Amlodipine

The objective of the present research work was to simultaneously separate the anti-hypertensive agents, Amlodipine and Valsartan and develop a validated analytical method for simultaneous quantitative determination of amlodipine and valsartan in tablet dosage form. A simple, rapid, precise and selective chromatographic method was developed and validated for separation and determination amlodipine and valsartan in tablet preparations. The anti-hypertensive agents were analyzed by Symmetry C18, (150 × 3.4 mm, 5 µ), Shimadzu LC-2010CHT Prominence Liquid Chromatograph and a mobile phase constituted of 10 mM Buffer (pH 3.0): methanol (50:50, v/v). The flow rate was 1.0 mL/min and the analysis were performed using UV- Vis detector at 237nm. The anti-hypertensive agents, Amlodipine and Valsartan were separated within 10 min. Amlodipine and Valsartan showed retention time of 5.06 and 8.28 min respectively. The drugs were found to obey Beer’s law in the concentration range of 100 ppm of amlodipine and 128 ppm of valsartan. The developed assay method is selective, precise and accurate. The method has been successfully applied for determination of Amlodipine and Valsartan in pharmaceutical combination tablet dosage form. This developed method is sensitive, fast and simple with excellent peak symmetry and high resolution.

Drug Interactions have become very common now-a-days. In drug interactions there are mainly three types in that the most important interactions are drug-drug interactions. By keeping in mind about these interactions we have done research by taking Diabetes as the main disease and if same person is suffering any other disease like we have chosen Hypertension. Our main aim is to find out the Interactions between Glyburide and Amlodipine and another scenario is little different with another class of drug that is Enalapril and with Sulphonyl urea derivative drug that is Glyburide. We found that the Glyburide have shown the 49.9% of inhibition. The Amlodipine and Enalapril groups showed 28.9% and 33.7% inhibition rates against the Glyburide group. The combined groups Glyburide with Amlodipine and Glyburide with Enalapril have shown 39% and 43.3% inhibition rates. More results can be obtained if we have done Pharmacokinetic study.

Two simple, specific, precise and accurate spectrophotometric methods have been developed for the simultaneous estimation of Telmisartan (TEL) and Amlodipine besylate (AML) involving: second derivative Spectrophotometric method (I) and first derivative Ratio -Spectrophotometric Method (II). Method (I) is based on measurement of amplitude of second derivative spectrum absorbance at two wavelengths; 329 nm and 368 nm for Telmisartan and Amlodipine besylate respectively. The latter (method II) depends on measurement of amplitude of the first derivative of the ratio spectrum at two wavelengths, 319 nm and 288 nm for Telmisartan by using 2 µg/mL of AML as a divisor and 393 nm for Amlodipine besylate by using 4 µg/mL of TEL as a divisor. Beer's law obeyed in concentration range of 1 - 35 µg/ mL and 2- 16 µg/ mL for Telmisartan and Amlodipine besylate respectively for both methods. The proposed methods are recommended for routine analysis since they are rapid, simple and specific. The described UV methods were successfully employed for the analysis of each drug in their combined dosage form. For method (I), the mean% recoveries were found to be 100.49±0.15 for Amlodipine besylate and 98.99±1.83 for Telmisartan. For method (II), the mean% recoveries were found to be 99.55±0.92 and 100.48±1.69 for Telmisartan at 319 nm and 288 nm respectively and 99.92±1.69 for Amlodipine besylate at 393 nm. The validation of methods was carried out utilizing ICH guidelines.

A simple, rapid, and precise RP-HPLC method for simultaneous analysis of Amlodipine besylate and Glimepiride in bulk and its pharmaceutical formulations has been developed and validated. Amlodipine besylate was separated from Glimepiride by using Grace Smart Altima C8 column (25 cm × 4.6 mm, 5-μm) with a mobile phase consisting of acetonitrile: 20mM phosphate buffer (55:45 (v/v), pH 3.5) a flow rate of 1 mL/min and detection wavelength at 230 nm.  Amlodipine besylate and Glimepiride were eluted with retention times of 5.47 min and 14.17 min respectively. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with ICH (Q2B) guidelines. The results of all the validation parameters were found to be within the acceptable limits. The calibration plots were linear over the concentration ranges from 70-3000ng/mL for Amlodipine besylate and 100-3000ng/mL for glimepiride. The limit of detection and limit of quantification were found to be 19.4ng/mL and 58.8ng/mL for amlodipine besylate, 25.6ng/mL and 76.2ng/mL for glimepiride respectively for both the drugs. From the results it is suggested that the method is simple, reproducible, accurate and precise. The method was successfully applied for the determination of content and the dissolution profile of the combined bilayer tablet dosage form.

The main aim of research work was to design novel bilayer fast dissolving films as a drug delivery system for treatment of severe hypertension and acute cases like angina pectoris. In present work two incompatible drugs Amlodipine and Benazapril was combined in single dosage form using impermeable membrane. The thin films of both drugs were prepared by using different concentration of polymers, plasticizers and super disintegrants. The films were casted in to bilayer films using impermeable membrane. These prepared Bilayer films were characterized on basis of thickness, folding endurance, tensile strength and dissolution time. On basis of study it was found that the optimized film dissolves within 60 sec. and both drugs do not show interaction during preparation and stability period. The proposed novel films will deliver the two incompatible drugs and releases the drug quickly thus can be preferred in hypertension emergencies.