric analysis of dutasteride was carried out in the absorbance mode at 244 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r = 0.9943 with respect to peak area in the concentration range of 100–600 ng per band. The method was validated for precision, accuracy, ruggedness and recovery. The limits of detection and quantitation were 7.54 and 22.85 ng per band, respectively. Dutasteride was subjected to acid and alkali hydrolysis, oxidation, photo degradation, dry heat and wet heat treatment. The drug undergoes degradation under acidic, basic conditions, photolytic, oxidative and upon wet and dry heat treatment. The degraded products were well separated from the pure drug. The statistical analysis proves that the developed method for quantification of dutasteride as bulk drug and from pharmaceutical tablets is reproducible and selective. As the method could effectively separate the drug from its degradation products, it can be employed as stability-indicating.     

Stability indicating reversed-phase high-performance liquid chromatographic and thin layer densitometric methods for the determination of ziprasidone in bulk powder and in pharmaceutical formulations

Two sensitive and reproducible methods were developed and validated for the determination of ziprasidone (ZIP) in the presence of its degradation products in pure form and in pharmaceutical formulations. The fi rst method was based on reversed-phase high-performance liquid chromatography (HPLC), on a Lichrosorb RP C(18) column using water:acetonitrile:phosphoric acid (76:24:0.5 v/v/v) as the mobile phase at a fl ow rate of 1.5 mL min(-1) at ambient temperature. Quantification was achieved with UV detection at 229 nm over a concentration range of 10-500 micro g mL(-1) with mean percentage recovery of 99.71 +/- 0.55. The method retained its accuracy in presence of up to 90% of ZIP degradation products. The second method was based on TLC separation of ZIP from its degradation products followed by densitometric measurement of the intact drug spot at 247 nm. The separation was carried out on aluminium sheet of silica gel 60 F(254) using choloroform:methanol:glacial acetic acid (75:5:4.5 v/v/v) as the mobile phase, over a concentration range of 1-10 micro g per spot and mean percentage recovery of 99.26 +/- 0.39. Both methods were applied successfully to laboratory prepared mixtures and pharmaceutical capsules.     

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.     

Stress degradation studies and development of stability-indicating TLC-densitometry method for determination of prednisolone acetate and chloramphenicol in their individual and combined pharmaceutical formulations

ABSTRACT: A rapid and reproducible stability indicating TLC method was developed for the determination of prednisolone acetate and chloramphenicol in presence of their degraded products. Uniform degradation conditions were maintained by refluxing sixteen reaction mixtures for two hours at 80°C using parallel synthesizer including acidic, alkaline and neutral hydrolysis, oxidation and wet heating degradation. Oxidation at room temperature, photochemical and dry heating degradation studies were also carried out. Separation was done on TLC glass plates, pre-coated with silica gel 60F-254 using chloroform: methanol (14:1 v/v). Spots at Rf 0.21 ± 0.02 and Rf 0.41 ± 0.03 were recognized as chloramphenicol and prednisolone acetate, respectively. Quantitative analysis was done through densitometric measurements at multiwavelength (243 nm, λmax of prednisolone acetate and 278 nm, λmax of chloramphenicol), simultaneously. The developed method was optimized and validated as per ICH guidelines. Method was found linear over the concentration range of 200-6000 ng/spot with the correlation coefficient (r2 ± S.D.) of 0.9976 ± 3.5 and 0.9920 ± 2.5 for prednisolone acetate and chloramphenicol, respectively. The developed TLC method can be applied for routine analysis of prednisolone acetate and chloramphenicol in presence of their degraded products in their individual and combined pharmaceutical formulations.     

Effective separation and simultaneous analysis of anabolic androgenic steroids (AAS) in their pharmaceutical formulations by a validated TLC-densitometry method

ABSTRACT: A TLC densitometric method was developed for simultaneous determination of four anabolic androgenic steroids (AAS) of testosterone derivatives including testosterone propionate (TP), testosterone phenyl propionate (TPP), testosterone isocaproate (TI) and testosterone deaconate (TD) in their pharmaceutical products. Separation was carried out on Al based TLC plates, pre-coated with silica gel 60F-254 using hexane and ethyl acetate (8.5:1.5, v/v). Spots at Rf 0.31+/-0.01, 0.34+/-0.01, 0.40+/-0.01 and 0.45+/-0.02 were recognized as TPP, TP, TI and TD, respectively. Quantitative analysis was done by densitometric measurements at lambdamax 251 nm for all derivatives. The developed method was validated as per ICH guidelines. Method was found linear over the concentration range of 200-1200 ng/spot with the correlation coefficient of 0.995, 0.993, 0.995 and 0.996 for TP, TPP, TI, TD, respectively. Limit of detection for all derivatives were in the range of 16.7-22.3 ng/spot while limit of quantitation were found to be in the range of 55.7-70.9 ng/spot. The developed TLC method can be applied for the simultaneous routine analysis of testosterone derivatives in their individual and combined pharmaceutical formulations.     

