Sadanand Mallurwar - Academia.edu (original) (raw)
Papers by Sadanand Mallurwar
Biomedical and Pharmacology Journal
Purpose: The primary motive of this study was to examine advantages of allometry scaling strategi... more Purpose: The primary motive of this study was to examine advantages of allometry scaling strategies for correct prediction of pharmacokinetics of Baricitinib in human from preclinical species. Baricitinib is basically Janus kinase (JAK) inhibitor used for the treatment of rheumatoid arthritis. Currently approved by FDA in combination with remdesivir for treatment of COVID-19 hospitalized patient. Methods: The literature published pharmacokinetic parameters (Cl and Vd) of preclinical species (Rat, Dog and monkey) were utilized for the allometry scaling of Baricitinib. The connection among the primary pharmacokinetic parameters [Volume of distribution (Vd) and clearance (Cl)] and body weight (BW) were studied across three preclinical species, we used the double logarithmic plots for prediction of the human pharmacokinetic parameters i.e. Cl and Vd with use of simple allometry and with additional correction factors for better prediction. The dose extrapolation of baricitinib was carrie...
Asian Journal of Pharmacy and Pharmacology
JAK inhibitors block cytokine mediated signalling via the JAK-STAT pathway, which plays an import... more JAK inhibitors block cytokine mediated signalling via the JAK-STAT pathway, which plays an important role in immune regulation and growth. These 'small molecule' drugs are highly specific for blocking targets identified within cells that cause chronic inflammation. Rheumatoid arthritis (RA) is chronic autoimmune disorder characterized by severe destructive inflammation of the distal joints, particularly of the hands. The inflammation breaks down cartilage and bone, resulting in severe pain, stiffness, deformities, and disability. The inflammation can affect other areas as well, including the eyes, lungs, heart, or skin. RA can strike at any age but is more commonly seen in adulthood (Changelian et al., 2003). JAKs are intracellular enzymes that transmit signals from cytokines binding to receptors on the cell surface to signal transducers and activators of transcription (STATs), which drive pro-inflammatory cellular responses the JAK-STAT pathway. The JAK/STAT pathway: JAKs, named after the two-faced Roman God Janus, form a family consisting of four members: JAK1, JAK2, JAK3 and TYK2. They are all cytoplasmic tyrosine kinases able to phosphorylate tyrosine residues either on themselves (auto-phosphorylation) or on adjacent molecules (trans-phosphorylation), including the STATs. The latter is a family of transcription factors, acting downstream of JAKs and consisting of 7 members (O'Shea et al., 2013). Schematic representation of the various cytokines and their receptors signalling via the JAK/STAT Figure 1,. shows overview of the JAK-STAT signalling pathway. Binding of cytokines (yellow) to their receptors on the cell surface results in Janus kinase (JAK) activation and subsequent cross-phosphorylation of the receptors. Signal transducers and activators of transcription (STATs) then attach to the phosphorylated receptors, dimerize, and translocate to the nucleus where they drive the expression of proteins involved in inflammatory processes, including those leading to autoimmune diseases such as rheumatoid arthritis (Vashkiv and Hu, 2006). Methods The review of articles was done with articles published from 2003 to 2020 on JAK inhibitors which have clinical significance.
Journal of Medicinal Chemistry, 2021
The role of calcium release-activated calcium (CRAC) channels is well characterized and is of par... more The role of calcium release-activated calcium (CRAC) channels is well characterized and is of particular importance in T-cell function. CRAC channels are involved in the pathogenesis of several autoimmune diseases, making it an attractive therapeutic target for treating inflammatory diseases, like rheumatoid arthritis (RA). A systematic structure-activity relationship study with the goal of optimizing lipophilicity successfully yielded two lead compounds, 36 and 37. Both compounds showed decent potency and selectivity and a remarkable pharmacokinetic profile. Further characterization in in vivo RA models and subsequent histopathological evaluation of tissues led to the identification of 36 as a clinical candidate. Compound 36 displayed an excellent safety profile and had a sufficient safety margin to qualify it for use in human testing. Oral administration of 36 in Phase 1 clinical study in healthy volunteers established favorable safety, tolerability, and good target engagement as measured by levels of IL-2 and TNF-α.
Journal of Medicinal Chemistry, 2020
PI3Kδ inhibitors have been approved for B-cell malignancies like CLL, small lymphocytic lymphoma,... more PI3Kδ inhibitors have been approved for B-cell malignancies like CLL, small lymphocytic lymphoma, and so forth. However, currently available PI3Kδ inhibitors are nonoptimal, showing weakness against at least one of the several important properties: potency, isoform selectivity, and/or pharmacokinetic profile. To come up with a PI3Kδ inhibitor that overcomes all these deficiencies, a pharmacophoric expansion strategy was employed. Herein, we describe a systematic transformation of a "three-blade propeller" shaped lead, 2,3-disubstituted quinolizinone 11, through a 1,2-disubstituted quinolizinone 20 to a novel "four-blade propeller" shaped 1,2,3-trisubstituted quinolizinone 34. Compound 34 has excellent potency, isoform selectivity, metabolic stability across species, and exhibited a favorable pharmacokinetic profile. Compound 34 also demonstrated a differentiated efficacy profile in human germinal center B and activated B cell-DLBCL cell lines and xenograft models. Compound 34 qualifies for further evaluation as a candidate for monotherapy or in combination with other targeted agents in DLBCLs and other forms of iNHL.
