Manu Jaggi

Dabur Research Foundation, Ghazibad, Uttar Pradesh, India

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Publications (47)105.27 Total impact

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    ABSTRACT: Multidrug resistance (MDR) is an area of concern for the drug developers as well as clinical practitioners. This phenomenon is putting an emance pressure on treatment modalities of many diseases as well as posing a grave danger over clinically accepted drugs as well as molecules under clinical development. P-glycoprotein (P-gp) mediated efflux of xenobiotics is one of the major mechanisms involved in MDR. Hence, an effective modulation of P-gp may restore the potential of many substrate drugs. However, the non-specific P-gp modulation may be associated with many unwanted toxic effects. Therefore, an approach involving simultaneous exploitation of P-gp modulation as well as targeted delivery in a particulate carrier system may result in a more effective MDR reversal, accompanying a safer drug profile.
    Medical Hypotheses 12/2013; · 1.18 Impact Factor
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    ABSTRACT: The present study investigates the screening of the formulation components as well as evaluates the quality issues of the nanostructured lipid carriers (NLCs) for the anticancer agent, CPT-11. The Stepwise screening of the components for the preparation of NLCs requires the selection of liquid lipid or oil, based on the relative solubility of CPT-11 in different oils. Maximum solubility of the CPT-11 was found in capmul MCM-C8 (81± 0.5mg/ml). Hence, it was selected as the liquid lipid for the development of NLCs. Solid lipids gelucire 39/1, glyceryl mono stearate (GSM) and compritol ATO 888 were observed to have good affinity for the drug on systematic screening of different solid lipids. However, gelucire 39/1 and GSM were found to have lower physical compatibility (miscibility) with capmul MCM C-8. Hence, compritol ATO 888 was selected as the solid lipid phase for the preparation of NLCs. Ratio of liquid lipid (oil) to solid lipid was optimized with the intention of maximizing the oil concentration (as oil was found to have higher solubility of drug) as well as producing a lipid mix with sufficient melting point to maintain solid state. The liquid-solid lipid mixture in the ratio up to 30:70 was observed to have sufficient melting point (52.48±1.2°C). Pluronic F-68 was selected as the main surfactant for the preparation of NLCs because of its good emulsification efficacy for the solid lipid liquid mix. The optimized formulation was also evaluated for the different quality issues. PXRD data revealed that the characteristic peaks of the compritol were present in the NLC samples and there was no appreciable polymorphic change when the formulation was stored for 6 months. Electron microscopic and DLS studies proved the absence of different colloidal species. Thermal analysis by DSC revealed that the lipid particles maintained sufficiently good melting point even after nanosizing. Absence of gelation on multiple syringing and resilience for the stress provided by autoclaving further established the quality of the developed NLCs.
    International Journal of Pharmaceutics 12/2013; · 3.99 Impact Factor
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    ABSTRACT: Abstract To develop naphthyridine derivatives as anticancer candidates, pharmacokinetic (PK) evaluations of 10 novel derivatives of 1,4-dihydro-4-oxo-1-proparagyl-1,8-naphthyridine-3-carboxamide, with potent anticancer activity were done using in vitro ADME (absorption, distribution, metabolism, excretion) and pharmacokinetic--pharmcodynamic (PK/PD) assays. Only derivatives 5, 6, 9 and 10 showed better metabolic stability, solubility, permeability, partition coefficient and cytochrome P450 (CYP) inhibition values. PK of derivatives 5, 6, 9 and 10 in rat showed comparable PK profile for derivative 5 (C0 = 6.98 µg/mL) and 6 (C0 = 6.61 µg/mL) with no detectable plasma levels for derivatives 9 and 10 at 5.0 mg/kg i.v. dose. PK/PD assay of derivatives 5 and 6 in tumor-bearing mice (TBM) showed comparable PK but tumor plasma index (TPI) of derivative 6 (4.02) was better than derivative 5 (2.50), suggesting better tumor uptake of derivative 6. Derivative 6, as lead compound, showed highest tumor growth inhibition (TGI) value of 33.6% in human ovary cancer xenograft model.
