UV Spectrophotometry

A simple, precise, and accurate UV spectrophotometric method was developed and validated for the simultaneous estimation of Lornoxicam and Thiocolchicoside in bulk and pharmaceutical formulations. The method employs methanol as solvent, and absorbance was measured at the respective wavelengths where both drugs showed maximum absorbance with minimal interference. Calibration curves were linear within the concentration ranges of 4–20 µg/mL for Lornoxicam and 5–25 µg/mL for Thiocolchicoside, with correlation coefficients (R²) of 0.9992 and 0.9995, respectively. Validation was carried out according to ICH Q2(R1) guidelines, including parameters such as linearity, accuracy, precision, LOD, LOQ, robustness, and ruggedness. Recovery studies at 50%, 100%, and 150% levels showed recoveries between 98.7–100.1%, indicating high accuracy. The proposed method is suitable for routine quality control of combined dosage forms of Lornoxicam and Thiocolchicoside.

A new, simple and sensitive UV-spectrophotometric method was developed for the determination of Benfotiamine in bulk and tablet dosage form. This method, involves the measurement of absorbances of Benfotiamine at the wavelength of 244nm. 0.1M HCl was used as solvent. Linearity was observed in the concentration range of 3-18µg/ml with correlation coefficient 0.999. The accuracy of the method was confirmed by recovery studies of tablet dosage forms and was found to be 99.32%-100.42% for Benfotiamine. The method showed good reproducibility and recovery with %RSD lessthan 2.0. The LOD and LOQ of Benfotiamine was found to be 0.051μg/ml and 0.155μg/ml. Results of the analysis were validated for accuracy, precision, LOD, LOQ and were found to be satisfactory. Thus the developed method was found to be simple, sensitive, rapid, precise, accurate and cost effective quality control tool for the routine analysis of Benfotiamine in bulk and tablet dosage form.

Two novel methods having requisite precision, accuracy, specificity and robustness were developed and validated for quantitative determination of Apixaban in pharmaceutical dosage forms. The first method was based on isocratic reverse phase liquid chromatography using Sunfire C18, 150mm×4.6mm, 5µ and mobile phase consists of Buffer: acetonitrile (60:40) at a flow rate 1ml/min and detection was achieved photodiodide array detector set at 280 nm. The response was linear range of 5-50 µg/ml (R2 =0.9998). The second spectrophotometric method involves detection at 280 nm. The calibration curve range between 5-50 µg/ml (R2 =0.9999). Validation of method was carried out fulfilling ICH guidelines. Both the methods were applied without any interference from excipients, for determination of drug in coated tablets. It is suggested that the proposed HPLC and UV spectrophotometric methods could be used routine quality control and dosage form assay of Apixaban.

A simple, accurate, and precise UV spectrophotometric method has been developed and validated for simultaneous estimation of Cilnidipine and Valsartan in synthetic mixture. The estimation of drugs was done by Second Order Derivative spectrophotometric method using 219 nm and 227 nm wavelength. Methanol was used as a solvent. The Linearity was obtained in the concentration range of 2-10 µg/ml for Cilnidipine and 5-25 µg/ml for Valsartan with R2 0.9994 and 0.9980 respectively. Accuracy was determined by recovery studies and showed % recovery between 98 to 102 % for both the drugs. The LOD and LOQ values of Cilnidipine were found to be 0.33 and 1.01 and for Valsartan values were found to be 0.18 and 0.55. The developed method was validated as per the ICH Guidelines Q2 (R1).

Simple, accurate and precise and economical UV–spectroscopy method have been developed and validated for the estimation of Tadalafil and Fluoxetine HCl in a synthetic mixture. Tadalafil is used in treatment of Erectile Dysfunction and Fluoxetine HCl is used in depression. The Tadalafil and Fluoxetine HCl stock solutions are prepared in methanol solution. At zero crossing point (ZCP) of Tadalafil (230nm) Fluoxetine HCl showed a measurable derivative absorbance, whereas at zero crossing point (ZCP) of Fluoxetine HCl (235nm) Tadalafil showed a appreciable derivative absorbance value. The Tadalafil and Fluoxetine HCl are linear in concentration range of 5-25 μg/ml. Developed method was validated according to the ICH Q2 (R1) guidelines. The precision were found within limits (RSD< 2%). Accuracy were determined by recovery studies and showed % recovery between 97 to 100 % for both the drugs Tadalafil and Fluoxetine HCl. The LOD and LOQ values of Tadalafil at ZCP 230 nm were found to be 0.24 and 0.74 correspondingly and for Fluoxetine HCl at ZCP235nm were found to be 0.29 and 0.89 correspondingly.