Bioorganic & Medicinal Chemistry, 2020
The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I &a... more The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I & II) and naphthyridinone (III) analogues is described. Compounds of structure I have good biochemical and cellular potency but suffered from inferior PK. Constraining the linear propylene linker of structure I into a cyclopentene ring (II) offered improved PK parameters, while maintaining potency for PARP1. Finally, to avoid potential issues that may arise from the presence of an anilinic moiety, the nitrogen substituent on the isoquinolinone ring was incorporated as part of the bicyclic ring. This afforded a naphthyridinone scaffold, as shown in structure III. Further optimization of naphthyridinone series led to identification of a novel and highly potent PARP1 inhibitor 34, which was further characterized as preclinical candidate molecule. Compound 34 is orally bioavailable and displayed favorable pharmacokinetic (PK) properties. Compound 34 demonstrated remarkable antitumor efficacy both as a single-agent as well as in combination with chemotherapeutic agents in the BRCA1 mutant MDA-MB-436 breast cancer xenograft model. Additionally, compound 34 also potentiated the effect of agents such as temozolomide in breast cancer, pancreatic cancer and Ewing's sarcoma models.
Journal of Medicinal Chemistry, 2019
The identification of a novel class of potent pan-genotypic NS5A inhibitors with good pharmacokin... more The identification of a novel class of potent pan-genotypic NS5A inhibitors with good pharmacokinetic profile suitable for potential use in treating HCV infections is disclosed here. The present series of compounds are with less complex tricyclic central core, identified through a systematic SAR study carried out on biphenyl moiety. The SAR outcome has confirmed the requirement of near planar and linear conformation of the molecule to achieve the best pangenotypic activity. In addition, SAR with substituted imidazoles on improvement of antiviral activity is disclosed. The newly identified compounds 12, 16, 19−21 have shown desirable pharmacokinetic profiles with a favorable uptake of compounds in liver and maintained a significant concentration for up to 8 h in the liver. In addition, compounds 20 and 21 have shown superior pan-genotypic anti-HCV activity compared to ledipasvir and daclatasvir. Additional characterization and preliminary safety assessment resulted in the identification of compound 20 as a potential clinical candidate.
Xenobiotica, 2019
Uptake and pharmacokinetics of cefuroxime in rabbits after intravitreal, intracameral and topical... more Uptake and pharmacokinetics of cefuroxime in rabbits after intravitreal, intracameral and topical dosing-Relevance to human ocular injection of cefuroxime
Drug Research, 2018
Bendamustine, an alkylating anticancer agent, is used to treat chronic lymphocytic leukemia by in... more Bendamustine, an alkylating anticancer agent, is used to treat chronic lymphocytic leukemia by intravenous infusion alone or in combination. The work aimed to develop a method to predict time vs. concentration profile for humans based on preclinical pharmacokinetics using the assumption of superimposability of normalized time course profiles of animals and humans. Standard allometric equations with/without correction factors (CF) were also used in prediction. The Vss was predicted by simple allometry of 0.312W0.871 (r2=0.987), where W is body weight; predicted Vss (19.71 L) was similar to the reported value (20.10 L). However, CL prediction involved both simple and CF allometry. Best proximity CL (543 vs. 598 mL/min) was obtained with maximum life span correction (MLP) [2.46W1.215 (r2=0.988)]. Normalized curves were obtained by normalizing the time (with mean residence time) vs. concentration (with dose/Vss) in animal species. The concentration vs. time profile in humans after intra...
Drug research, Jan 7, 2018
A simple, sensitive and rapid assay method has been developed and validated as per regulatory gui... more A simple, sensitive and rapid assay method has been developed and validated as per regulatory guideline for the estimation of tofacitinib on mice dried blood spots (DBS) using liquid chromatography coupled to tandem mass spectrometry with electro spray ionization in the positive-ion mode. The method employs liquid extraction of tofacitinib from DBS disk of mice whole blood followed by chromatographic separation using 5 mM ammonium acetate (pH 6.5):acetonitrile (20:80, v/v) at a flow rate of 0.60 mL/min on an X-Terra Phenyl column with a total run time 2.5 min. The MS/MS ion transitions monitored were 313→149 for tofacitinib and 316→149 for the internal standard (CN-tofacitinib). The assay was linear in the range of 0.99-1980 ng/mL. The intra- and inter-day precision was in the range of 1.17-10.3 and 3.37-10.9%, respectively. Stability studies showed that tofacitinib was stable on DBS cards for one month. This novel method has been applied to analyze the DBS samples of tofacitinib ob...
Journal of Pharmaceutical and Biomedical Analysis, 2017
Highlights First LC-MS/MS method being reported for the simultaneous quantification of daroluta... more Highlights First LC-MS/MS method being reported for the simultaneous quantification of darolutamide and ORM-15341 in mice plasma. Simple sample processing method and shorter run time (2.5 min) enables this method as a high throughput assay. Method was validated as per regulatory guidelines. The method is specific, precise, accurate and no matrix effect was observed and linear from 0.61-1097 ng/mL for both the analytes.