    Journal of Enzyme Inhibition and Medicinal Chemistry 10/2013; · 1.50 Impact Factor
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    ABSTRACT: The purpose of this work is intended to investigate the potential of self-nanoemulsifying (SNE) drug delivery system for enhanced oral bioavailability of etoposide by P-glycoprotein (P-gp) modulation. The components of SNE formulation were optimized by their solubilization and emulsification efficiency. The ternary phase diagrams provided nanoemulsion existence ranges and the corresponding formulations were developed and evaluated via thermodynamic and dispersibility tests. The successful formulations were characterized for various parameters including time required for self-emulsification, percentage transmittance, droplet size, surface morphology, zeta potential and in vitro release. The etoposide loaded SNE9 formulation showed 2.6- and 11-fold higher permeability coefficient in apical to basolateral direction across Caco-2 monolayers as compared to the Etosid and plain drug solution, respectively. The etoposide loaded SNE9 formulation showed a higher cytotoxicity at the highest tested concentration compared to the blank SNE9 formulation and the free etoposide. Furthermore, an in vivo pharmacokinetic study of etoposide in SNE9 formulation showed 3.2- and 7.9-fold increase in relative oral bioavailability compared with that of etoposide in Etosid and drug suspension, respectively. Thus, the developed SNE drug delivery system could be a valuable tool for the effective oral delivery of etoposide.
    Journal of Biomedical Nanotechnology 07/2013; 9(7):1216-29. · 7.58 Impact Factor
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    ABSTRACT: We have previously synthesized a series of 1,8-naphthyridine-3-carboxamide derivatives to identify potential anti-cancer/anti-inflammatory compounds. Three derivatives, 7-chloro-N-(3-(cyclopentylamino)-3-oxo-1-phenylpropyl)-6-fluoro-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-22), 7-chloro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-31) and 7-chloro-6-fluoro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-34) demonstrated high cytotoxicity against a number of cancer cell lines and inhibited secretion of IL-1-β and IL-6. In the present study, C-22, C-31 and C-34 were assessed for modulation of pro-inflammatory cytokines, TNF-α and IL-8, chemokine RANTES and NO produced by lipopolysaccharide (LPS)-treated mouse Dendritic cells (DCs). Among the 3 compounds, C-34 showed the most potent inhibition of inflammatory markers in DC model at 0.2 and 2μM. C-34 also significantly downregulated the secretion of TNF-α, IL-1-β and IL-6 by murine splenocytes and THP-1 cells against LPS induced levels. In vitro effects of C-34 on bone marrow toxicity were assessed in CFU-GM assay. Human CFU-GM population was comparatively more sensitive to C-34 (0.1-10μM) than murine CFU-GM. IC(50) values for murine and human CFU-GM were not attained. C-34 was further examined for in vivo suppression of LPS induced cytokines in a mice model. At doses ranging from 1.25 to 5mg/kg, C-34 led to significant inhibition of TNF-α, IL-1-β, IL-6 and MIP-1-α. At the highest dose of 5mg/kg, C-34 also protected LPS-treated mice against endotoxin-induced lethality. In conclusion, C-34 demonstrates anti-inflammatory activity in vitro and in vivo in addition to cytotoxic properties. This finding suggests its potential for further development as a synthetic naphthyridine derivative with dual anti-cancer and anti-inflammatory (cytokine inhibition) properties.
