Fatma Bassyouni

Solid Phase Microextraction and Related Techniques for Drugs in Biological Samples

In drug discovery and development, the quantification of drugs in biological samples is an important task for the determination of the physiological performance of the investigated drugs. After sampling, the next step in the analytical process is sample preparation. Because of the low concentration levels of drug in plasma and the variety of the metabolites, the selected extraction technique should be virtually exhaustive. Recent developments of sample handling techniques are directed, from one side, toward automatization and online coupling of sample preparation units. The primary objective of this review is to present the recent developments in microextraction sample preparation methods for analysis of drugs in biological fluids. Microextraction techniques allow for less consumption of solvent, reagents, and packing materials, and small sample volumes can be used. In this review the use of solid phase microextraction (SPME), microextraction in packed sorbent (MEPS), and stir-bar sorbtive extraction (SBSE) in drug analysis will be discussed. In addition, the use of new sorbents such as monoliths and molecularly imprinted polymers will be presented.

On-Line Determination of Cyclophosphamide in Blood Samples Utilizing Microextraction by Packed Sorbent and Liquid Chromatography Tandem Mass Spectrometry (MEPS-LC-MS/MS)

Microextraction by packed sorbent (MEPS) was used to handle whole mice blood samples. MEPS was used as an online rapid sample-preparation method, followed by liquid chromatography with tandem mass spectrometry (LC- MS/MS). Cyclophosphamide in mice blood was used as a model compound. The new method reduced the handling time and the cost and could handle small volumes of whole blood samples (20 μL). The lower limit of quantification (LLOQ) was 0.1μg/mL. The accuracy of the quality-control (QC) samples ranged from 107 to 110 %. The within-day variation was within the range 2.0-7.0% (C.V.%) while the between-day variation was between 4.0 and 6.0% (C.V.%). The calibra- tion curve in whole blood was constructed within the concentration range 0.1-100 μg/mL. The coefficients of determina- tion (R 2 ) were > 0.99 (n = 3). The present method is rapid, reliable and accurate and may be used for therapeutic drug monitoring of cyclophosphamide in whole blood. The method was applied for preclinical study of cyclophosphamide in mice.

Synthesis and biological evaluation of some new triazolo[1,5-a]quinoline derivatives as anticancer and antimicrobial agents

In the present study, versatile multifunctional unreported triazolo[1,5-a]quinoline derivatives were prepared. Compounds 1–19 were synthesized by adopting appropriate synthetic routes and were pharmacologically evaluated for their in vitro anticancer activity against human cancer cell lines: hepatocellular liver carcinoma (HEPG2) and Caucasian breast adenocarcinoma (MCF-7), in addition to their antibacterial and antifungal activities. Compound 4 demonstrated strong inhibitory effects against breast cancer (MCF-7), whereas compounds 8 and 19 exhibited moderate activity against breast carcinoma cell line MCF-7. Compounds 16 and 19 gave moderate activity against liver carcinoma cell line HEPG2. The antimicrobial activity of the prepared compounds was tested against bacteria and fungi. Among them, the results of antimicrobial activity indicated that compounds 4, 9, 11, 13, 15, 17, 18 and 19 were the most active compounds. Compound 4 exhibited strong activity against Fusarium sp., whereas compounds 9, 11, 15, 17, 18 and 19 showed high activity against Escherichia coli. More specifically, compound 17 displayed a high inhibitory effect against Bacillus cereus, Escherichia coli and Rhizoctonia sp.

Advances and new technologies applied in controlled drug delivery system

A drug delivery system is defined as a formulation or a device that enables the introduction of a therapeutic substance into the body and improves its efficacy and safety by controlling the rate, time, and place of release of drugs in the body. This process includes the administration of the therapeutic product, the release of the active ingredients by the product, and the subsequent transport of the active ingredients across the biological membranes to the site of action. Drug delivery systems aim to improve patient compliance and convenience, such as, for example, fast-dissolving tablets. One of the most important goals of pharmaceutical science is localizing the pharmacological activity of the drug at the site of action. Drug delivery systems are molecular tools which, without undesired interactions at other sites, target a specific drug receptor. Keeping in view the advantages of the delivery system, rapidly disintegrating dosage forms have been successfully commercialized, and, because of increased patient demand, these dosage forms are expected to become more popular. Modern drug delivery technology has been made possible by advances in polymer science. These advances have resulted in polymers with unique properties. Drug delivery systems are made from a variety of organic and inorganic compounds such as polymers, lipids (liposomes, nanoemulsions, and solid–lipid nanoparticles), self-assembling amphiphilic molecules, dendrimers, and inorganic nanocrystals. In addition, hydrogels are novel delivery systems that have attracted much attention in current pharmaceutical research.