Indian Journal of Pharmaceutical Sciences, 2010
Nagare, et al.: Determination of Site of Propranolol Absorption in Rat Gut Previously, permeabili... more Nagare, et al.: Determination of Site of Propranolol Absorption in Rat Gut Previously, permeability and site of intestinal absorption of propranolol have been reported using the Ussing chamber. In the present study, the utility of Single-Pass Intestinal Perfusion to study permeability and site of intestinal absorption of propranolol was evaluated in rats. Drug permeability in different regions of rat intestine viz. duodenum, jejunum, ileum and colon was measured. Propranolol (30 μg/ml) solution was perfused in situ in each intestinal segment of rats. Effective permeability (Peff) of propranolol in each segment was calculated and site of absorption was determined. The Peff of propranolol in rat duodenum, jejunum, ileum and colon was calculated to be 0.3316×10-4 cm/s, 0.4035×10-4 cm/s, 0.5092×10-4 cm/s and 0.7167×10-4 cm/s, respectively. The above results suggest that permeability of propranolol was highest through colon compared to other intestinal sites, which is in close agreement to that reported previously. In conclusion, in situ single pass intestinal perfusion can be used effectively to study intestinal permeability as well as site of intestinal absorption of compounds in rats.
Indian Journal of Pharmaceutical Sciences, 2009
Damre et al.: Preparation and Characterization of Rodent Intestinal Microsomes Small intestine pl... more Damre et al.: Preparation and Characterization of Rodent Intestinal Microsomes Small intestine plays an important role in the first-pass metabolism of orally ingested xenobiotics as a result of expression of both Phase I and Phase II metabolic enzymes, together with associated transporters. Intestinal microsomes thus can be used to study susceptibility of compounds to metabolism in vitro. The present study was undertaken to have a comparative assessment between different methods of preparation of rodent intestinal microsomes. Mouse and rat intestinal microsomes were prepared by two methods, in method A intestines were homogenized, while in method B mucosal cells were scrapped followed by homogenization. Further, microsomes were prepared by centrifugation (10000×g) followed by ultra centrifugation (100000×g) of the homogenates. The prepared microsomes were characterized for protein concentration using Bradford's method and CYP450 content using carbon monoxide bubbling method. The protein concentration and CYP450 content in microsomes prepared by method B was significantly higher than method A. In conclusion, superior quality intestinal microsomes can be obtained from rodents by using scrapped intestinal mucosal cells as compared to the intestinal homogenates.
Journal of Chromatography B, 2014
A selective, sensitive and rapid mice dried blood spot (DBS) method has been developed and valida... more A selective, sensitive and rapid mice dried blood spot (DBS) method has been developed and validated for the simultaneous quantification of bendamustine (BM) and ␥-hydroxy-bendamustine (HBM) as per regulatory guidelines using an LC-MS/MS. Quality control, calibration curve and study sample DBS cards were sonicated with 5% formic acid in water before extraction with ethyl acetate enriched with internal standard (I.S.). The organic layer was evaporated and residue was reconstituted in 0.1% formic acid in acetonitrile for LC-MS/MS analysis. Chromatographic resolution of both analytes (BM and HBM) and the I.S. (loperamide) was achieved on an Atlantis dC 18 column using 0.2% formic acid:acetonitrile (25:75, v/v) as an eluant delivered at a constant flow-rate of 0.5 mL/min. The total chromatographic run time was 3.2 min. The MS/MS ion transitions monitored were m/z 358.0 → 228.0, 374.0 → 338.0 and 477.0 → 210.0 for BM, HBM and the I.S, respectively. The assay was linear in the range of 5.65-2544 ng/mL for both BM and HBM. The within-run and between-run accuracy and within-run and between-run precision were in the range of 0.96-1.00 and 1.36-9.94%, respectively for BM; 0.88-1.03 and 4.57-11.7%, respectively for HBM on mice DBS cards. Stability studies showed that both analytes were stable at room temperature for 7 days and at −80 • C for 55 days on DBS cards. The validated DBS method has been applied to a pharmacokinetic study in mice.
Biomedical Chromatography
AMG 510 is the first-in-class KRASG12C inhibitor, currently entering into Phase-2 clinical trials... more AMG 510 is the first-in-class KRASG12C inhibitor, currently entering into Phase-2 clinical trials as an orphan drug to treat non-small cell lung cancer patients. We developed and validated a sensitive, selective and high-throughput HPLC-MS/MS (liquid chromatography with tandem mass spectrometry) method for the quantitation of AMG 510 in mouse plasma as per the FDA regulatory guideline. AMG 510 and the IS (MRTX-1257) were extracted from mouse plasma using tert-butyl methyl ether and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 25:75, v/v) at a flow-rate of 0.65 mL/min on an Atlantis dC18 column. AMG 510 and the IS eluted at ~0.95 and 0.73 min, respectively. AMG 510 and the IS were detected by positive electro-spray ionization in multiple reaction monitoring using transition pair (Q1→Q3) m/z 561.1→134.1 and m/z 566.5→ 98.2, respectively. Excellent linearity was achieved in the concentration range of 1.08-5040 ng/mL (r >0.0996). No matrix effect and carry over were observed. Intra- and inter-day accuracies and precisions were within the acceptance range. AMG 510 was demonstrated to be stable under the tested storage conditions. This novel method has been applied to a pharmacokinetic study in mice.