    International immunopharmacology 01/2013; · 2.21 Impact Factor
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    ABSTRACT: The present investigation was aimed to establish a validated stability-indicating liquid chromatographic method for the estimation of etoposide (ETP) in bulk drug and self-nano emulsifying formulation. ETP was successfully separated from the degradation products formed under stress conditions on LiChrospher 100 C18 reverse-phase column (a 250 mm × 4.6 mm i.d., 5-μm particle size) using 55:45 (v/v) acetonitrile-phosphate buffer saline (pH 4.5) as the mobile phase, at a flow rate of 1.0 mL min(-1) and detection at 283 nm. The response was a linear function of analyte concentration (R(2) > 0.9997) over the concentration range of 0.05-50 μg mL(-1). The method was validated for precision, accuracy, robustness, sensitivity and specificity. The % recovery of ETP at three different levels (50%, 100% and 150%) ranged between 93.84% and 100.06% in optimized self-nano emulsifying formulation, Etosid® soft-gelatin capsule and Fytosid® injection. First-order degradation kinetics of ETP were observed under acidic and alkaline conditions. The method was also applied for the stability assessment of self-nano emulsifying formulation under accelerated conditions, the formulation was found to be stable at all storage conditions with the shelf-life of 2.37 years at 25 °C. The method holds promise for routine quality control of ETP in bulk, pharmaceutical formulations as well as in stability-indicating studies.
    Saudi Pharmaceutical Journal 01/2013; 21(1):103-11. · 0.95 Impact Factor
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    ABSTRACT: Novel betulinic acid derivative 5'-chloro-2, 3-didehydroindolo [2', 3': 2, 3] betulinic acid (DRF-4012) is a new effective lupane type triterpenes with greater anticancer activity and efficacy than betulinic acid and currently under advanced preclinical investigation phase. In this study, a sensitive and rapid liquid chromatography-electrospray mass spectrometric (LC/MS) method has been developed for the determination of DRF-4012 in tumour-bearing mice plasma, urine, feces and tissues (liver, brain, lungs, heart, spleen, stomach, thigh muscle, kidneys, urinary bladder, small intestine and tumour). Biodistribution and excretion studies were performed for DRF-4012 nanoparticle (30 mg/kg body weight) after intravenous (i.v.) injection in tumour-bearing mice. DRF-4012 rapidly distributed throughout the body. After 0.5 h, tumour showed the second highest concentration, which was nearly half of the liver. After 4 and 24 h, the highest concentration of DRF-4012 was found in tumour indicating its retention in tumour site for a longer time. Excretion studies revealed that very low amount of unchanged DRF-4012 was observed in urine and primarily excreted through fecal route. This study may be useful to explain the manner in which DRF-4012 can inhibit tumour growth without apparent toxicity and preclinical/clinical evaluation of this potential antitumour agent.
    Xenobiotica 12/2012; · 1.98 Impact Factor
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    ABSTRACT: Development of an effective formulation involves careful optimization of a number of excipient and process variables. Sometimes the number of variables is so large that even the most efficient optimization designs require a very large number of trials which put stress on costs as well as time. A creative combination of a number of design methods leads to a smaller number of trials. This study was aimed at the development of nanostructured lipid carriers (NLCs) by using a combination of different optimization methods. A total of 11 variables were first screened using the Plackett-Burman design for their effects on formulation characteristics like size and entrapment efficiency. Four out of 11 variables were found to have insignificant effects on the formulation parameters and hence were screened out. Out of the remaining seven variables, four (concentration of tween-80, lecithin, sodium taurocholate, and total lipid) were found to have significant effects on the size of the particles while the other three (phase ratio, drug to lipid ratio, and sonication time) had a higher influence on the entrapment efficiency. The first four variables were optimized for their effect on size using the Taguchi L9 orthogonal array. The optimized values of the surfactants and lipids were kept constant for the next stage, where the sonication time, phase ratio, and drug:lipid ratio were varied using the Box-Behnken design response surface method to optimize the entrapment efficiency. Finally, by performing only 38 trials, we have optimized 11 variables for the development of NLCs with a size of 143.52 ± 1.2 nm, zeta potential of -32.6 ± 0.54 mV, and 98.22 ± 2.06% entrapment efficiency.