Monolithic packed 96-tips set for high-throughput sample preparation: determination of cyclophosphamide and busulfan in whole blood samples by monolithic packed 96-tips and LC-MS.

A monolithic methacrylate packed 96-tips device was used for the extraction of the busulfan and cyclophosphamide in whole blood samples. Using a packed 96-tips set, a 96-well plate could be handled in about 2 min. The key aspect of the monolithic phase is that monolithic material can offer both good extraction capacity and low-back-pressure properties. The validation of the methodology showed that the accuracy values of quality-control samples were between 99 and 113% for busulfan, and between 103 and 110% for cyclophosphamide. The inter-day precision ranged from 7.0 to 12% for busulfan and from 13 to 16% for cyclophosphamide. The standard calibration curves were obtained within the concentration range 5-2000 nm for busulfan and from 10 to 5000 nm for cyclophosphamide in blood samples. The coefficients of determination were ≥0.99.

Synthesis, pharmacological activity evaluation and molecular modeling of new polynuclear heterocyclic compounds containing benzimidazole derivatives

Novel heterocyclic compounds containing benzimidazole derivatives were synthesized from 2-(1Hbenzimidazol-2-yl) acetonitrile (1) and arylhydrazononitrile derivative 2 was obtained via coupling of 1 with 4-methyl phenyldiazonium salt, which was then reacted with hydroxylamine hydrochloride to give amidooxime derivative 3. This product was cyclized into the corresponding oxadiazole derivative 4 upon reflux in acetic anhydride. Compound 4 was refluxed in DMF in the presence of triethylamine to give the corresponding 5-(1H-benzimidazol-2-yl)-2-p-tolyl-2H-1,2,3-triazol-4-amine 6. Treatment of compound 6 with ethyl chloroformate afforded 2,6-dihydro-2-(4-methylphenyl)-1,2,3-triazolo[4″,5″-4′,5′]pyrimido[1,6-a]benzimidazole-5(4H)-one (8). 1,2-bis(2-cyanomethyl-1H-benzimidazol-1-yl)ethane-1,2-dione (10) was synthesized via the condensation reaction of 2-(1H-benzimidazol-2-yl) acetonitrile (1) and diethyloxalate. The reactivity of compound 10 towards some diamine reagents was studied. The in vitro antimicrobial activity of the synthesized compounds was investigated against several pathogenic bacterial strains such as Escherichia coli O157, Salmonella typhimurium, E. coli O119, S. paratyphi, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. The results of MIC revealed that compounds 12a–c showed the most effective antimicrobial activity against tested strains. On the other hand, compounds 12a, b exhibited high activity against rotavirus Wa strain while compounds 12b, c exhibited high activity against adenovirus type 7. In silico target prediction, docking and validation of the compounds 12a–c were performed. The dialkylglycine decarboxylase bacterial enzyme was predicted as a potential bacterial target receptor using pharmacophorebased correspondence with previous leads; giving the highest normalized scores and a high correlation docking score with mean inhibition concentrations. A novel binding mechanism was predicted after docking using the MOE software and its validation.

Molecular Modeling and Biological Activities of New Potent Antimicrobial, Anti-Inflammatory and Anti-Nociceptive of 5-Nitro Indoline-2-One Derivatives