AAPS PharmSciTech
Fomepizole is used as an antidote to treat methanol poisoning due to its selectivity towards alco... more Fomepizole is used as an antidote to treat methanol poisoning due to its selectivity towards alcohol dehydrogenase. In the present study, the goal is to develop a method to predict the fomepizole human plasma concentration versus time profile based on the preclinical pharmacokinetics using the assumption of superimposability on simulated time course profiles of animals and humans. Standard allometric equations with/without correction factors were also assimilated in the prediction. The volume of distribution at steady state (Vss) predicted by simple allometry (57.55 L) was very close to the reported value (42.17 L). However, clearance (CL) prediction by simple allometry was at least 3-fold higher to the reported value (33.86 mL/min); hence, multiple correction factors were used to predict the clearance. Both brain weight and maximum life span potential could predict the CL with 1.22- and 1.01-fold difference. Specifically, the predicted Vss and CL values via interspecies scaling were used in the prediction of series of human intravenous pharmacokinetic parameters, while the simulation of human oral profile was done by the use of absorption rate constant (Ka) from dog following the applicability of human bioavailability value scaled from dog data. In summary, the findings indicate that the utility of diverse allometry approaches to derive the human pharmacokinetics of fomepizole after intravenous/oral dosing.
ADMET and DMPK
A simple, selective and rapid LC-ESI-MS/MS method has been developed and validated for the quanti... more A simple, selective and rapid LC-ESI-MS/MS method has been developed and validated for the quantification of ivosidenib in mice plasma using warfarin as an internal standard (I.S.) as per regulatory guideline. Sample preparation was accomplished through a simple protein precipitation process. Chromatography of ivosidenib and the I.S. was achieved on an Atlantis dC 18 column using an isocratic mobile phase comprising 0.2 % formic acid in water and acetonitrile (25:75, v/v) delivered at a flow rate of 1.0 mL/min. LC-MS/MS was operated under the multiple reaction-monitoring mode (MRM) using the electrospray ionization technique in positive ion mode and the transitions of m/z 583.1→186.1 and m/z 309.2→251.3 were used to quantitate ivosidenib and the I.S, respectively. The total chromatographic run time was 2.0 min. Linearity was established in the concentration range of 1.10-3293 ng/mL (r 2 >0.99). The intra-and inter-day accuracy and precision for ivosidenib in mice plasma were in the range of 5.72-9.91 and 5.90-10.7 %, respectively. Ivosidenib was found to be stable on bench-top for 6 h, up to three freeze-thaw cycles, in in-injector for 24 h and for one month at-80 °C. The applicability of the validated method has been demonstrated in a mice pharmacokinetic study. Following intravenous (2 mg/kg) and oral (5 mg/kg) administration of ivosidenib to mice, concentrations were quantifiable up to 24 and 48 h, respectively. The bioavailability was 61 %.
Indian Journal of Pharmaceutical Sciences, 2010
Previously, permeability and site of intestinal absorption of propranolol have been reported usin... more Previously, permeability and site of intestinal absorption of propranolol have been reported using the Ussing chamber. In the present study, the utility of Single-Pass Intestinal Perfusion to study permeability and site of intestinal absorption of propranolol was evaluated in rats. Drug permeability in different regions of rat intestine viz. duodenum, jejunum, ileum and colon was measured. Propranolol (30 μg/ml) solution was perfused in situ in each intestinal segment of rats. Effective permeability (Peff) of propranolol in each segment was calculated and site of absorption was determined. The Peff of propranolol in rat duodenum, jejunum, ileum and colon was calculated to be 0.3316×10(-4) cm/s, 0.4035×10(-4)cm/s, 0.5092×10(-4) cm/s and 0.7167×10(-4) cm/s, respectively. The above results suggest that permeability of propranolol was highest through colon compared to other intestinal sites, which is in close agreement to that reported previously. In conclusion, in situ single pass intestinal perfusion can be used effectively to study intestinal permeability as well as site of intestinal absorption of compounds in rats.
Indian Journal of Pharmaceutical Sciences, 2009
Small intestine plays an important role in the first-pass metabolism of orally ingested xenobioti... more Small intestine plays an important role in the first-pass metabolism of orally ingested xenobiotics as a result of expression of both Phase I and Phase II metabolic enzymes, together with associated transporters. Intestinal microsomes thus can be used to study susceptibility of compounds to metabolism in vitro. The present study was undertaken to have a comparative assessment between different methods of preparation of rodent intestinal microsomes. Mouse and rat intestinal microsomes were prepared by two methods, in method A intestines were homogenized, while in method B mucosal cells were scrapped followed by homogenization. Further, microsomes were prepared by centrifugation (10000×g) followed by ultra centrifugation (100000×g) of the homogenates. The prepared microsomes were characterized for protein concentration using Bradford's method and CYP450 content using carbon monoxide bubbling method. The protein concentration and CYP450 content in microsomes prepared by method B was significantly higher than method A. In conclusion, superior quality intestinal microsomes can be obtained from rodents by using scrapped intestinal mucosal cells as compared to the intestinal homogenates.
