RP-LC gradient elution method for simultaneous determination of thiocolchicoside, aceclofenac and related impurities in tablet formulation.

OBJECTIVE: The aim of the present study is to develop a simple and precise HPLC method for simultaneous determination of thiocolchicoside, aceclofenac and related impurities in a tablet formulation and validate as per ICH guidelines. The aim of study extends to perform forced degradation study to trace the degradation pathways of potential degradant impurities. MATERIALS AND METHODS: The separation was achieved on a 4.6 mm × 100 mm, 3 µm C18 column at 40°C with the mobile phase containing 0.1 M ammonium acetate buffer and methanol in a gradient mode at a flow rate of 1.0 mL min(-1). The UV detection was carried out at 257 nm. RESULTS: Acelofenac, thiocolchicoside and their related compounds were well separated from each other with good resolution and symmetry factor without interference of excipients. The method for assay was linear in the range of 10-200 µg mL(-1) for aceclofenac and 0.4 to 8 µg mL(-1) for thiocolchicoside. CONCLUSION: The method was validated according to ICH guidelines and the acceptance criteria for accuracy, precision, linearity, specificity, robustness, ruggedness and system suitability were met in all cases. The method was highly specific, as two related compounds of thiocolchicoside and nine related compounds of aceclofenac were well separated from each other. Stress study ensured the specificity of the method as the unknown degradation products formed during stress studies did not interfere with the determination of thiocolchicoside and aceclofenac, thus proving the stability indicating capacity of the method.

Comparison of seven Oxethazaine containing antacids available in the Indian market.

OBJECTIVE: This in-vitro study was designed to measure the quantity of acid neutralized by a suspension of a commercial antacid available in Indian markets at a labeled dose and to test the concept of the relative effectiveness of 7 different commercial antacids containing Oxethazaine. METHODS: A simple back titration methodology was used to determine the acid neutralization capacity (ANC) of antacids. RESULTS: It was observed that different antacids vary widely in their in vitro ANC. There was also a batch to batch variation noted for each brand of antacid. The analysis indicated that there was a significant difference of ANC in favor of AD versus other antacids studied. CONCLUSION: Comparison of relative effectiveness indicates that AD has highest ANC in vitro amongst other antacids. However, the present study being in vitro, the effects of antacid may vary in vivo, as individual variations also contribute to the ultimate effectiveness of an antacid.

Simultaneous determination of diclofenac potassium and drotaverine hydrochloride in human plasma using reversed-phase high-performance liquid chromatography.

A simple high-performance liquid chromatographic method with ultraviolet detection is proposed for the estimation of diclofenac potassium and drotaverine hydrochloride in human plasma. Liquid-liquid extraction was carried out with a mixture of dichloromethane-isopropyl alcohol (80:20, v/v). Chromatographic separation of the analytes and internal standard was achieved on an analytical 250 × 4.6 mm i.d. reversed-phase Thermo BDS Hypersil C8 (5 µm particle size) column using a mobile phase of acetonitrile-0.02M ammonium acetate buffer (53:47, v/v) at pH 3.5. The run time was less than 15 min. Column eluate was monitored at 230 nm. The linearity over the concentration ranges of 25-1500 ng/mL and 32-960 ng/mL was obtained for diclofenac potassium and drotaverine hydrochloride, respectively. The limit of quantification was 25 and 32 ng/mL for diclofenac potassium and drotaverine hydrochloride, respectively. Recoveries of diclofenac potassium and drotaverine hydrochloride from plasma were 97.45% and 98.27%, respectively.

Identification of Forced Degradation Products of Itopride by LC-PDA and LC-MS.

Degradation products of itopride formed under different forced conditions have been identified using LC-PDA and LC-MS techniques. Itopride was subjected to forced degradation under the conditions of hydrolysis, photolysis, oxidation, dry and wet heat, in accordance with the International Conference on Harmonization. The stress solutions were chromatographed on reversed phase C18 (250×4.6 mm, 5 µm) column with a mobile phase methanol:water (55:45, v/v) at a detection wavelength of 215 nm. Itopride degraded in acid, alkali and oxidative stress conditions. The stability indicating method was developed and validated. The degradation pathway of the drug to products II-VIII is proposed.

RP-HPLC method for simultaneous estimation of bisoprolol fumarate and hydrochlorothiazide in tablet formulation.

A simple, precise and stability-indicating HPLC method was developed and validated for the simultaneous determination of bisoprolol fumarate and hydrochlorothiazide in pharmaceutical dosage form. The method involves the use of easily available inexpensive laboratory reagents. The separation was achieved on an Inertsil ODS 3V (25cmx4.6mm) 5microm column with isocratic flow. The mobile phase at a flow rate of 1.0mLmin(-1), consisted of 0.1M potassium dihydrogen phosphate buffer and acetonitrile (70:30, v/v). The UV detection was carried out at 228nm. A linear response was observed over the concentration range 2.5-50microgmL(-1) of bisoprolol fumarate and the concentration range 6.25-125microgmL(-1) of hydrochlorothiazide. Limit of detection and limit of quantitation for bisoprolol fumarate were 0.01 and 0.03microgmL(-1), respectively and for hydrochlorothiazide were 0.01 and 0.05microgmL(-1), respectively. The method was successfully validated in accordance to ICH guidelines acceptance criteria for specificity, linearity, accuracy, precision, robustness, ruggedness and system suitability. Individual drugs (bisoprolol fumarate and hydrochlorothiazide), their combinations and the tablets were exposed to thermal, photolytic, hydrolytic and oxidative stress conditions. The resultant stressed samples were analyzed by the proposed method. The method gave high resolution among the degradation products and the analytes. The peak purity of analyte peaks in the stressed samples was confirmed by photodiode array detector. The method was used for accelerated stability study on marketed and in-house formulations. The analysis concluded that the method was selective for simultaneous estimation of bisoprolol fumarate and hydrochlorothiazide and was stability-indicating.