Authors:Na Zhou, Tao Li, Lianfeng Ai, Chunhai Guo, Juan Zhang, Shan Fu and Qiao Wang
also lead to the loss of drug activity and elicit possible adverse reactions. Therefore, forceddegradation studies are recognized as an important part of drug development to identify the likely degradation products, which can in turn help establish the
The objective of the present study was to report the stability of novel antiviral drug, valganciclovir based on the information obtained from forced degradation studies. Valganciclovir was subjected to forced hydrolytic (acidic, alkaline and neutral), oxidative, photolytic and thermal stress in accordance with the ICH guideline Q1A (R2). The drug showed labiality under only acidic and photoacidic conditions while it was stable to other stress conditions. Resolution of the drug and degradation products was achieved on a Hypersil Gold C-18 column (4.6 × 250 mm, 5 μm) utilizing acetonitrile (A) and potassium dihydrogen ortho phosphate buffer (pH 5.0; 0.01M) in the ratio of 5:95 (v/v) at a flow rate of 0.6 ml/min and at the detection wavelength 252 nm. The major acidic stress degradation product was characterized by LC-MS/MS and its fragmentation pathway was proposed. Validation of the LC-DAD method was carried out in accordance with ICH guideline. The method met all required criteria and was applied for analysis of commercially available tablets.
A simple, selective, and precise stability-indicating reversed-phase liquid chromatographic method was developed and validated for the determination of nilotinib. Nilotinib was subjected to acid and alkali hydrolysis, oxidation, thermal, and photo-degradation. The degradation products were well separated from the pure drug. The method was based on isocratic elution of nilotinib and its degradation products on reversed phase C18 column (100 mm × 4.6 mm, 3.5 μm) — Zorbax Eclipse Plus using a mobile phase consisting of 10 mM KH2PO4:acetonitrile (54.5:45.5%, v/v) at a flow rate of 1 mL min−1. Quantitation was achieved with UV detection at 265 nm. Linearity, accuracy and precision were found to be acceptable over the concentration range of 0.1–80 μg mL−1. The drug was found to be susceptible to acid and base hydrolysis but resistant to oxidation, dry heat degradation, and photodegradation. The proposed method was successfully applied to the determination of nilotinib in bulk and in its pharmaceutical preparation.
The objective of the present investigation was to develop and validate a stability indicating liquid chromatography (LC) method which should possess potential to separate flucloxacillin as well as all the degradation products. Simultaneously, our aim was also to identify, separate, and characterize the major degradation product (DPs) of flucloxacillin, generated under various stress conditions. To achieve this objective, flucloxacillin was subjected to hydrolytic, oxidative, photolytic, and thermal stress as per International Conference on Harmonization (ICH) guidelines Q1A(R2). The drug was found to degrade in acidic, alkaline, neutral, and oxidative stress conditions and showed stable behavior in photolytic and thermal stress conditions. In total, seven degradation products were formed, which were separated on a C-18 column employing a gradient high-performance liquid chromatographic (HPLC) method. A complete mass fragmentation pathway of the drug was established with the help of multi-stage (MSn) and mass spectrometry/time of flight (MS/TOF) accurate mass studies. Then the stress samples were subjected to LC-MS/TOF studies, which provided the fragmentation pattern along with the accurate masses for a major degradation product. The entire mass spectral studies helped to identify the degradation product so as to propose its best possible structure. Finally the total information was used to establish the degradation pathway of the drug.
Authors:Ahmad Jamshidi, Hamid Mobedi and Farzaneh Ahmad-Khanbeigi
A new stability-indicating HPTLC assay has been established for leuprolide acetate. Silica gel 60F
was used as stationary phase. Samples and reference standards were applied to the same precleaned and activated HPTLC plates and chromatography was performed in an automated multiple development chamber (AMD2) with five-step isocratic incremental multiple development with 1 min drying time between each step and layer conditioning with the mobile phase before each development. The mobile phase, ethyl acetate-methanol-25% aqueous ammonia, 60 + 30 + 10, resulted in dense, compact zones for the analyte and related substances. Leuprolide acetate was subjected to acidic, basic, and oxidative degradation. The peaks of the degradation products were well resolved from the main peak with significantly different migration distances. Densitometric evaluation was performed at
= 280 nm. The calibration function of the analyte was linear in the range 107–422 ng and the correlation coefficient was 0.9914. The limits of detection and quantitation were 25 and 107 ng, respectively. The recovery and relative standard deviation obtained from between-days analysis were 97.06–102.0% and 1.34–2.90%, respectively. The method was shown to be suitable for use as a stability-indicating analytical procedure for assay of leuprolide acetate. The method enables high throughput and is easy to perform.
