Method Development

A simple, precise, and accurate method was developed for the simultaneous estimation of Nivolumab (NVM) and Cabozantinib (CBZ) in tablet dosage form.  The chromatogram was analyzed through a Phenomenex C18 150 mm (4.6 x 150 mm, 5 m) for chromatogram processing. A mobile phase containing formic acid: methanol (50:50) was pumped through the column at a spurge flow of 1.0 mL/min.  The column temperature was upheld at 30°C.  The quantification was done at 260.0 nm.  The elution time of NVM and CBZ was found to be 2.243 min and 2.953 min, respectively. The validation for the developed method was performed and all the parameters were found within the specified limits. The standard curve results represent a correlation coefficient of more than 0.999.  The %RSD of NVM and CBZ were found to be 0.9 and 0.7, respectively.  % Recovery was achieved as 99.88% and 99.66% for NVB and CBZ, respectively. The NVM and CBZ regression equations yielded LOD and LOQ values of 0.63, 1.91, and 0.08, 0.24 respectively. The equation of Nivolumab y is 39306x + 12173 while the Cabozantinib y is 34894x + 1139.7. With all the parameters under the criteria, the developed method for the simultaneous estimation of Nivolumab and Cabozantinib can be successfully applied for regular quality control approaches.

A new, simple, accurate, precise and robust isocratic RP-HPLC method has been developed and subsequently validated for the determination of Regorafenib in pure form and pharmaceutical dosage forms as per ICH guidelines. The separation achieved on a Symmetry C18 Column, 250 mm x 4.6 mm i.d. and 5µm particle size column as a stationary phase and Methanol: Phosphate buffer (pH adjusted to 4.80 with phosphoric acid) in the ratio of 70:30v/v used as mobile phase at a flow rate of 1.0 ml/min. The UV detection was performed at 268nm. The retention time for Regorafenib was found to be 3.544minutes. The detector response was linear in the concentration range of 0-16µg/ml. The respective linear regression equation being Y= 58945.x + 9634 with R2 = 0.999. The percentage of Regorafenib in pharmaceutical dosage form was found to be within the limits. The limit of detection and the limit of quantification were found to be 0.90µg/ml and 2.90µg/ml respectively. The results of the study showed that, the proposed RP-HPLC method was simple, rapid, precise, accurate and stability indicating, which can be used for the routine determination of Regorafenib in pure form and pharmaceutical dosage forms.

Albendazole (ALB), chemically known as methyl [5-(propylthio)-1H-benzimidazol-2-yl] carbamate is widely used as an anthelmintic having a wide spectrum of activity. Numerous numbers of analytical methods are there for the simultaneous estimation of bulk and in formulation, such as spectrophotometry and liquid chromatography. As the UV spectrophotometric method is rapid, simple, accurate and economical, the method has been developed for the assay of the albendazole in pharmaceutical formulation. The wavelengths selected for the method were at 291 nm. The results of analysis have been validated by recovery studies as per ICH guidelines. The developed method was rapid, simple, accurate and economical and it can be used for routine quality control analysis. It showed absorption maxima at 291 nm in analytical grade DMF. The drug obeyed the Beer’s law and showed good correlation of concentration with absorption which reflect in linearity.

A Novel stability-indicating method was developed and validated by Reverse phase Hplc method   for the estimation of Thiotepa in Lyophilized form. The simple, Accurate Assay method was developed by PDA Detector at 215nm and column(YMC,150mmx4.6mm, 3.5 μm,12nm).The mobile phase A consisted of (3.5g of potassium Dihydrogen phosphate/1liter: 4.2g of Disodium hydrogen Phosphate/2liters)Buffer : Acetonitrile (85:15v/v) and The mobile phase B consisted of (3.5g of potassium Dihydrogen phosphate/1liter: 4.2g of Disodium hydrogen Phosphate/2liters)Buffer : Acetonitrile (50:50v/v) gradient flow rate at 1.0 mL/min for 30minutes. Samples was stored at 5°c temperature in sample cooler and Column oven temperature was maintained  in the method at 30°c  Respectively. The retention time of Thiotepa was 11.313 minutes. The proposed method was developed and validated with respect to specificity, accuracy, precision, linearity, Analyte Stability. Specificity of the Assay method shows no interference from Diluent and degrading products formed by alkaline, acidic, oxidative, Water Hydrolysis conditions. At Each level, %Recovery of Thiotepa in formulations was obtained to be in a range of 98-102%. The linearity of the assay was established in the range of 159.915-479.744µg/mL with correlation coefficient (R2) > 0.9999. This method was shows simple, precise, more accurate, stability indicating and reliable determination of Thiotepa for drug stability assay in pharmaceutical studies.

A simple, accurate and sensitive RP-HPLC method was developed and validated for the determination of candesartan cilexetil and hydrochlorothiazide in tablet dosage form. The separation of the two drugs was achieved on a Reprospher 100 –C l 8 column (250 x 4.6 mm, 5 µm particle size) with UV detection at 260 nm. The mobile phase consists of two solution, solution (1) orthophosphoric acid (pH 2.2) and the solution (2) which is acetonitrile and purified water in the ratio 55: 45 v/v, respectively. The method was validated in terms of linearity, accuracy, precision, specificity, limit of detection, limit of quantitation and robustness. Linearity was observed in the concentration range 10-70µg/ml for hydrochlorothiazide and 12.8 -89.6µg/ml for candesartan cilexetil. The limit of quantitation was found to be 8.58 and 4.6 µg/ml for hydrochlorothiazide and candesartan cilexetil, respectively whereas the limit of detection, was found to be 2.8 and 1.5 µg /ml for hydrochlorothiazide and candesartan cilexetil, respectively. The % recovery range of candesartan cilexetil was 97.84-101.62% and 100.9-101.53% for hydrochlorothiazide. Variation in HPLC conditions (flow rate, column temperature, mobile phase composition, and wavelength) were used to evaluate the robustness of the method. The method proved to be robust and still produces good results.

An accurate, precise and reproducible high performance liquid chromatographic method was developed for the simultaneous estimation of lamivudine, zidovudine and nevirapine in pharmaceutical dosage forms. Phenomenex C18 column (250 x 4.6 mm; 5µ) was employed for the separation of drugs. A mixture of 0.02 M trichloroacetic acid (6.8 pH) and methanol in the ratio of 40:60 v/v was used as the mobile phase and pumped at a flow rate of 1ml/min. The detection wavelength was set at 265 nm. The linearity of quantification was observed in the range of 7.5-112.5, 10-150 and 15-225 μg/ml for lamivudine, zidovudine and nevirapine respectively. The proposed method was validated according to ICH guidelines. The method was found to be suitable for simultaneous and accurate determination of these drugs in tablet dosage forms without any interference from the excipients.