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Vibrational Spectroscopic Study of Fluticasone Propionate

Research Abstract
Fluticasone propionate is a synthetic glucocorticoid with potent anti-inflammatory activity that has been used effectively in the treatment of chronic asthma. The present work reports a vibrational spectroscopic study of fluticasone propionate and gives proposed molecular assignments on the basis of ab initio calculations using BLYP density functional theory with a 6-31G* basis set and vibrational frequencies predicted within the quasi-harmonic approximation. Several spectral features and band intensities are explained. This study generated a library of information that can be employed to aid the process monitoring of fluticasone propionate.
Research Authors
H. R. H. Ali, H. G. M. Edwards, J. Kendrick, I. J. Scowen
Research Journal
Spectrochimica Acta Part A, doi: 10.1016/j.saa.2008.08.004
Research Member
Research Rank
1
Research Vol
Vol.  72
Research Year
2009

Vibrational Spectroscopic Characterisation of Salmeterol Xinafoate Polymorphs and a Preliminary Investigation of their Transformation Using Simultaneous In situ Portable Raman Spectroscopy and Differential Scanning Calorimetry

Research Abstract
Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting -adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry. The solid-state transition of salmeterol xinafoate polymorphs was studied using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry isothermally between transitions. This method assisted in the unambiguous characterisation of the two polymorphic forms by providing a simultaneous probe of both the thermal and vibrational data. The study demonstrates the value of a rapid in situ analysis of a drug polymorph which can be of potential value for at-line in-process control.
Research Authors
Hassan Refat H. Ali, Howell G. M. Edwards, Michael D. Hargreaves, Tasnim Munshi, Ian J. Scowen, Richard J. Telford
Research Journal
Analytica Chimica Acta, doi: 10.1016/j.aca.2008.05.009
Research Member
Research Rank
1
Research Vol
Vol.  620
Research Year
2008

Vibrational Spectroscopic Study of Budesonide

Research Abstract
The Raman spectrum of budesonide is reported for the first time, and molecular assignments are proposed on the basis of ab initio BLYP DFT calculations with a 6-31 G* basis set and vibrational wavenumbers predicted on a quasi-harmonic approximation. Comparison with previously published infrared data has explained several spectral features, and the relative band intensities in the C=O and C=C stretching regions are interpreted. The results from this study provide data that can be used for the preparative process monitoring of budesonide, an important steroidal pharmaceutical in various dosage forms, and its interaction with excipients and other components.
Research Authors
H. R. H. Ali, H. G. M. Edwards, J. Kendrick, T. Munshi, I. J. Scowen
Research Journal
J. Raman Spectrosc., DOI: 10.1002/jrs.1744
Research Member
Research Rank
1
Research Vol
Vol.  38
Research Year
2007

Raman Spectroscopy of Natron: Shedding Light on Ancient Egyptian Mummification

Research Abstract
The mummification ritual in ancient Egypt involved the evisceration of the corpse and its desiccation using natron, a naturally occurring evaporitic mineral deposit from the Wadi Natrun, Egypt. The deposit typically contains sodium carbonate, sodium bicarbonate and impurities of chloride and sulfate as its major elemental components. It is believed that the function of the natron was to rapidly remove the water from the cadaver to prevent microbial attack associated with subsequent biological tissue degradation and putrefaction. Several specimens of natron that were recently collected from the Wadi Natrun contained coloured zones interspersed with the mineral matrix that are superficially reminiscent of extremophilic cyanobacterial colonisation found elsewhere in hot and cold deserts. Raman spectroscopy of these specimens using visible and near-infrared laser excitation has revealed not only the mineral composition of the natron, but also evidence for the presence of cyanobacterial colonies in several coloured zones observed in the mineral matrix. Key Raman biosignatures of carotenoids, scytonemin and chlorophyll have been identified.
Research Authors
Howell G. M. Edwards, Katherine J. Currie, Hassan R. H. Ali, Susana E. Jorge Villar, A. Rosalie David, John Denton
Research Journal
Anal. Bioanal. Chem., DOI: 10.1007/s00216-007-1249-4
Research Member
Research Rank
1
Research Vol
Vol.  388
Research Year
2007

Trimethyl-4-Oxo-4,5,6,7-Tetrahydroindazole-1-Acetic Acid: A New Lead Compound with Selective COX-2 Inhibitory Activity