Biomedical and Pharmacology Journal
Purpose: The primary motive of this study was to examine advantages of allometry scaling strategi... more Purpose: The primary motive of this study was to examine advantages of allometry scaling strategies for correct prediction of pharmacokinetics of Baricitinib in human from preclinical species. Baricitinib is basically Janus kinase (JAK) inhibitor used for the treatment of rheumatoid arthritis. Currently approved by FDA in combination with remdesivir for treatment of COVID-19 hospitalized patient. Methods: The literature published pharmacokinetic parameters (Cl and Vd) of preclinical species (Rat, Dog and monkey) were utilized for the allometry scaling of Baricitinib. The connection among the primary pharmacokinetic parameters [Volume of distribution (Vd) and clearance (Cl)] and body weight (BW) were studied across three preclinical species, we used the double logarithmic plots for prediction of the human pharmacokinetic parameters i.e. Cl and Vd with use of simple allometry and with additional correction factors for better prediction. The dose extrapolation of baricitinib was carrie...
Asian Journal of Pharmacy and Pharmacology
JAK inhibitors block cytokine mediated signalling via the JAK-STAT pathway, which plays an import... more JAK inhibitors block cytokine mediated signalling via the JAK-STAT pathway, which plays an important role in immune regulation and growth. These 'small molecule' drugs are highly specific for blocking targets identified within cells that cause chronic inflammation. Rheumatoid arthritis (RA) is chronic autoimmune disorder characterized by severe destructive inflammation of the distal joints, particularly of the hands. The inflammation breaks down cartilage and bone, resulting in severe pain, stiffness, deformities, and disability. The inflammation can affect other areas as well, including the eyes, lungs, heart, or skin. RA can strike at any age but is more commonly seen in adulthood (Changelian et al., 2003). JAKs are intracellular enzymes that transmit signals from cytokines binding to receptors on the cell surface to signal transducers and activators of transcription (STATs), which drive pro-inflammatory cellular responses the JAK-STAT pathway. The JAK/STAT pathway: JAKs, named after the two-faced Roman God Janus, form a family consisting of four members: JAK1, JAK2, JAK3 and TYK2. They are all cytoplasmic tyrosine kinases able to phosphorylate tyrosine residues either on themselves (auto-phosphorylation) or on adjacent molecules (trans-phosphorylation), including the STATs. The latter is a family of transcription factors, acting downstream of JAKs and consisting of 7 members (O'Shea et al., 2013). Schematic representation of the various cytokines and their receptors signalling via the JAK/STAT Figure 1,. shows overview of the JAK-STAT signalling pathway. Binding of cytokines (yellow) to their receptors on the cell surface results in Janus kinase (JAK) activation and subsequent cross-phosphorylation of the receptors. Signal transducers and activators of transcription (STATs) then attach to the phosphorylated receptors, dimerize, and translocate to the nucleus where they drive the expression of proteins involved in inflammatory processes, including those leading to autoimmune diseases such as rheumatoid arthritis (Vashkiv and Hu, 2006). Methods The review of articles was done with articles published from 2003 to 2020 on JAK inhibitors which have clinical significance.
Journal of Medicinal Chemistry, 2021
The role of calcium release-activated calcium (CRAC) channels is well characterized and is of par... more The role of calcium release-activated calcium (CRAC) channels is well characterized and is of particular importance in T-cell function. CRAC channels are involved in the pathogenesis of several autoimmune diseases, making it an attractive therapeutic target for treating inflammatory diseases, like rheumatoid arthritis (RA). A systematic structure-activity relationship study with the goal of optimizing lipophilicity successfully yielded two lead compounds, 36 and 37. Both compounds showed decent potency and selectivity and a remarkable pharmacokinetic profile. Further characterization in in vivo RA models and subsequent histopathological evaluation of tissues led to the identification of 36 as a clinical candidate. Compound 36 displayed an excellent safety profile and had a sufficient safety margin to qualify it for use in human testing. Oral administration of 36 in Phase 1 clinical study in healthy volunteers established favorable safety, tolerability, and good target engagement as measured by levels of IL-2 and TNF-α.
Journal of Medicinal Chemistry, 2020
PI3Kδ inhibitors have been approved for B-cell malignancies like CLL, small lymphocytic lymphoma,... more PI3Kδ inhibitors have been approved for B-cell malignancies like CLL, small lymphocytic lymphoma, and so forth. However, currently available PI3Kδ inhibitors are nonoptimal, showing weakness against at least one of the several important properties: potency, isoform selectivity, and/or pharmacokinetic profile. To come up with a PI3Kδ inhibitor that overcomes all these deficiencies, a pharmacophoric expansion strategy was employed. Herein, we describe a systematic transformation of a "three-blade propeller" shaped lead, 2,3-disubstituted quinolizinone 11, through a 1,2-disubstituted quinolizinone 20 to a novel "four-blade propeller" shaped 1,2,3-trisubstituted quinolizinone 34. Compound 34 has excellent potency, isoform selectivity, metabolic stability across species, and exhibited a favorable pharmacokinetic profile. Compound 34 also demonstrated a differentiated efficacy profile in human germinal center B and activated B cell-DLBCL cell lines and xenograft models. Compound 34 qualifies for further evaluation as a candidate for monotherapy or in combination with other targeted agents in DLBCLs and other forms of iNHL.