    Nanotechnology 12/2012; 24(1):015104. · 3.84 Impact Factor
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    ABSTRACT: CD44 or hyaluronan receptor is a transmembrane receptor associated with aggressive tumour growth, proliferation, and metastasis. In normal physiology, this receptor has a crucial role in cell adhesion, inflammation, and repair processes. However, many tumour cells over-express this receptor and abuse it to become progressive and perpetual units. The article comments from common functioning of the CD44 receptor, to its diabolic multi-dimensional effects in promotion of malignant cells. It also illuminates the relations of CD44 endorsed processes with other biomolecular events in cancer progression. In an end, the review focuses comprehensively at ongoing researches to exploit the CD44 over-expression as a probable target in treatment, management, and diagnosis of malignancy.
    Journal of Drug Targeting 08/2012; 20(7):561-73. · 2.77 Impact Factor
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    ABSTRACT: INTRODUCTION: An increasing research interest has been directed toward nanoparticle-based drug delivery systems for their advantages. The appropriate amalgamation of pH sensitivity and tumor targeting is a promising strategy to fabricate drug delivery systems with high efficiency, high selectivity and low toxicity. MATERIALS AND METHODS: A novel pH sensitive Cremophor-free paclitaxel formulation, Nanoxel(TM), was developed in which the drug is delivered as nanomicelles using a polymeric carrier that specifically targets tumors. The efficiency and mechanism of intracellular paclitaxel delivery by Nanoxel(TM) was compared with two other commercially available paclitaxel formulations: Abraxane(TM) and Intaxel(TM), using different cell lines representing target cancers [breast, ovary and non-small cell lung carcinoma (NSCLC)] by transmission electron microscopy and quantitative intracellular paclitaxel measurements by high performance liquid chromatography. RESULTS: The data obtained from the present study revealed that the uptake of nanoparticle-based formulations Nanoxel(TM) and Abraxane(TM) is mediated by the process of endocytosis and the uptake of paclitaxel was remarkably superior to Intaxel(TM) in all cell lines tested. Moreover, the intracellular uptake of paclitaxel in Nanoxel(TM)- and Abraxane(TM)-treated groups was comparable. Hence, the nanoparticle-based formulations of paclitaxel (Nanoxel(TM) and Abraxane(TM)) are endowed with higher efficiency to deliver the drug to target cells as compared to the conventional Cremophor-based formulation. CONCLUSION: Nanoxel(TM) appears to be of great promise in tumor targeting and may provide an advantage for paclitaxel delivery into cancer cells.
    Clinical and Translational Oncology 07/2012; · 1.28 Impact Factor
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    ABSTRACT: INTRODUCTION: The ATP-binding cassette superfamily contains membrane transporter proteins that transport a wide range of diverse compounds across cellular membranes. The P-glycoprotein (P-gp) is an important member of this family and a multi-specific drug efflux transporter that plays a significant role in governing the bioavailability of many clinically active drugs. The inhibition of this efflux transporter by various P-gp inhibitors forms a distinctive approach in improving bioavailability and conquering drug resistance. Most P-gp inhibitors exhibit limitations associated with their safety and unwanted pharmacokinetic interactions, thereby restraining their clinical applicability. AREAS COVERED: This review explores the investigations on the feasibility and applicability of various classes of P-gp inhibitors as described in recent patents for enhanced drug delivery. EXPERT OPINION: Several candidates presently under development look promising as P-gp inhibitors, e.g., tariquidar and elacridar. Pharmaceutical excipients currently constitute the most promising class of P-gp inhibitors and are considered safe and pharmaceutically acceptable for use in formulations. In addition, lipid-based excipients and thiolated polymers play an active role in affecting P-gp-mediated transport not only by altering the membrane fluidity or ATPase activity but by down regulating P-gp expression. An additional overture such as the prodrug derivatization of P-gp substrates is a feasible approach to bypass P-gp-mediated efflux.