Research Abstract
A novel series of 3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydroindazole-1-acetic acid derivatives was designed and synthesized by a new one-step pathway. Structure elucidation of the synthesized compounds was confirmed by various spectral and elemental analyses. The prepared compounds were evaluated for their ability to inhibit cyclooxygenase-2 (COX-2) and cyclooxygenase-1 (COX-1) enzymes in-vitro. Among the synthesized compounds, the 2-(3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydroindazol-1-yl)acetic acid 4 emerged as the most potent COX-2 inhibitor (IC50 value: 150 nM) with the highest selectivity index (COX-1 / COX-2 inhibition ratio: 570.6). Docking studies of compound 4 in the active site of COX-2 recognized its potential binding mode to the enzyme. Based on the preliminary results, compound 4 was considered as a lead compound for further optimization.
Research Authors
Hamdy M. Abdel-Rahman, Keriman Ozadali
Research Journal
Arch. Pharm. Chem. Life Sci., DOI: 10.1002/ardp.201200193
Research Rank
1
Research Vol
Vol. 345
Research Year
2012

Dendrimers and Miktoarm Polymers Based Multivalent Nanocarriers for Efficient and Targeted Drug Delivery

Research Abstract
The delivery of biologically active agents to the desired site in the body and intracellular organelles is still a big challenge despite efforts made for more than five decades. With the elaboration of synthetic methodologies to branched and hyperbranched macromolecules such as miktoarm stars and dendrimers, the focus has shifted to nanocarriers able to release and direct drug molecules to a desired location in a controlled manner. We present here recent developments in the field of targeted drug delivery with a focus on two specific macromolecular nanocarriers, dendrimers and miktoarm stars, and provide examples of these nanocarriers tested in different biological systems. A particular attraction of miktoarm stars is their versatility in achieving superior drug loading within their self-assembled structures. Advantages of dendrimers over linear polymers are that the former provide a platform for development of multivalent and multifunctional nanoconjugates, in addition to their ability to accommodate a large number of molecules inside, or at their surfaces.
Research Authors
Ghareb M. Soliman, Anjali Sharma, Dusica Maysinger, Ashok Kakkar
Research Department
Research Journal
Chemical Communications, doi:10.1039/C1CC11981H
Research Rank
1
Research Vol
Vol. 47
Research Year
2011

Short Ligands Affect Modes of QD Uptake and Elimination in Human Cells

Research Abstract
In order to better understand nanoparticle uptake and elimination mechanisms, we designed a controlled set of small, highly fluorescent quantum dots (QDs) with nearly identical hydrodynamic size (8-10 nm) but with varied short ligand surface functionalization. The properties of functionalized QDs and their modes of uptake and elimination were investigated systematically by asymmetrical flow field-flow fractionation (AF4), confocal fluorescence microscopy, flow cytometry (FACS), and flame atomic absorption (FAA). Using specific inhibitors of cellular uptake and elimination machinery in human embryonic kidney cells (Hek 293) and human hepatocellular carcinoma cells (Hep G2), we showed that QDs of the same size but with different surface properties were predominantly taken up through lipid raft-mediated endocytosis, however, to significantly different extents. The latter observation infers the contribution of additional modes of QD internalization, which include X-AG cysteine transporter for cysteine-functionalized QDs (QD-CYS). We also investigated putative modes of QD elimination and established the contribution of P-glycoprotein (P-gp) transporter in QD efflux. Results from these studies show a strong dependence between the properties of QD-associated small ligands and modes of uptake/elimination in human cells.
Research Authors
Noura A. Al-Hajaj, Alexandre Moquin, Kevin D. Neibert, Ghareb M. Soliman, Francoise M. Winnik, Dusica Maysinger
Research Department
Research Journal
ACS Nano
Research Rank
1
Research Vol
Vol. 5, No. 6
Research Year
2011

Design and Evaluation of Multifunctional Nanocarriers for Selective Delivery of Coenzyme Q10 to Mitochondria