To develop a fast and sensitive  UV spectrophotometric method for the quantitative estimation of Formaldehyde in Rivastigmine tartrate drug substances and validate as per ICH guidelines. The method was based upon the observation, that a characteristic colourresults upon addition of  solution of Pentane-2,4-dione , also known as acetylacetone . In acetic acid and ammonium acetate buffer condition, acetylacetone and formaldehyde react to form dimethyl pyridine. Dimethyl pyridine is slightly yellow and its absorption maximum in aqueous solution is λ 420 nmin Rivastigmine tartrate drug substance.The developed method resulted in Formaldehyde exhibiting linearity in the range 0.975 to 234 µg/g. The Intraday and interday precision is exemplified by relative standard deviation of 0.562 % and 0.757%. Percentage Mean recovery was found to be in the range of 98‐101%, during accuracy studies. The limit of detection (LOD) and limit of quantitiation (LOQ) were found to be 1.3 µg/g and 3.9 µg/g respectively.The present work was aimed to develop a visible spectrophotometric method, which is simple, sensitive, accurate and cost effective to evaluate the quality of the bulk drugs.

The present work was defined to develop area under curve method for antipsychotic drug by UV spectrophotometric analysis which was economical, precise and an accurate method for estimation of Quetiapine fumarate. This method was based on area under curve of UV spectrum between 287 to 297 nm and validated as per ICH guideline Q2 (R1). The linearity in the range was found to be 4-14 μg/ml. The result of correlation coefficient was 0.999. The results of percent relative standard deviation for the intra-day and inter-day precision indicated that method is precise. The values of the recovery studies (99.65 % to 101.04 %) showed good accuracy of the method. LOD and LOQ were calculated as 0.3806 and 1.153μg/ml, respectively. The developed method can be applied for routine estimation of Quetiapine fumarate in bulk and tablet dosage forms.

A simple, accurate, reliable and reproducible first order derivative method was developed for the simultaneous determination of Cefoperazone sodium (CEFO) and Tazobactam sodium (TAZO) in pharmaceutical formulation. The linearity was carried out by using the concentration range 5-50 µg/ml for CEFO (275.2 nm ZCP of TAZO) and 2-50 µg/ml for TAZO (225 nm ZCP of CEFO) respectively. The correlation coefficient of CEFO and TAZO was found to be 0.999 and 0.998 respectively. At zero crossing point (ZCP) of CEFO (225nm) TAZO showed a measurable derivative absorbance, whereas at zero crossing point (ZCP) of TAZO (275.20nm) CEFO showed a appreciable derivative absorbance value. Precision study showed that %RSD was within range of acceptable limits (< 2%). The % recovery for CEFO and TAZO was found to be within range of 98-101% and 98-102%respectively. The percentage assay was found to be 101.05% and 99.41% for CEFO and TAZO. The result of analysis has been validated as per ICH guideline. This method has applied successfully for determination of CEFO and TAZO in its pharmaceutical formulation. 

A simple, precise and economical UV Spectrophotometric method has been developed for the estimation of Tolterodine tartarate in bulk and pharmaceutical dosage form. The method is based on measurement of absorption at maximum wavelength of 283.0 nm. Linearity for detector response was observed in the concentration range of 10-50 μg/ml. The accuracy of the method was assessed by recovery studies and was found to be 99.80%. The LOD and LOQ were found to be 0.1865 and 0.5621 respectively. The developed method was validated with respect to linearity, accuracy (recovery), precision, specificity and robustness and ruggedness. The results were validated statistically as per ICH Q2 R1 guideline and were found to be satisfactory. The proposed method was successfully applied for the determination of Tolterodine tartarate in commercial pharmaceutical dosage form.