    Expert Opinion on Therapeutic Patents 04/2011; 21(4):561-76. · 3.53 Impact Factor
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    ABSTRACT: A simple, sensitive, precise, and accurate stability-indicating high performance thin-layer chromatographic method for analysis of irinotecan both as bulk drug and in marketed injectables has been developed and validated as per ICH guidelines. Chromatographic separation was achieved on LiChrospher aluminum plates precoated with silica gel 60F254 as stationary phase. The solvent system consisted of acetone–ethyl acetate–acetic acid 8.5:1.5:0.1 (v/v/v) and this system was found to give compact spots for irinotecan at RF value of 0.31 ± 0.02. Densitometric analysis was performed in the absorbance at 366 nm. The linear regression analysis for the calibration plots showed good linear relationship with r2 = 0.9973 ± 0.0013 in the concentration range of 50–500 ng/spot. The method was validated for precision, accuracy, recovery, and specificity. The % recovery (94.63–101.40%) and precision (≤4.30) were found to be satisfactory. Irinotecan was subjected to acid and alkali hydrolysis, oxidation, thermal, and ultraviolet radiation treatments. All the peaks of degradation products were well resolved from the standard drug with significantly different retention factor (RF) values. Developed method effectively separated out the drug from its degradation products and hence can be used as stability-indicating method as well as in routine analysis of irinotecan.
    Journal of Liquid Chromatography & Related Technologies - J LIQ CHROMATOGR RELAT TECHNO. 01/2011; 34(14):1459-1472.
  • European Journal of Cancer - EUR J CANCER. 01/2011; 47.
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    ABSTRACT: Considerable research efforts have been directed towards understanding the enigma of P-glycoprotein (P-gp) in drug development and delivery. P-gp is a multi-specific drug efflux transporter that plays a significant role in governing the bioavailability of various anti-cancer drugs. Modulation of this efflux transporter by various traditional 'chemosensitisers' forms a distinctive approach in improving pharmacokinetics and conquering drug resistance. However, such inhibitors show limitations associated with their safety and unwanted pharmacokinetic drug interaction restraining their clinical applicability. To address these concerns, several research groups have used pharmaceutical excipients (functional excipients or additives) to inhibit P-gp and enhance drug permeability. This article focuses on such excipients, various co-development strategies for the formulation of cytotoxic drugs with this multi-drug resistance (MDR) reversing additives.
    Drug discovery today 08/2009; 14(21-22):1067-74. · 6.63 Impact Factor
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    ABSTRACT: Two potent cis-restricted CA-4 analogues 11 and 42 belonging to 2,3-diaryl-5-hydroxycyclopent-2-en-1-one class were evaluated for anticancer and anti angiogenic activity. The compound 42 displayed potent cytotoxic activity (IC(50) < 1 muM) against a panel of human cancer cell lines viz PTC, MDA.MB.453, PA1, SKOV3, DU145 and Miapaca2, whereas compound 11 displayed cytotoxicity activity (IC(50) < 1 microM) only in Miapaca2. Both the compounds inhibit growth factor stimulated endothelial cell proliferation, migration and capillary tube formation. In all the above parameter compound 42 was superior to 11. Based on the above results compound 42 was assessed for inhibition of vasculature in vivo and showed significant inhibition at 25 mg/kg dose. Further it was evaluated for in vivo anti tumor activity in athymic mice bearing DU145 and SKVO3 tumor xenograft and showed regression in tumor volume (T/C) of 23.8% (CA-4), 50.1% (compound 42) and 23.5% (CA-4), 56% (compound 42) respectively at a dose of 20 mg/kg (i.v.) daily for 14 days.
