UV spectrophotometry

The aim of present work was to develop an accurate, precise, reproducible and economical UV spectrophotometric method for estimation of 1H, 1’-H-2, 2’-Bibenzimidazole Impurity In Telmisartan Bulk and Formulation. This method was based on area under curve of UV spectrum between 235 to 254 nm and validated as per ICH guideline Q2 (R1). The method has followed linearity in the range of 5-30μg/ml. The value of correlation coefficient was 0.998. Satisfactory values of Percent relative standard deviation for the intra-day and inter-day precision indicated that method is precise. Results of the recovery studies (97.63% to 98.66 %) showed accuracy of the method. LOD and LOQ were calculated as 0.3221μg/ml and 0.9761 μg/ml, respectively. The developed method can be used for routine estimation of 1H, 1’-H-2, 2’-Bibenzimidazole Impurity In Telmisartan Bulk and Formulation.

A simple, accurate and precise UV spectrophotometric method has been developed for the quantitative estimation of Efavirenz in bulk and tablet dosage form. The λmax was found to be 239 nm. Beer’s law was obeyed in the concentration range of 10-20μg/ml. The regression equation was Y=0.052x-0.113 with value of R2 as 0.996. The method showed good linearity, accuracy and reproducibility. Accuracy as expressed mean percent recovery ± standard deviation was found to be 95.29% ± 0.0429. Percent relative standard deviation values for the intra-day and inter-day precision studies were found to be 0.23 and 0.31, respectively. The limit of detection and limit of quantitation values were found to be 1.39 and 4.22, respectively. Assay of Efavirenz in tablet formulation was performed and percent purity of tablet was found to be 98.65% ± 0.0078.

Meloxicam has been analyzed in a number of ways but the methods proved to be slow and tedious due to the involvement of buffers, maintaining of pH and lengthy process of HPLC or potentiometric titration. Our aim was development and validation of a new, fast, simple and inexpensive method for the analysis of Meloxicam by UV visible spectrophotometry. A new solvent system consisting of Acetonitrile and Methanol (70:30) was formulated by trial and error method. Different concentrations of meloxicam were made in this solvent system and were analyzed by UV visible spectroscopy. The absorbance was studied over the range of 240 to 400nm. The obtained results were used to study and calculate various validation parameters of this technique.  The calibration curve was found to be linear over the range of 0.1 to 0.6ug/ml with linear coefficient of 0.999. The precision was calculated to be equivalent to 0.251%. The LOD and LOQ of this method were found to be around 0.006ug/ml and 0.02ug/ml respectively. The system showed accuracy over the range of 90-100%. This method proved to be a good alternative to existing reported methods as it showed sensitivity, accuracy as well as reproducibility with low cost and time.

The aim of present work was to develop an accurate, precise, reproducible and economical UV spectrophotometric method for estimation of Loratadine. This method was based on area under curve of UV spectrum between 241 to 251 nm and validated as per ICH guideline Q2 (R1). The method has followed linearity in the range of 5-30µg/ml. The value of correlation coefficient was 0.999. Satisfactory values of Percent relative standard deviation for the intra-day and inter-day precision indicated that method is precise. Results of the recovery studies (99.66 % to 99.95 %) showed accuracy of the method. LOD and LOQ were calculated as 0.581 µg/ml and 1.935 µg/ml, respectively. The developed method can be used for routine estimation of Loratadine in bulk and tablet dosage forms.

Quantitative estimation of temozolamide and its pharmaceutical dosage form by UV spectroscopy, RP-HPLC, HPTLC methods was developed. In the UV method (geometric method), temozolamide was quantified at 309nm, 325nm, 340nm in serum and water. The corrected absorbance was calculated. The Recovery studies was found to be 95.5-96.9%. In RP-HPLC method, the drug was resolved using a mobile phase methanol: buffer (5.0ml glacial acetic acid in 1000ml water) (70:30%v/v) on C18 column in isocratic mode. The retention time of temozolamide was found to be 7.30 min. Recovery studies was found to be 99.55-100.98%.  In HPTLC method, the chromatograms were developed by using a mobile phase Chloroform: glacial acetic acid: methanol (2:3:5% v/v) on precoated plate of silica gel 60F254 and quantified by densiometric absorbance mode at 254nm. The Rf value of Temozolamide was 0.47. Recovery studies of 98.99-100.6%, percentage relative standard deviation (%RSD less than 2%) and correlation coefficient (linearity range) that developed methods were accurate and precise. These methods can be employed for the routine analysis of capsules containing temozolamide. Key words: Temozolamide, RP-HPLC, HPTLC, UV spectrophotometry, validation.

A reversed phase high-performance liquid chromatographic method was developed and validated for the quantitative determination of two antiviral drugs viz. lopinavir and ritonavir. Chromatography was carried out by gradient  technique on a reversed-phase C18 Column, Phenomenex (250 x 4.6 mm, 5 µ) with mobile phase mixture of Buffer: Acetonitrile (45:55 v/v) was used as a mobile phase and the pH was adjusted into 4.5 by using with O-phosphoric acid, at a flow rate of 1.2 ml/min. The UV range was detected at 240nm for lopinavir and ritonavir respectively. The different analytical performance parameters such as linearity, precision, accuracy, and specificity, limit of detection (LOD) and limit of quantification (LOQ) were determined according to International Conference on Harmonization ICH Q2B guidelines. The linearity of the calibration curves for each analyte in the desired concentration range is good (r2 >0.9). The recovery of the method was between 102.1% and 100.1% for lopinavir and ritonavir respectively. Hence the proposed method is highly sensitive, precise and accurate and it successfully applied for the reliable quantification of API content in the commercial formulations of lopinavir and ritonavir. Key words: Lopinavir, Ritonavir, UV spectrophotometry, RP-HPLC.

  Quantitative estimation of Trapidil and its pharmaceutical dosage form by HPLC, HPTLC and UV spectroscopy methods was developed. In the RP-HPLC method, the drug was resolved using a mobile phase phosphate buffer: acetonitrile (30:70%v/v) with pH adjusted to 3.5 using phosphoric acid on C18 column in isocratic mode. The retention time of trapidil was found to be 3.195 min.  In HPTLC method, the chromatograms were developed by using a mobile phase Methylene chloride: Methanol:  ammonia (8.5:1:0.5 v/v) on precoated plate of silica gel 60F254 and quantified by densiometric absorbance mode at 312nm. The Rf value of Trapidil was 0.28. In the UV method, trapidil was quantified at 221nm in acetronitrile. Recovery studies of 98.8-101.14%, percentage relative standard deviation (%RSD less than 2%) and correlation coefficient (linearity range) that developed methods were accurate and precise. These methods can be employed for the routine analysis of tablets containing trapidil.   Key words: Trapidil, RP-PHLC, HPTLC, UV spectrophotometry, validation