Himani Agrawal

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 r(2)=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.

HPTLC method for determination of nevirapine in pharmaceutical dosage form.

A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of nevirapine both as a bulk drug and in formulations was developed and validated. The solvent system consisted of toluene-carbon tetrachloride-methanol-acetone-ammonia (3.5:3.5:2.0:1.0:0.05, v/v/v/v/v). Densitometric analysis of nevirapine was carried out in the absorbance mode at 289nm. This system was found to give compact spots for nevirapine (R(f) value of 0.44+/-0.02). Nevirapine was subjected to acid and alkali hydrolysis, oxidation, dry heat and wet heat treatment and photodegradation. The drug undergoes degradation under acidic, basic conditions and oxidation. 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 30-1000ng/spot with significantly high value of correlation coefficient. The linear regression analysis data for the calibration plots showed good linear relationship with r(2)=0.998+/-0.002 in the working concentration range of 300ng/spot to 1000ng/spot. The mean value of slope and intercept were 0.073+/-0.005 and 36.78+/-1.50, respectively. The method was validated for precision, robustness and recovery. The limit of detection and quantitation were 5 and 10ng/spot, 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.

Stability indicating HPTLC determination of linezolid as bulk drug and in pharmaceutical dosage form.

Abstract A simple, selective, precise, and stability-indicating high-performance thin layer chromatographic method of analysis of Linezolid 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 toluene–acetone (5:5, v/v). This system was found to give compact spots for Linezolid (Rf value of 0.29 ± 0.01). Linezolid was subjected to acidic, alkali hydrolysis, oxidation, and photodegradation. The degraded products also were well separated from the pure drug. Densitometric analysis of Linezolid was conducted in the absorbance mode at 254 nm. The linear regression data for the calibration plots showed good linear relationship with r2 = 0.997 ± 0.001 in the concentration range of 300–800 ng/spot. The mean value of correlation coefficient, slope, and intercept were 0.998 ± 0.003, 0.15 ± 0.009, and 19.52 ± 1.66 respectively. The method was validated for precision, accuracy, ruggedness, and recovery. The limits of detection and quantification were 20 ng/spot and 50 ng/spot, respectively. The drug undergoes degradation under acidic and basic conditions, oxidation and photo degradation. All the peaks of degraded product were resolved from the standard drug with significantly different Rf values. This indicates that the drug is susceptible to acid–base hydrolysis, oxidation, and photo degradation. Statistical analysis proves that the method is reproducible and selective for the estimation of the said drug. Because the method could effectively separate the drug from its degradation products, it can be used as a stability indicating one.

Stability-indicating HPTLC determination of tizanidine hydrochloride in bulk drug and pharmaceutical formulations

A simple, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of tizanidine hydrochloride 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-acetone-ammonia (5:5:0.1, v/v/v). This system was found to give compact spots for tizanidine hydrochloride (R(f) value of 0.32+/-0.01). Tizanidine hydrochloride was subjected to acid and alkali hydrolysis, oxidation and photodegradation. Also, the degraded product was well separated from the pure drug. Densitometric analysis of tizanidine hydrochloride was carried out in the absorbance mode at 315 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r(2)=0.9922 in the concentration range 300-1000 ng per spot. The mean value of correlation coefficient, slope and intercept were 0.9922+/-0.002, 0.064+/-0.001 and 38.09+/-1.71, respectively. The method was validated for precision, recovery and robustness. The limits of detection and quantitation were 88 and 265 ng per spot, respectively. The drug does not undergo degradation under acidic and basic conditions. The samples degraded with hydrogen peroxide showed additional peak at R(f) value of 0.12. This indicates that the drug is susceptible to oxidation. Statistical analysis proves that the method is repeatable and selective for the estimation of said drug. As the method could effectively separate the drug from its degradation product, it can be employed as a stability-indicating one.

Stability-indicating high-performance thin-layer chromatographic determination of zidovudine as the bulk drug and in pharmaceutical dosage forms

A sensitive, selective, precise, and stability-indicating high-performance thin-layer chromatographic method has been established and validated for analysis of zidovudine both as the bulk drug and in formulations. The method employs aluminum-backed silica gel 60F254 HPTLC plates with toluene-carbon tetrachloride-metha-nol-acetone, 3.5 + 3.5 + 2.0 + 1.0 (v/v), as mobile phase. This system was found to give compact spots (RF 0.41 ± 0.02) for zidovudine. Densitometric analysis of zidovudine was performed in absorbance mode at λ = 270 nm. Response was linearly dependent on amount of zidovudine in the range 100-6000 ng per spot with a significantly high correlation coefficient (r2 = 0.998 ± 0.53). Linear regression analysis data for the calibration plots showed there was a good linear relationship with r2 = 0.998 ± 0.0003 in the working concentration range 100 to 1000 ng per spot. The mean values of the slope and intercept were 0.063 ± 0.004 and 39.61 ± 1.09, respectively. The method was validated for precision, robustness, and recovery. The limits of detection and quantitation were, respectively, 20 and 40 ng per spot. Statistical analysis proved the method was repeat-able and selective for estimation of the drug. Zidovudine was subjected to acid and alkaline hydrolysis, to oxidation, to dry and wet heat treatment, and to photodegradation; it was found to undergo degradation under all these conditions except dry heat treatment. The degradation products were well separated from the pure drug with significantly different RF values. Because the method can effectively separate the drug from its degradation products, it can be employed for stability-indicating analysis. The proposed HPTLC method was used to investigate the kinetics of acid degradation. An Arrhenius plot was constructed and the activation energy was calculated.