Bioorganic & Medicinal Chemistry, 2020
The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I &a... more The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I & II) and naphthyridinone (III) analogues is described. Compounds of structure I have good biochemical and cellular potency but suffered from inferior PK. Constraining the linear propylene linker of structure I into a cyclopentene ring (II) offered improved PK parameters, while maintaining potency for PARP1. Finally, to avoid potential issues that may arise from the presence of an anilinic moiety, the nitrogen substituent on the isoquinolinone ring was incorporated as part of the bicyclic ring. This afforded a naphthyridinone scaffold, as shown in structure III. Further optimization of naphthyridinone series led to identification of a novel and highly potent PARP1 inhibitor 34, which was further characterized as preclinical candidate molecule. Compound 34 is orally bioavailable and displayed favorable pharmacokinetic (PK) properties. Compound 34 demonstrated remarkable antitumor efficacy both as a single-agent as well as in combination with chemotherapeutic agents in the BRCA1 mutant MDA-MB-436 breast cancer xenograft model. Additionally, compound 34 also potentiated the effect of agents such as temozolomide in breast cancer, pancreatic cancer and Ewing's sarcoma models.
Journal of Medicinal Chemistry, 2019
The identification of a novel class of potent pan-genotypic NS5A inhibitors with good pharmacokin... more The identification of a novel class of potent pan-genotypic NS5A inhibitors with good pharmacokinetic profile suitable for potential use in treating HCV infections is disclosed here. The present series of compounds are with less complex tricyclic central core, identified through a systematic SAR study carried out on biphenyl moiety. The SAR outcome has confirmed the requirement of near planar and linear conformation of the molecule to achieve the best pangenotypic activity. In addition, SAR with substituted imidazoles on improvement of antiviral activity is disclosed. The newly identified compounds 12, 16, 19−21 have shown desirable pharmacokinetic profiles with a favorable uptake of compounds in liver and maintained a significant concentration for up to 8 h in the liver. In addition, compounds 20 and 21 have shown superior pan-genotypic anti-HCV activity compared to ledipasvir and daclatasvir. Additional characterization and preliminary safety assessment resulted in the identification of compound 20 as a potential clinical candidate.
Xenobiotica, 2019
Uptake and pharmacokinetics of cefuroxime in rabbits after intravitreal, intracameral and topical... more Uptake and pharmacokinetics of cefuroxime in rabbits after intravitreal, intracameral and topical dosing-Relevance to human ocular injection of cefuroxime
Drug Research, 2018
Bendamustine, an alkylating anticancer agent, is used to treat chronic lymphocytic leukemia by in... more Bendamustine, an alkylating anticancer agent, is used to treat chronic lymphocytic leukemia by intravenous infusion alone or in combination. The work aimed to develop a method to predict time vs. concentration profile for humans based on preclinical pharmacokinetics using the assumption of superimposability of normalized time course profiles of animals and humans. Standard allometric equations with/without correction factors (CF) were also used in prediction. The Vss was predicted by simple allometry of 0.312W0.871 (r2=0.987), where W is body weight; predicted Vss (19.71 L) was similar to the reported value (20.10 L). However, CL prediction involved both simple and CF allometry. Best proximity CL (543 vs. 598 mL/min) was obtained with maximum life span correction (MLP) [2.46W1.215 (r2=0.988)]. Normalized curves were obtained by normalizing the time (with mean residence time) vs. concentration (with dose/Vss) in animal species. The concentration vs. time profile in humans after intra...
Drug research, Jan 7, 2018
A simple, sensitive and rapid assay method has been developed and validated as per regulatory gui... more A simple, sensitive and rapid assay method has been developed and validated as per regulatory guideline for the estimation of tofacitinib on mice dried blood spots (DBS) using liquid chromatography coupled to tandem mass spectrometry with electro spray ionization in the positive-ion mode. The method employs liquid extraction of tofacitinib from DBS disk of mice whole blood followed by chromatographic separation using 5 mM ammonium acetate (pH 6.5):acetonitrile (20:80, v/v) at a flow rate of 0.60 mL/min on an X-Terra Phenyl column with a total run time 2.5 min. The MS/MS ion transitions monitored were 313→149 for tofacitinib and 316→149 for the internal standard (CN-tofacitinib). The assay was linear in the range of 0.99-1980 ng/mL. The intra- and inter-day precision was in the range of 1.17-10.3 and 3.37-10.9%, respectively. Stability studies showed that tofacitinib was stable on DBS cards for one month. This novel method has been applied to analyze the DBS samples of tofacitinib ob...
Journal of Pharmaceutical and Biomedical Analysis, 2017
Highlights First LC-MS/MS method being reported for the simultaneous quantification of daroluta... more Highlights First LC-MS/MS method being reported for the simultaneous quantification of darolutamide and ORM-15341 in mice plasma. Simple sample processing method and shorter run time (2.5 min) enables this method as a high throughput assay. Method was validated as per regulatory guidelines. The method is specific, precise, accurate and no matrix effect was observed and linear from 0.61-1097 ng/mL for both the analytes.