Development and validation of a stability-indicating RP-HPLC method for determination of atomoxetine hydrochloride in tablets

This paper describes the development of a stability-indicating RP-HPLC method for the determination of atomoxetine hydrochloride (ATX) in the presence of its degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of acid, base, oxidation, wet heat, dry heat, and photodegradation. In stability tests, the drug was susceptible to acid, base, oxidation, and dry and wet heat degradation. It was found to be stable under the photolytic conditions tested. The drug was successfully separated from the degradation products formed under stress conditions on a Phenomenex C18 column (250 x 4.6 mm id, 5 microm particle size) by using acetonitrile-methanol-0.032 M ammonium acetate (55 + 05 + 40, v/v/v) as the mobile phase at 1.0 mL/min and 40 degrees C. Photodiode array detection at 275 nm was used for quantitation after RP-HPLC over the concentration range of 0.5-5 microg/mL with a mean recovery of 100.8 +/- 0.4% for ATX. Statistical analysis demonstrated that the method is repeatable, specific, and accurate for the estimation of ATX. Because the method effectively separates the drug from its degradation products, it can be used as a stability-indicating method.     

HPLC determination of diltiazem in human plasma and its application to pharmacokinetics in humans

A simple and sensitive reversed-phase high performance liquid chromatographic method (HPLC) has been developed and validated for the routine analysis of diltiazem in human plasma and the study of the pharmacokinetics of the drug in the human body. Diltiazem and diazepa (internal standard) were extracted with a mixed organic solution of hexane, chloroform and isopropanol (60:40:5, v/v/v), and then HPLC separation of the drugs was performed on an Spherisorb C(18) column and detected by ultraviolet absorbance at 239 nm. The use of methanol-water solution (containing 2.8 mm triethylamine, 80:20, v/v) as the mobile phase at a fl ow-rate of 1.2 mL/min enables the baseline separation of the drugs free from interferences with isocratic elution. The method was linear in the clinical range 0-300 ng/mL and the lower limit of detection of diltiazem in plasma was 3 ng/mL. The range of percentage of relative standard deviation (%RSD) was from 3.5 to 6.8% for within-day analyses and from 6.2 to 8.4% for between-day analyses, respectively. The extraction recoveries of diltiazem from spiked human plasma (n = 5) at three concentrations were 91.4-104.0%. The method has been used to determine diltiazem in human plasma samples from eight volunteers who had taken diltiazem hydrochloride slow release tables and the data obtained was fitted with a program on computer to study the pharmacokinetics. The results showed that the peak level in plasma approximately averaged 118.5 +/- 14.3 ng/mL at 3.1 +/- 0.4 h, and the areas under the drug concentration curves (AUC) was 793.1 +/- 83.1 ng.h/mL.     

HPTLC determination of rabeprazole and domperidone in capsules and its validation

This paper describes a validated high-performance thin-layer chromatography (HPTLC) method for simultaneous estimation of rabeprazole (RA) and domperidone (DO) in pure powder and in capsule formulations. An HPTLC method separation is achieved on an aluminum sheet of silica gel 60F(254) using ethyl acetate-methanol-benzene-acetonitrile (30:20:30:20 v/v) as mobile phase. Quantitation is achieved with UV detection at 287 nm over a concentration range of 400-1200 ng/spot and 600-1800 ng/spot with mean recovery of 99.82 +/- 0.74 and 99.43 +/- 0.68 for RA and DO, respectively, in the HPTLC method. This method is simple, precise, and sensitive, and it is applicable for the simultaneous determination of RA and DO in pure powder and in capsule formulation.     

Stability-indicating thin-layer chromatographic method for quantitative determination of ribavirin

A simple and accurate stability-indicating thin-layer chromatographic (TLC) method is developed and validated for the quantitative determination of ribavirin (RBV) in its bulk and with used for development consists of chloroform-methanol-acetic acid (60:15:15, v/v/v). The separated spots are visualized as bluish green spots after being sprayed with anisaldehyde reagent. RBV is subjected to different accelerated stress conditions. The drug is found to undergo degradation under all stress conditions, and the degradation products are well resolved from the pure drug with significantly different Rf values. The optical densities of the separated spots are found to be linear with the amount of RBV in the range of 5-40 microg/spot with a good correlation coefficient (r=0.9980). The limit of detection and limit of quantitation values are 1.40 and 4.67 microg/spot, respectively. Statistical analysis proves that the method is repeatable and accurate for the determination of RBV in the presence of its degradation products. The method meets the International Conference on Harmonisation/Food and Drug Administration regulatory requirements. The proposed TLC method is successfully applied for the determination of RBV, pure and in capsules, with good accuracy and precision; the label claim percentages are 98.8%+/-1.5%. The results obtained by the proposed TLC method are comparable with those obtained by the official method.     

