title: Development and validation of a simple, sensitive, selective and stability-indicating RP-UPLC method for the quantitative determination of ritonavir and its related compounds.
abstract: A simple, sensitive, selective and reproducible stability-indicating ultra-performance liquid chromatographic method was developed for the quantitative determination of degradation products and process-related impurities of Ritonavir in a pharmaceutical dosage form. Chromatographic separation was achieved on a polar embedded Waters Acquity BEH Shield RP18 (100 × 2.1 mm, 1.7 μm) column thermostated at 50°C under gradient elution by using a binary mixture of potassium dihydrogen phosphate (0.01 M, pH 3.5) and acetonitrile at a flow rate of 0.5 mL/min. Chromatogram was monitored at 240 nm using a photodiode array detector. The drug and its related impurities are eluted within 20 min. To prove the stability-indicating power of the method, the drug was subjected to hydrolytic (acid, alkaline and water), oxidative, photolytic and thermal stress conditions. The unknown degradants were identified by the LC-MS-MS method, which revealed protonated molecular ion peaks [M + H](+) at m/z 551.40 for hydrolytic degradants, and m/z 737.60 and m/z 753.40 for photolytic degradants. A plausible mechanism for the formation of degradation and process impurities was proposed. The performance of the method was validated according to the International Conference on Harmonization guidelines.
authors.affiliation: Analytical Research and Process Development, Integrated Product Development Operations, Dr Reddy's Laboratories Ltd, Bachupally, Qutubullapur, Ranga Reddy District 500 072, Andhra Pradesh, India Centre for Chemical Sciences and Technology, IST, J. N. T. University, Kukatpally, Hyderabad 500085, Andhra Pradesh, India srinivasaraokoppala@gmail.com srinivas_organic@rediffmail.com.
authors.forename: Srinivasarao
authors.initials: S
authors.lastname: Koppala
authors.affiliation: Analytical Research and Process Development, Integrated Product Development Operations, Dr Reddy's Laboratories Ltd, Bachupally, Qutubullapur, Ranga Reddy District 500 072, Andhra Pradesh, India.
authors.forename: Bibhuranjan
authors.initials: B
authors.lastname: Panigrahi
authors.affiliation: Analytical Research and Process Development, Integrated Product Development Operations, Dr Reddy's Laboratories Ltd, Bachupally, Qutubullapur, Ranga Reddy District 500 072, Andhra Pradesh, India.
authors.forename: S V N
authors.initials: SV
authors.lastname: Raju
authors.affiliation: Analytical Research and Process Development, Integrated Product Development Operations, Dr Reddy's Laboratories Ltd, Bachupally, Qutubullapur, Ranga Reddy District 500 072, Andhra Pradesh, India.
authors.forename: K
authors.initials: K
authors.lastname: Padmaja Reddy
authors.affiliation: Analytical Research and Process Development, Integrated Product Development Operations, Dr Reddy's Laboratories Ltd, Bachupally, Qutubullapur, Ranga Reddy District 500 072, Andhra Pradesh, India.
authors.forename: V
authors.initials: V
authors.lastname: Ranga Reddy
authors.affiliation: Centre for Chemical Sciences and Technology, IST, J. N. T. University, Kukatpally, Hyderabad 500085, Andhra Pradesh, India.
authors.forename: Jaya Shree
authors.initials: JS
authors.lastname: Anireddy