In recent years, molecular modeling has become an important technique for drug discovery and pharmaceutical science. The objective of this study is to determine the molecular modeling of the antibacterial, anti-inflammatory and anti-nociceptive activities of a new series of pyrazoles, oxadiazoles and sugar hydrazines of 5-nitroindolin-2- one derivatives. The molecular modeling protocol was applied using the MOE (Molecular Operating Environment) software. Synthetic compounds 1, 3, 8, 9, 10 and 12 were the most active compounds, as antibacterial, antiinflammatory and anti-nociceptive activities were studied for the binding affinity of the cyclooxygenase1 (COX1), The glucocorticoid receptor (GR), the cytochrome P450 receptor of 14alfa-sterol demethylases (CYP51) and the dihydroprotease synthase receptor. Molecular modeling studies revealed that the [(methylbenzyl)-5-nitro-2- oxoindolin-3-ylideneamino-benzohydrazide derivative (3) gave a score of (-15.8587 kcal/mol), while 1,3,4-oxadiazol- 2-yl) phenylimino)-1-(methylbenzyl)-5-nitroindolin-2-one derivative (9) gave a higher score (-16.8038 kcal/mol) than flucanazole Co-crystallized gave a score of (-10.2837 kcal/mol). However, the compound (12), D-Arabinose- (methylbenzyl)-5-nitro-2-oxoindolin-(3-ylideneamino) hydrazone derivative gave a score of (-24.6577 kcal/mol) greater than the co-crystallized ligand which gave a score of (-16.6717 kcal/mol).

Spectrophotometric microdetermination of tranexamic acid in pharmaceutical formulation

Background and objectives Tranexamic acid is used to treat various conditions in which there is bleeding or risk of bleeding, such as prostatectomy, dental extraction, menorrhagia, and thrombolytic overdose. Most of the currently available analytical techniques for Tranexamic acid measurement use high-performance liquid chromatography (HPLC) separation or the spectrophotometric method of detection. The aim of the present study was to describe the determination of Tranexamic acid as an active pharmaceutical ingredient in tablets using three accurate and sensitive spectrophotometric methods: the ion-air complex method (method A), the bromination complex method (method B), and the charge transfer complex method (method C). Materials and methods The first method (A) is based on the formation of an ion-pair complex between the basic nitrogen of Tranexamic acid and alizarin red S as an anionic acid dye. The absorbance of the formed complex was measured at λmax equal to 300 nm. The second method (B) is based on the oxidation of Tramexamic acid by N-bromosuccinimide (NBS) and determination of the nonreacted NBS by measurement of the decrease in absorbance of liberated iodine at λmax equal to 520 nm. The third method (C) is based on forming a charge transfer complex with chloranil in absolute ethanol at alkaline pH. The absorbance of the formed charge transfer complex was measured at λmax equal to 330 nm. Linear calibration curves were obtained in the ranges of 2.00-26.00, 2.00-25.00, and 2.00-27.00 μg/ml. The methods showed relative standard deviations of 0.839, 0.952, and 0.984 for methods A, B and C, respectively. Results and conclusion The results showed the suitability, safety, accuracy, and simplicity of these methods for determination of Tranexamic acid as an active pharmaceutical ingredient. The results obtained by the three methods, A, B, and C, is in good agreement with those obtained by the official method. The developed methods were successfully applied to the determination of Tranexamic acid in pharmaceutical preparation (tablets).

Synthesis of new sulfanyl pyrimidin-4(3H)-one and ethyl-2-(pyridin-4yl) methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives under conventional and heterogeneous conditions

Background and objectives Heterocyclic systems with a pyrimidine nucleus display a wide spectrum of biological activities, such as antimicrobial, antiviral, anticancer, antidepressive, anti-inflammatory, antitubercular, diuretic, and anticoagulant. The aim of the present study was the synthesis of new heterocyclic sulfanylpyrimidin-4(3H)-one derivatives by adopting simple and efficient methods, in addition to ethyl-2-(pyridin-4-yl) methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives in excellent yields. Materials and methods The synthesis of the titled sulfanyl pyrimidin-4(3H)-one derivatives was achieved by the reaction of compounds 1a-c with phenacyl bromide, 4-methyl phenacyl bromide, or 4-nitrophenacyl bromide to give 5-(morpholin-4-ylmethyl)-2-oxoethylphenyl-sulfanyl-pyrimidin-4(3H)-ones (2a-c), [(4-methylpiperazin-1-yl) methyl]-2-oxoethylphenyl-sulfanyl-pyrimidin-4(3H)-ones (3a-c), or piperidin-1-yl) methyl]sulfanyl-pyrimidin-4(3H)-ones (4a-c), respectively. In addition, several heterocyclic pyrimidine derivatives such as ethyl-2-((pyridin-4-yl)methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives 6a-h were prepared by the reaction of 1,2 dihydropyrimidone derivatives 5a-h with picolyl chloride using conventional and heterogeneous catalysts such as silica sulfuric acid and CuY-Zeolite. The structures of the synthesized compounds were confirmed by elemental analyses and spectroscopic methods. Results and conclusion A simple and efficient method was used for the synthesis of sulfanyl pyrimidin-4(3H)-one derivatives through reaction with different reagents. Also, ethyl-2-((pyridin-4-yl)methoxy-1,2-dihydro-6-methyl-pyrimidine derivatives were obtained using conventional and heterogeneous conditions in excellent yields.