Stability-indicating chromatographic methods for the determination of some oxicams

Two sensitive and selective methods were developed for the determination of some oxicams, namely, lornoxicam (LOX), tenoxicam (TEX), and meloxicam (MEX), in the presence of their alkaline degradation products. The first method is based on the thin-layer chromatographic separation of the 3 drugs from their alkaline degradation products, followed by densitometric measurement of the intact drug spots for LOX, TEX, and MEX at 380, 370, and 364 nm, respectively. The developing systems used for separation are ethyl acetate-methanol-26% ammonia (17 + 3 + 0.35, v/v/v) for LOX and TEX and chloroform-n-hexane-96.0% acetic acid (18 + 1 + 1, v/v/v) for MEX. The linear ranges were 0.25-6.0 microg/spot for LOX and TEX and 0.5-10 microg/spot for MEX, with mean recoveries of 99.80 +/- 1.32, 100.57 +/- 1.34, and 100.71 +/- 1.57%, respectively. The second method is based on the liquid chromatographic separation of the 3 drugs from their alkaline degradation products on a reversed-phase C18 column, using mobile phases of methanol-acetonitrile-acetate buffer, pH 4.6 (4.5 + 0.5 + 5.0, v/v/v) for LOX and MEX and methanol-acetonitrile-acetate buffer, pH 4.6 (1.9 + 0.1 + 3.0, v/v/v) for TEX at ambient temperature. Quantification is achieved by UV detection at 280 nm, based on peak area. The linear ranges were 0.5-20 microg/mL for LOX and TEX and 1.25-50 microg/mL for MEX, with mean recoveries of 99.81 +/- 1.01, 98.90 +/- 1.61, and 100.86 +/- 1.55%, respectively. The methods were validated according to guidelines of the International Conference on Harmonization. The developed methods were successfully applied to the determination of LOX, TEX, and MEX in bulk powder, laboratory-prepared mixtures containing different percentages of degradation products, and pharmaceutical dosage forms.     

Development and validation of a stability-indicating method for determination of free sterols in the Asian medicinal leech Hirudo manillensis

A rapid, simple, sensitive, selective, precise and robust thin-layer chromatography densitometric method for the determination of free sterols in leech was developed and validated on silica gel layer using carbon tetrachloride-methanol-formic acid (9.5:1.5:0.55, v/v/v). Spectrodensitometric scanning was carried using a Camag TLC scanner III at 366 nm after spraying 2% methanolic sulphuric acid, which gave compact spots for cholesterol (R(F) = 0.35 ± 0.02). The regression analysis data for calibration plot implied a good linear relationship (r(2) = 0.99958) between response and concentration over the range 100-600 ng per spot with respect to peak area. The limits of detection and quantification were found to be 13.8 ± 0.51 and 45.01 ± 1.29 ng per spot, respectively. Validation was in accordance to the International Conference on Harmonization guidelines. Cholesterol was subjected to forced stress conditions of oxidation, hydrolysis and heat. Degradation products resulting from the forced stress did not interfere with detection because the degradant peaks were well separated from the cholesterol peak. The densitometric method can be regarded as stability-indicating and can be used for quality control assay of cholesterol in leech extract.     

HPTLC densitometric analysis of arbutin in bulk drug and methanolic extracts of Arctostaphylos uva-ursi

A high-performance thin layer chromatographic densitometric method for the analysis of arbutin was developed and validated in the present investigation. Arbutin was separated on aluminium-backed silica gel 60 F(254) plates with methanol?:?chloroform (3:7)% (v/v) as the mobile phase. This system was found to give a compact spot of arbutin at a retention factor (R(f)) value of 0.32 ± 0.02. The limit of detection and limit of quantification were found to be 35.42 and 106.26 ng/spot, respectively. The proposed method with a high degree of precision and accuracy was employed for the analysis of arbutin in the bulk drug and methanolic extract of Arctostaphylos uva-ursi.     

Development and validation of stability indicating analytical method for Ilaprazole

The objective of the present study was to develop and validate a rapid and simple stability indicating analytical method for estimating Ilaprazole. Ilaprazole was subjected to different stress conditions prescribed by International Conference on Harmonization (ICH) such as hydrolysis, oxidation, photolytic and dry heat degradation conditions. The drug was very susceptible to degradation under hydrolysis and photolytic conditions, less susceptible to oxidation and stable under dry heat degradation condition. An acceptable separation of drug and its degradants was achieved by using a C-18 column and mobile phase composed of ammonium acetate buffer (pH 3.2)—acetonitrile (55: 45, v/v). Flow rate was 1 mL/min and detection wavelength was set at 303 nm. Retention time of drug was found to be 6.6 min and analysis can be completed within 10 min. The method was validated with respect to linearity, precision, accuracy, robustness, LOD and LOQ as per ICH. The method was linear (R² = 0.996) in the range of 2.5–250 μg/mL. The recovery was in the range from 99.2–100.2%.