Indian Journal of Pharmaceutical Sciences, 2010
Nagare, et al.: Determination of Site of Propranolol Absorption in Rat Gut Previously, permeabili... more Nagare, et al.: Determination of Site of Propranolol Absorption in Rat Gut Previously, permeability and site of intestinal absorption of propranolol have been reported using the Ussing chamber. In the present study, the utility of Single-Pass Intestinal Perfusion to study permeability and site of intestinal absorption of propranolol was evaluated in rats. Drug permeability in different regions of rat intestine viz. duodenum, jejunum, ileum and colon was measured. Propranolol (30 μg/ml) solution was perfused in situ in each intestinal segment of rats. Effective permeability (Peff) of propranolol in each segment was calculated and site of absorption was determined. The Peff of propranolol in rat duodenum, jejunum, ileum and colon was calculated to be 0.3316×10-4 cm/s, 0.4035×10-4 cm/s, 0.5092×10-4 cm/s and 0.7167×10-4 cm/s, respectively. The above results suggest that permeability of propranolol was highest through colon compared to other intestinal sites, which is in close agreement to that reported previously. In conclusion, in situ single pass intestinal perfusion can be used effectively to study intestinal permeability as well as site of intestinal absorption of compounds in rats.
Indian Journal of Pharmaceutical Sciences, 2009
Damre et al.: Preparation and Characterization of Rodent Intestinal Microsomes Small intestine pl... more Damre et al.: Preparation and Characterization of Rodent Intestinal Microsomes Small intestine plays an important role in the first-pass metabolism of orally ingested xenobiotics as a result of expression of both Phase I and Phase II metabolic enzymes, together with associated transporters. Intestinal microsomes thus can be used to study susceptibility of compounds to metabolism in vitro. The present study was undertaken to have a comparative assessment between different methods of preparation of rodent intestinal microsomes. Mouse and rat intestinal microsomes were prepared by two methods, in method A intestines were homogenized, while in method B mucosal cells were scrapped followed by homogenization. Further, microsomes were prepared by centrifugation (10000×g) followed by ultra centrifugation (100000×g) of the homogenates. The prepared microsomes were characterized for protein concentration using Bradford's method and CYP450 content using carbon monoxide bubbling method. The protein concentration and CYP450 content in microsomes prepared by method B was significantly higher than method A. In conclusion, superior quality intestinal microsomes can be obtained from rodents by using scrapped intestinal mucosal cells as compared to the intestinal homogenates.
Journal of Chromatography B, 2014
A selective, sensitive and rapid mice dried blood spot (DBS) method has been developed and valida... more A selective, sensitive and rapid mice dried blood spot (DBS) method has been developed and validated for the simultaneous quantification of bendamustine (BM) and ␥-hydroxy-bendamustine (HBM) as per regulatory guidelines using an LC-MS/MS. Quality control, calibration curve and study sample DBS cards were sonicated with 5% formic acid in water before extraction with ethyl acetate enriched with internal standard (I.S.). The organic layer was evaporated and residue was reconstituted in 0.1% formic acid in acetonitrile for LC-MS/MS analysis. Chromatographic resolution of both analytes (BM and HBM) and the I.S. (loperamide) was achieved on an Atlantis dC 18 column using 0.2% formic acid:acetonitrile (25:75, v/v) as an eluant delivered at a constant flow-rate of 0.5 mL/min. The total chromatographic run time was 3.2 min. The MS/MS ion transitions monitored were m/z 358.0 → 228.0, 374.0 → 338.0 and 477.0 → 210.0 for BM, HBM and the I.S, respectively. The assay was linear in the range of 5.65-2544 ng/mL for both BM and HBM. The within-run and between-run accuracy and within-run and between-run precision were in the range of 0.96-1.00 and 1.36-9.94%, respectively for BM; 0.88-1.03 and 4.57-11.7%, respectively for HBM on mice DBS cards. Stability studies showed that both analytes were stable at room temperature for 7 days and at −80 • C for 55 days on DBS cards. The validated DBS method has been applied to a pharmacokinetic study in mice.
Biomedical Chromatography
AMG 510 is the first-in-class KRASG12C inhibitor, currently entering into Phase-2 clinical trials... more AMG 510 is the first-in-class KRASG12C inhibitor, currently entering into Phase-2 clinical trials as an orphan drug to treat non-small cell lung cancer patients. We developed and validated a sensitive, selective and high-throughput HPLC-MS/MS (liquid chromatography with tandem mass spectrometry) method for the quantitation of AMG 510 in mouse plasma as per the FDA regulatory guideline. AMG 510 and the IS (MRTX-1257) were extracted from mouse plasma using tert-butyl methyl ether and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 25:75, v/v) at a flow-rate of 0.65 mL/min on an Atlantis dC18 column. AMG 510 and the IS eluted at ~0.95 and 0.73 min, respectively. AMG 510 and the IS were detected by positive electro-spray ionization in multiple reaction monitoring using transition pair (Q1→Q3) m/z 561.1→134.1 and m/z 566.5→ 98.2, respectively. Excellent linearity was achieved in the concentration range of 1.08-5040 ng/mL (r >0.0996). No matrix effect and carry over were observed. Intra- and inter-day accuracies and precisions were within the acceptance range. AMG 510 was demonstrated to be stable under the tested storage conditions. This novel method has been applied to a pharmacokinetic study in mice.
