degradation products

A simple, specific, accurate and stability-indicating reversed phase High Performance Liquid Chromatographic method was developed for the simultaneous determination of Clindamycin Phosphate and Benzoyl Peroxide, using a C18 column and a mobile phase composed of 20 mM Ammonium acetate buffer pH 4.0: Methanol (45: 55 %v/v) as mobile phase at flow rate of 1.2 ml/min with detection wavelength of 210nm. Retention times in RP-HPLC method were found to be 4.49 min, 8.78 min for Clindamycin Phosphate and Benzoyl Peroxide, respectively. Linearity of Clindamycin Phosphate and Benzoyl Peroxide were found in the range of 10.0-30.0 µg/ml and 25.0-75.1 µg/ml. The % recovery of Clindamycin Phosphate was found to be 98.45- 101.0 and 99.8- 99.38 for Benzoyl Peroxide. Both the drugs were subjected to acid, alkali, oxidation, thermal and sunlight degradation. The degradation products of Clindamycin Phosphate and Benzoyl Peroxide were well resolved from the pure drugs with significant differences in the retention time values. This method can be successfully employed for simultaneous quantitative analysis of Clindamycin Phosphate and Benzoyl Peroxide in gel formulation. The literature survey reveals that currently there is no stability indicating method has been reported for combination of Clindamycin Phosphate and Benzoyl Peroxide till date, Which can be applicable for routine analysis of combined formulation of drugs in quality control laboratories.

A simple, specific, sensitive, precise and stability-indicating reversed phase high performance liquid chromatographic method was developed and validated for the simultaneous determination of thiocolchicoside and aceclofenac, using a RP-18 column and a mobile phase composed of 0.1% trifluoroacetic acid: acetonitrile (45:55). The retention time of thiocolchicoside and aceclofenac were found to be 2.35 and 13.2 min, respectively. Linearity was established for both thiocolchicoside and aceclofenac in the range of 0.08-0.8 and 1-10 µg/ml. Both the drugs were subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, and photolytic degradation. The degradation studies indicated that both thiocolchicoside and aceclofenac were susceptible to acid, alkaline and neutral hydrolysis. The degradation products of thiocolchicoside and aceclofenac were well resolved from the pure drugs with significant differences in the retention time values. This method can be successfully employed for simultaneous quantitative analysis of thiocolchicoside and aceclofenac in bulk drugs and formulations.

To assure the quality of drugs, impurities must be monitored carefully. It is important to understand what constitutes an impurity and to identify potential sources of such impurities. Selective analytical methods need to be developed to monitor them. It is generally desirable to profile impurities to provide a yardstick for comparative purposes. New impurities may be observed as changes are made in the synthesis, formulation, or production procedures, albeit for improving them. At times it is necessary to isolate and characterize an impurity when hyphenated methods do not yield the structure or when confirmation is necessary with an authentic material. Availability of an authentic material can also allow toxicological studies and provide a standard for routine monitoring of the drug product.

A simple, specific, accurate and stability-indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of thiocolchicoside  and lornoxicam, using a RP-18 column and a mobile phase composed of 10mM ammonium acetate : methanol(50:50), pH7 adjusted with 1%triethyl amine. The retention time of thiocolchicoside and lornoxicam were found to be 4.6 and 10.2 min, respectively. Linearity was established for both thiocolchicoside and lornoxicam in the range of 1-10 µg/ml. The percentage recoveries of thiocolchicoside and lornoxicam were found to be 100.45±0.4489 and 100.70±0.5111, respectively. Both the drugs were subjected to acid, alkali and neutral hydrolysis, oxidation, dry heat, and photolytic degradation. The degradation studies indicated thiocolchicoside to be susceptible to acid, alkaline and neutral hydrolysis while lornoxicam showed degradation under acid and alkali. The degradation products of thiocolchicoside and lornoxicam were well resolved from the pure drugs with significant differences in the retention time values. This method can be successfully employed for simultaneous quantitative analysis of thiocolchicoside and lornoxicam in bulk drugs and formulations.