    Investigational New Drugs 05/2009; 28(4):363-80. · 3.50 Impact Factor
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    ABSTRACT: A number of 1,8-naphthyridine derivatives (22-62) have been synthesized and screened for their in vitro cytotoxicity against eight tumors and two non-tumor cell lines. Halogen substituted 1,8-naphthyridine-3-caboxamide derivatives showed potent activity with compound 47 having IC(50) of 0.41 and 0.77 microM on MIAPaCa and K-562 cancer cell lines, respectively while, compound 36 had IC(50) of 1.19 microM on PA-1 cancer cell line. However, one of the unsubstituted 1,8-naphthyridine-C-3'-heteroaryl derivative 29 showed potent cytotoxicity with IC(50) of 0.41 and 1.4 microM on PA-1 and SW620 cancer cell lines, respectively. These compounds were also evaluated for anti-inflammatory activity as suggested by downregulation of proinflammaotory cytokines.
    Journal of Enzyme Inhibition and Medicinal Chemistry 05/2009; 24(5):1169-78. · 1.50 Impact Factor
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    ABSTRACT: Cancer treatment by drugs is seriously limited by P-glycoprotein (P-gp) associated multi-drug resistance (MDR) in various tumor cells. It is now widely recognized that P-gp influences drug transport across various biological membranes. P-gp transporter is widely present in various body tissues affecting absorption, distribution, metabolism and excretion of drugs. Clinical significance of above mentioned carrier is appreciated from the fact that more than fifty percent of existing anti-cancer drugs undergo inhibitable and saturable P-gp mediated efflux. Consequently, there is an increasing trend to optimize pharmacokinetics, enhance antitumour activity and reduce systemic toxicity of existing anticancer drugs by inhibiting P-gp mediated transport. Although a wide variety of P-gp inhibitors have been discovered, research efforts are underway to identify the most appropriate one. Flavanoids belong to the third generation, nonpharmaceutical category of P-gp inhibitors. Among different classes of flavonoids, flavonols are the most explored P-gp inhibitors by several research groups. This could possibly be because of the fact that the effects produced by these are found to be comparable to those of well-known potent P-gp inhibitors verapamil and cyclosporine. Identification of effective P-gp modulator among herbal compounds have an added advantage of being safe, thereby making them ideal candidates for bioavailability enhancement, tissue-penetration (e.g. blood brain barrier), decreasing biliary excretion and multidrug resistance modulating agents. The dual effects, i.e. P-gp modulation and antitumor activity, of these herbal derivatives may synergistically act in cancer chemotherapy. This paper presents an overview of the investigations on the feasibility and application of flavonols as P-gp modulators for improved efficacy of anti-cancer drugs. The review also focuses on flavonol-drug interactions as well as the reversal activity of flavonols useful against MDR.
    Current Cancer Therapy Reviews 04/2009; 5(2):89-99.
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    ABSTRACT: A number of 1-propargyl-1,8-naphthyridine-3-carboxamide derivatives (15-35) have been synthesized and screened for their in vitro cytotoxicity and anti-inflammatory activity. Compounds 22, 31 and 34 have shown high cytotoxicity against a number of cancer cell lines, while compound 24 showed significant anti-inflammatory activity.