Authors:Aziz Ahmed, Sayeed Ahmad, Mahfooz Ur-Rahman, Tamboli E. Tajuddin, Ranbir Verma, Mohd Afzal and Prahlad Singh Mehra
Bacoside A, a triterpenoid saponin, is a major constituent isolated from Bacopa monnieri (L.) Wettst. (Scrophulariaceae), used as a memory enhancer. Bacoside A and B are active ingredients in Bacopa herb and have antioxidant and hepatoprotective activities
A new rapid, simple, and economical high-performance thin-layer chromatographic (HPTLC) method was developed and validated for densitometric quantitative analysis of bacoside A in powdered leaves from different geographical regions of India.
Materials and methods
An amount of 10 mg mL−1 methanol extract of powdered leaves from different geographic regions was used for sample application on precoated silica gel 60 F254 aluminum sheets. Standard bacoside A (1 mg mL−1) was used for calibration curve. HPTLC separation was performed on percolated silica gel aluminum plate 60 F254 (20 cm × 10 cm with 0.2 mm thickness) as a stationary phase using ethyl acetate–methanol–water (4:1:1) as the mobile phase. Quantification was achieved by densitometric analysis at 598 nm over the concentration range of 500–4000 ng band−1.
Compact and well-resolved bands for bacoside A from powdered leaves of different geographic regions were found at retardation factor (Rf) 0.53 ± 0.02. The linear regression analysis data for calibration curve showed good linear relationship with regression coefficient r2 = 0.9996 and r2 = 0.99810 with respect to peak area and peak height. The method was validated for precision, recovery, and robustness as per the International Conference on Harmonization (ICH) guidelines. Variation in quantitative analysis of bacoside A in powdered leaves sample from different geographic regions was found by HPTLC method.
Discussion and conclusion
The highest and lowest content of bacoside A in powdered leaves sample from Jammu and Kerala regions, respectively. The variety of B. monnieri in Jammu is superior to other regions of India. The proposed developed HPTLC method can be applied for the quantitative determination of bacoside A in powdered leaves of plant and its formulation.
Authors:P. R. Desai, P. J. Mehta, S. K. Ojha and A. B. Chokshi
), and percentage of mobile phase B of the initial gradient elution condition (37% and 47%).
The capacity of the method to detect the responses of the impurities without interferences was
Authors:M. Y. Salem, N. N. El Din Salama, L. M. Abd El-Halim and L. El-Sayed Abdel Fattah
Two sensitive and selective chromatographic methods have been developed and validated for analysis of idrocilamide in the presence of its degradation products. Forced degradation studies were performed using HCl, NaOH, and 3% H2O2. The first method is based on thin-layer chromatographic separation of the intact drug from its degradation products, followed by densitometric measurement. The second method is based on isocratic reversed phase high-performance liquid chromatographic separation of the drug from its degradation products on a C18 column. The HPLC method was used to investigate the kinetics of alkaline degradation of the drug at different temperatures.
Authors:K. Pramod, U. K. Ilyas, M. Singh, Y. T. Kamal, S. Ahmad, S. H. Ansari and J. Ali
High-performance thin-layer chromatography (HPTLC) method for the quantification of eugenol from nanostructured drug delivery systems was successfully developed and validated. The mobile phase consisted of n-hexane:acetone (7:3, v/v), and the densitometric scanning was performed in the absorbance mode at 280 nm. The method was valid with respect to linearity and range, accuracy, precision, specificity, detection limit (DL), and quantitation limit (QL). The linearity of the method was established by a correlation coefficient value of 0.9930 ± 0.0013. The precision was tested by checking intra-day (repeatability) and inter-day (intermediate precision) variations. The method was established to be precise by low relative standard deviation (RSD) values for different concentration of eugenol. The results of the recovery studies of eugenol from preanalyzed samples demonstrated the accuracy of the method. The specificity of the developed method for the analysis of eugenol in the nanoemulsion gel and nanoparticles samples was confirmed by comparing the spectra obtained in standard and sample analysis. The DL and QL were determined to be 31.41 and 95.17 ng band−1, respectively, for the HPTLC method. The forced degradation studies revealed on eugenol established the effectiveness of the developed and validated method. The developed and validated HPTLC method was found to be a stability-indicating one, as indicated by the results of forced degradation studies, for its use during the accelerated stability studies of the nanoemulsion gels and nanoparticles of eugenol.
Authors:J. Cielecka-Piontek, A. Krause, P. Zalewski, A. Lunzer and A. Jelińska
A stability-indicating LC assay method was developed and validated for the quantitative determination of doripenem and biapenem in pharmaceutical dosage forms in the presence of degradation products formed during forced degradation studies. An isocratic RP-HPLC method was developed with a C-18 (250 mm × 4.6 mm, 5 μm) column and 12 mM ammonium acetate-acetonitrile (96:4 υ/υ) as mobile phase. The flow rate of the mobile phase was 1.0 mL min−1 for doripenem and biapenem. The determination was carried out at the wavelength of 295 nm. The carbapenems were subjected to stress conditions of degradation in aqueous solutions including hydrolysis, oxidation, photolysis, and thermal degradation. The developed method was validated with respect to linearity, accuracy, precision, selectivity, and robustness.