Research Abstract
Impairments of mitochondrial functions have been associated with failure of cellular functions in different tissues, leading to various pathologies. We report here a mitochondria-targeted nanodelivery system for coenzyme Q10 (CoQ10) that can reach mitochondria and deliver CoQ10 in adequate quantities. Multifunctional nanocarriers based on ABC miktoarm polymers (A = poly(ethylene glycol (PEG), B = polycaprolactone (PCL), and C = triphenylphosphonium bromide (TPPBr)) were synthesized using a combination of click chemistry with ring-opening polymerization, self-assembled into nanosized micelles, and were employed for CoQ10 loading. Drug loading capacity (60 wt%), micelle size (25-60 nm), and stability were determined using a variety of techniques. The micelles had a small critical association concentration and were colloidally stable in solution for more than 3 months. The extraordinarily high CoQ10 loading capacity in the micelles is attributed to good compatibility between CoQ10 and PCL, as indicated by the low Flory−Huggins interaction parameter. Confocal microscopy studies of the fluorescently labeled polymer analog together with the mitochondria-specific vital dye label indicated that the carrier did indeed reach mitochondria. The high CoQ10 loading efficiency allowed testing of micelles within a broad concentration range and provided evidence for CoQ10 effectiveness in two different experimental paradigms: oxidative stress and inflammation. Combined results from chemical, analytical, and biological experiments suggest that the new miktoarm-based carrier provides a suitable means of CoQ10 delivery to mitochondria without loss of drug effectiveness. The versatility of the click chemistry used to prepare this new mitochondria-targeting nanocarrier offers a widely applicable, simple, and easily reproducible procedure to deliver drugs to mitochondria or other intracellular organelles.
Research Authors
Anjali Sharma, Ghareb M. Soliman, Noura Al-Hajaj, Rishi Sharma, Dusica Maysinger, Ashok Kakkar
Research Department
Research Journal
Biomacromolecules, dx.doi.org/10.1021/bm201538j
Research Rank
1
Research Vol
Vol. 13
Research Year
2012

Modulation of Inflammatory Signaling and Cytokine Release from Microglia by Celastrol Incorporated into Dendrimer Nanocarriers

Research Abstract
Aim: This study investigates the capacity of a potent anti-inflammatory nanomedicine, celastrol, incorporated into poly(amidoamine) dendrimers, to inhibit endotoxin-mediated signaling in microglia. Materials & methods: Celastrol was incorporated into amino (Cel/G4-NH2) and hydroxyl (Cel/G4-OH) terminus poly(amidoamine) (G4) dendrimers. Cell viability, release of nitric oxide, IL-6, TNF- and activation of MAPK (e.g., p38 and JNK) and NF-B were assessed in endotoxin (i.e., lipopolysaccharide) stimulated microglial cells. Results: G4-OH and G4-NH2 increased celastrol aqueous solubility by seven- and 12-fold, respectively. G4-OH and Cel/G4-OH suppressed lipopolysaccharide-mediated release of proinflammatory mediators, such as nitric oxide and IL-6, but not TNF-, without reducing microglial cell viability, while Cel/G4-NH2 potentiated cytotoxicity and cytokine release. Blockade of proinflammatory signaling was accompanied by attenuation of p38 MAPK activation. Conclusion: This study supports the potential use of poly(amidoamine) dendrimers for effective anti-inflammatory therapy in the chronically inflamed CNS.
Research Authors
Sebastien Boridy, Ghareb M. Soliman, Dusica Maysinger
Research Department
Research Journal
Nanomedicine
Research Rank
1
Research Vol
Vol. 7, No. 8
Research Year
2012

Non-Invasive In situ Identification and Band Assignments of Diazepam, Flunitrazepam and Methadone Hydrochloride with FT-Near-Infrared Spectroscopy

Research Abstract
Near-infrared spectroscopy (NIR) has evolved into an important rapid, direct and non-invasive technique in drugs analysis. In this study, the suitability of NIR spectroscopy to identify two benzodiazepine derivatives, diazepam and flunitrazepam, and a synthetic opiate, methadone hydrochloride, inside USP vials and probe the solid-state form of diazepam presents in tablets has been explored. The results show the potential of NIR spectroscopy for rapid, in situ and non-destructive identification of drugs.
Research Authors
Hassan Refat H. Ali
Research Journal
Forensic Science International, doi:10.1016/j.forsciint.2010.06.029
Research Member
Research Rank
1
Research Vol
Vol. 206
Research Year
2011
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