Antimicrobial, anti-inflammatory, and antinociceptive activities of triazole, pyrazole, oxadiazine, oxadiazole, and sugar hydrazone-5-nitroindoline-2-one derivatives and a study of their computational chemistry ( part II)

Objective The aim of this study (part II) is to evaluate the antibacterial, anti-inflammatory, and antinociceptive activities of a series of 1H-1,2,4-triazol-3-yl)phenylimino)(methylbenzyl)-5-nitroindolin-2-ones, 1H-pyrazole-1-carbonyl)phenylimino)-1-( p -methylbenzyl)-5-nitroindolin-2-ones, 3-(4-(1,3,4-oxadizine-6-one)phenylimino)-1-( p -methylbenzyl)-5-nitroindolin-2-ones, 1,3,4-oxadiazol-2-yl)phenylimino)-1-( p -methylbenzyl)-5-nitroindolin-2-ones and 4-(-1-( p -methylbenzyl)-5-nitro-2-oxoindolin-3-ylideneamino) sugar hydrazone derivatives ( 1–13 ) and, in addition, to investigate their computational chemistry. Methods The synthesized compounds in (part I) 1–9 were evaluated for their antibacterial and antifungal activities using different strains of Gram-positive bacteria ( Bacillus subtilis ), Gram-negative bacteria ( Pseudomonas aeruginosa) , yeast ( Candida albicans ), and four mold fungi ( Fusarium solani , Aspergillus niger , Colletotrichum gloeosporioides , and Phomopsis obscurans ). The anti-inflammatory and antinociceptive activities of compounds 1–13 were evaluated using a hot-plate test, acetic acid-induced writhing in mice, formalin-induced nociception, a tail immersion test, and carrageenan-induced hind paw edema. For computational chemistry, a semiempirical MNDO method (Modified Neglect of Differential Overlap is a semi-empirical method for the quantum calculation of molecular electronic structure in computational chemistry) associated with HyperChem professional 7.5 programs was adapted. Results and conclusion Compounds 4-[(1-( p -methylbenzyl)-5-nitro-2-oxoindolin-3-ylideneamino)] benzohydrazide ( 3 ) and 3-(4-(5-methyl-1,3,4-oxadiazol-2-yl)phenylimino)-1-( p -methylbenzyl)-5-nitroindolin-2-one ( 9 ) showed the highest antibacterial and antifungal activities compared with clotrimazole and sulfamethoxazole as reference drugs. In contrast, compounds ethyl 4-(5-nitro-2-oxoindolin-3-ylideneamino) benzoate ( 1 ), 3-(4-(3-methyl-5-oxo-4,5-dihydro-1H-pyrazole-1-carbonyl) phenylimino)-1-( p -methylbenzyl)-5-nitroindolin-2-one ( 8 ), D-glucose-4-(-1-( p -methylbenzyl)-5-nitro-2-oxoindolin-3-ylideneamino) hydrazone derivative ( 10 ), and D-arabinose-4-(-1-( p -methylbenzyl)-5-nitro-2-oxoindolin-3-ylideneamino) hydrazone derivative ( 12 ) showed significantly high anti-inflammatory and antinociceptive activities when compared with indomethacin and morphine as reference drugs. From the computational chemistry compounds, ethyl 4-(5-nitro-2-oxoindolin-3-ylideneamino) benzoate ( 1 ), ethyl 4-[(1-( p -methylbenzyl)-5-nitro-2-oxoindolin-3-ylideneamino)] benzoate ( 2 ), and 4-[(1-( p -methylbenzyl)-5-nitro-2-oxoindolin-3-ylideneamino)] benzohydrazide ( 3 ) yielded the lowest values of total energy and heat of formation, and had higher stability than other molecules.