    European journal of medicinal chemistry 04/2009; 44(8):3356-62. · 3.27 Impact Factor
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    ABSTRACT: Chemotherapy forms the mainstay of cancer treatment particularly for patients who do not respond to local excision or radiation treatment. However, cancer treatment by drugs is seriously limited by P-glycoprotein (P-gp) associated multi-drug resistance (MDR) in various tumor cells. On the other hand, it is now widely recognized that P-gp also influences drug transport across various biological membranes. P-gp transporter is widely present in the luminal surface of enterocytes, biliary canalicular surface of hepatocytes, apical surface of proximal tubular cells of kidney, endothelial cells of blood brain barrier, etc. thus affecting absorption, distribution, metabolism and excretion of xenobiotics. Clinical significance of above mentioned carrier is appreciated from the fact that more than fifty percent of existing anti-cancer drugs undergo inhibitable and saturable P-gp mediated efflux. Consequently, there is an increasing trend to optimize pharmacokinetics, enhance antitumour activity and reduce systemic toxicity of existing anti-cancer drugs by inhibiting P-gp mediated transport. Although a wide variety of P-gp inhibitors have been discovered, research efforts are underway to identify the most appropriate one. Flavonoids (polyphenolic herbal constituents) form the third generation, non-pharmaceutical category of P-gp inhibitors. The effects produced by some of these components are found to be comparable to those of well-known P-gp inhibitors verapamil and cyclosporine. Identification of effective P-gp modulator among herbal compounds have an added advantage of being safe, thereby making them ideal candidates for bioavailability enhancement, tissue-penetration (e.g. blood brain barrier (BBB)), decreasing biliary excretion and multi-drug resistance modulating agents. The dual effects, i.e. P-gp modulation and antitumor activity, of these herbal derivatives may synergistically act in cancer chemotherapy. This paper presents an overview of the investigations on the feasibility and application of flavonoids as P-gp modulators for improved efficacy of anti-cancer drugs like taxanes, anthracyclines, epipodophyllotoxins, camptothecins and vinca alkaloids. The review also focuses on flavonoid-drug interactions as well as the reversal activity of flavonoids useful against MDR. In addition, the experimental models which could be used for investigation on P-gp mediated efflux are also discussed.
    Journal of Pharmacy and Pharmaceutical Sciences 02/2009; 12(1):46-78. · 2.20 Impact Factor
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    ABSTRACT: The objective of present investigation was to study the effect of verapamil on the pharmacokinetics of irinotecan in order to evaluate the role of P-glycoprotein (P-gp) in irinotecan disposition. An in vitro study using Caco-2 intestinal cell monolayer was first carried out to determine the effect of verapamil on the function of intestinal P-gp. Verapamil (25mg/kg) was administered orally 2h before irinotecan oral (80 mg/kg) or intravenous (20mg/kg) dosing in female Wistar rats. Plasma and biliary samples were collected at specified time points from control and treated animals to determine irinotecan and its metabolite, SN-38 concentrations. Bi-directional transport and inhibition studies in Caco-2 cells indicated irinotecan to be a P-gp substrate and the function of intestinal P-gp was significantly inhibited in presence of verapamil. After oral irinotecan dosing, the mean area under the plasma concentration-time curve (AUC) was found to be 14.03+/-2.18 microgh/ml which was increased significantly, i.e. 61.71+/-15.0 microgh/ml when verapamil was co-administered (P<0.05). Similarly, the mean maximum plasma concentration of irinotecan increased from 2.93+/-0.37 microg/ml (without verapamil) to 10.75+/-1.0 microg/ml (with verapamil) (P<0.05). There was approximately 4-5-folds increase in apparent bioavailability. On the other hand, the intravenous irinotecan administration with verapamil resulted in small but statistically significant effect on AUC (10.76+/-2.0 to 23.3+/-3.8 microgh/ml; P<0.05) and systemic clearance (1206.4+/-159.7 to 713.5+/-78.2 ml/(hkg)). In addition, SN-38 showed significant change in oral pharmacokinetic parameters and minor changes in intravenous pharmacokinetic profile. Biliary excretion curves of both irinotecan and SN-38 were lowered by verapamil. The mean percent of irinotecan excreted into bile over 5h following intravenous and oral administration was found to be 8% and 1%, respectively, which was further reduced to half when treated with verapamil. These results are quite stimulating for further development of a clinically useful oral formulation of irinotecan based on P-gp inhibition.
    European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 01/2009; 36(4-5):580-90. · 2.61 Impact Factor

Publication Stats

311 Citations
105.27 Total Impact Points

Institutions

  • 2007–2013
    • Dabur Research Foundation
      Ghazibad, Uttar Pradesh, India
    • Jamia Hamdard University
      • Department of Pharmaceutics
      New Delhi, NCT, India
    • National Chemical Laboratory
      Poona, Mahārāshtra, India