AAPS PharmSciTech
Fomepizole is used as an antidote to treat methanol poisoning due to its selectivity towards alco... more Fomepizole is used as an antidote to treat methanol poisoning due to its selectivity towards alcohol dehydrogenase. In the present study, the goal is to develop a method to predict the fomepizole human plasma concentration versus time profile based on the preclinical pharmacokinetics using the assumption of superimposability on simulated time course profiles of animals and humans. Standard allometric equations with/without correction factors were also assimilated in the prediction. The volume of distribution at steady state (Vss) predicted by simple allometry (57.55 L) was very close to the reported value (42.17 L). However, clearance (CL) prediction by simple allometry was at least 3-fold higher to the reported value (33.86 mL/min); hence, multiple correction factors were used to predict the clearance. Both brain weight and maximum life span potential could predict the CL with 1.22- and 1.01-fold difference. Specifically, the predicted Vss and CL values via interspecies scaling were used in the prediction of series of human intravenous pharmacokinetic parameters, while the simulation of human oral profile was done by the use of absorption rate constant (Ka) from dog following the applicability of human bioavailability value scaled from dog data. In summary, the findings indicate that the utility of diverse allometry approaches to derive the human pharmacokinetics of fomepizole after intravenous/oral dosing.
ADMET and DMPK
A simple, selective and rapid LC-ESI-MS/MS method has been developed and validated for the quanti... more A simple, selective and rapid LC-ESI-MS/MS method has been developed and validated for the quantification of ivosidenib in mice plasma using warfarin as an internal standard (I.S.) as per regulatory guideline. Sample preparation was accomplished through a simple protein precipitation process. Chromatography of ivosidenib and the I.S. was achieved on an Atlantis dC 18 column using an isocratic mobile phase comprising 0.2 % formic acid in water and acetonitrile (25:75, v/v) delivered at a flow rate of 1.0 mL/min. LC-MS/MS was operated under the multiple reaction-monitoring mode (MRM) using the electrospray ionization technique in positive ion mode and the transitions of m/z 583.1→186.1 and m/z 309.2→251.3 were used to quantitate ivosidenib and the I.S, respectively. The total chromatographic run time was 2.0 min. Linearity was established in the concentration range of 1.10-3293 ng/mL (r 2 >0.99). The intra-and inter-day accuracy and precision for ivosidenib in mice plasma were in the range of 5.72-9.91 and 5.90-10.7 %, respectively. Ivosidenib was found to be stable on bench-top for 6 h, up to three freeze-thaw cycles, in in-injector for 24 h and for one month at-80 °C. The applicability of the validated method has been demonstrated in a mice pharmacokinetic study. Following intravenous (2 mg/kg) and oral (5 mg/kg) administration of ivosidenib to mice, concentrations were quantifiable up to 24 and 48 h, respectively. The bioavailability was 61 %.
Indian Journal of Pharmaceutical Sciences, 2010
Previously, permeability and site of intestinal absorption of propranolol have been reported usin... more Previously, permeability and site of intestinal absorption of propranolol have been reported using the Ussing chamber. In the present study, the utility of Single-Pass Intestinal Perfusion to study permeability and site of intestinal absorption of propranolol was evaluated in rats. Drug permeability in different regions of rat intestine viz. duodenum, jejunum, ileum and colon was measured. Propranolol (30 μg/ml) solution was perfused in situ in each intestinal segment of rats. Effective permeability (Peff) of propranolol in each segment was calculated and site of absorption was determined. The Peff of propranolol in rat duodenum, jejunum, ileum and colon was calculated to be 0.3316×10(-4) cm/s, 0.4035×10(-4)cm/s, 0.5092×10(-4) cm/s and 0.7167×10(-4) cm/s, respectively. The above results suggest that permeability of propranolol was highest through colon compared to other intestinal sites, which is in close agreement to that reported previously. In conclusion, in situ single pass intestinal perfusion can be used effectively to study intestinal permeability as well as site of intestinal absorption of compounds in rats.
Indian Journal of Pharmaceutical Sciences, 2009
Small intestine plays an important role in the first-pass metabolism of orally ingested xenobioti... more Small intestine plays an important role in the first-pass metabolism of orally ingested xenobiotics as a result of expression of both Phase I and Phase II metabolic enzymes, together with associated transporters. Intestinal microsomes thus can be used to study susceptibility of compounds to metabolism in vitro. The present study was undertaken to have a comparative assessment between different methods of preparation of rodent intestinal microsomes. Mouse and rat intestinal microsomes were prepared by two methods, in method A intestines were homogenized, while in method B mucosal cells were scrapped followed by homogenization. Further, microsomes were prepared by centrifugation (10000×g) followed by ultra centrifugation (100000×g) of the homogenates. The prepared microsomes were characterized for protein concentration using Bradford's method and CYP450 content using carbon monoxide bubbling method. The protein concentration and CYP450 content in microsomes prepared by method B was significantly higher than method A. In conclusion, superior quality intestinal microsomes can be obtained from rodents by using scrapped intestinal mucosal cells as compared to the intestinal homogenates.