In recent years, cell cycle and checkpoint pathways regulation are offering new therapeutic approaches against cancer. Isatin, is a well exploited scaffold in the anticancer domain. Accordingly, the current work describes the design and synthesis of two series of (Z)-3-substituted-2-(((E/Z)-5-substituted-2-oxo-1-substituted-indolin-3-ylidene)hydrazinylidene)-thiazolidin-4-ones, 4(a-s) and (E/Z)-1-substituted-3-(((Z)-3-substituted-4-methylthiazol-2(3H)-ylidene)hydrazineylidene)-5-substituted-indolin-2-ones, 5(a-s). The structures of the synthesized molecules were confirmed by spectral and elemental methods of analyses. Pure diastereomers were further identified with 1H-1H-NOESY and confirmed with X-ray crystallography. The target compounds were tested in vitro for their cytotoxicity against three human epithelial cell lines, liver (HepG2), breast (MCF-7), and colon (HT-29) in addition to the diploid human normal cells (WI-38) compared to doxorubicin as a reference drug. Variable cytotoxic effects (IC50 3.29–100 ˆAμmol) were reported on the three cancer cell lines with pronounced selectivity compared to the normal one WI-38. The potency of the most active compounds, 4o, 4s, 5e, 5f, 5l, 5m and 5o (IC50 3.29–9.92 ˆAμmol), in both series associated with the (Z) configurations of N = thiazolidin/ene or one, however, the configuration of the N = isatin moiety seemed to be of no importance to the activity. The tested compounds were grouped for their possible mechanism of action into 4 categories. Compound 4o with no apparent effect on all genes examined. Compounds 4s and 5o affected all genes investigated and seem to have multiple cellular targets; induced the expression of p53 and caspases, and downregulated that of CDK1. Compounds 5l and 5m directly elevated the expression of initiator and effector caspases without going through p53 pathway. Finally, compounds 5e and 5f elevated the expression of p53 and inhibited CDK1. Compounds 4s, 5e, 5f, 5l, 5m, and 5o caused a significant elevation in the activity of cleaved caspase 3 as well. Docking studies on CDK1 revealed that the active molecules bind to the tested enzyme by the same manner of the co-crystallized ligands and the isatinthiazoldinone/ene scaffold is essential for binding of these molecules.

A new, selective and accurate spectrofluorimetric assay has been described for detection of Amisulpride and Memantine hydrochloride in pharmaceutical formulations and real plasma samples. The described assay depends on the reaction between the primary amino group of the selected drugs with acetyl acetone & formaldehyde in an acetate buffer of pH 4.8. The derivatized product showed yellow fluorescence at ex= 418 nm and em= 484.5 nm. The calibration graph was linear in the range of 0.05-0.5 and 0.2-1 µg mL1 for AMS and ME, orderly. The limits of detection were 0.0085 and 0.0153 µg mL1, and the limits of quantitation were 0.026 and 0.0464 µg mL1 for AMS and ME respectively. Validation of the described assay was in consonance with ICH guideline. Due to the sensitivity of the prescribed assay, it permits the determination of selected medications in biological sample quantitatively.

A selective, new, rapid and nondestructive Fourier transform Infrared spectroscopic assay has been developed for simultaneous determination of Memantine hydrochloride and Amisulpride in human plasma and their pharmaceutical formulations without interference from common dugs excipients. A binary mixture of ME and nonselective β-blocker namely; carvidalol has been determined the solid-state by FTIR spectroscopy for the first time. The linear range had been extent from 1.0 to 8.0 and 1.0 to 10.0 μg/mg, for ME and AMS respectively. The detection limits were 0.29 and 0.23 μg/mg while quantitation limits were 0.90 and 0.71 μg/mg for ME and AMS respectively. The developed assay has been validated according to ICH & USP recommendations and successfully applied for quantitative determination of selected drugs in biological fluid.

Two benzimidazole anthelmintic drugs; flubendazole (FBZ) and mebendazole (MBZ), were determined by simple spectrofluorimetric method through complex formation with erythrosine B. The ion-pair formation between the dye and the studied drugs quench the fluorescence activity of the dye which was monitored at 554 nm (ex =527 nm). The reaction was performed in Teorell - Stenhagen buffer solution (pH 2.9). The reduction in the emission value of the fluorescence was proportional to the added drug in a linear range of 0.1–3.5 µg mL−1 for both drugs. The detection limits were 34 and 30 ng mL−1 for FBZ and MBZ respectively. The suggested procedure was validated in accordance with ICH guidelines, with satisfactory results. Several commercially available pharmaceutical formulations containing the drugs were successfully analyzed with no significant interference due the commonly used excipients. In addition, the quenching mechanism was explored with Stern Volmer equation and the quenching of the fluorescence was assumed to proceed through static process. Moreover, the free energy change, ΔG°, for the complex formation reactions were −25.6 and −30.1 KJ mol−1 for FBZ and MBZ, respectively.

Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific side effects. Liposomes can encapsulate hydrophilic and lipophilic drugs in the water compartment and the lipid membrane, respectively. However, typical drug loading capacity of liposomes by passive loading method is less than 1%. The low drug loading efficiency is problematic because it necessitates the use of a large amount of carrier materials that may cause undesirable biological effects. To increase drug loading in liposomes, weusedsupersaturated drug solutionswith gemcitabine (GEM) and doxorubicin (Dox) as examples. The prepared liposomes showed higher drug loading compared with passive loading, maintainedstabilityand provided sustained drug release for 48 hrs.

Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific side effects. Liposomes can encapsulate hydrophilic and lipophilic drugs in the water compartment and the lipid membrane, respectively. However, typical drug loading capacity of liposomes by passive loading method is less than 1%. The low drug loading efficiency is problematic because it necessitates the use of a large amount of carrier materials that may cause undesirable biological effects. To increase drug loading in liposomes, weusedsupersaturated drug solutionswith gemcitabine (GEM) and doxorubicin (Dox) as examples. The prepared liposomes showed higher drug loading compared with passive loading, maintainedstabilityand provided sustained drug release for 48 hrs.

Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific side effects. Liposomes can encapsulate hydrophilic and lipophilic drugs in the water compartment and the lipid membrane, respectively. However, typical drug loading capacity of liposomes by passive loading method is less than 1%. The low drug loading efficiency is problematic because it necessitates the use of a large amount of carrier materials that may cause undesirable biological effects. To increase drug loading in liposomes, weusedsupersaturated drug solutionswith gemcitabine (GEM) and doxorubicin (Dox) as examples. The prepared liposomes showed higher drug loading compared with passive loading, maintainedstabilityand provided sustained drug release for 48 hrs.

Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific side effects. Liposomes can encapsulate hydrophilic and lipophilic drugs in the water compartment and the lipid membrane, respectively. However, typical drug loading capacity of liposomes by passive loading method is less than 1%. The low drug loading efficiency is problematic because it necessitates the use of a large amount of carrier materials that may cause undesirable biological effects. To increase drug loading in liposomes, weusedsupersaturated drug solutionswith gemcitabine (GEM) and doxorubicin (Dox) as examples. The prepared liposomes showed higher drug loading compared with passive loading, maintainedstabilityand provided sustained drug release for 48 hrs.

Liposomes are widely used for systemic delivery of chemotherapeutic agents to reduce their nonspecific side effects. Gemcitabine (Gem) makes a great candidate for liposomal encapsulation due to the short half-life and non-specific side effects; however, it has been difficult to achieve liposomal Gem with high drug loading capacity. Remote loading, which uses a transmembrane pH gradient to induce influx of drug and locks the drug in the core as a sulfate complex, does not serve Gem as efficiently as doxorubicin (Dox) due to the low pKa value of Gem. Existing studies have attempted to improve Gem loading capacity in liposomes by employing lipophilic Gem derivatives or creating a high concentration gradient for active loading into the hydrophilic cores (small volume loading). In this study we combine remote loading approach and small volume loading or hypertonic loading, a new approach to induce the influx of Gem into the preformed liposomes by high osmotic pressure, to achieve a Gem loading capacity of 9.4 – 10.3 wt% in contrast to 0.14 – 3.8 wt% of the conventional methods. Liposomal Gem showed a good stability during storage, sustained-release over 120 h in vitro, enhanced cellular uptake and improved cytotoxicity as compared to free Gem. Liposomal Gem showed a synergistic effect with liposomal Dox on Huh7 hepatocellular carcinoma cells. A mixture of liposomal Gem and liposomal Dox delivered both drugs to the tumor more efficiently than a free drug mixture and showed a relatively good anti-tumor effect in a xenograft model of hepatocellular carcinoma. This study shows that bioactive liposomal Gem with high drug loading capacity can be produced by remote loading combined with additional approaches to increase drug influx into the liposomes.

Liposomes are widely used for systemic delivery of chemotherapeutic agents to reduce their nonspecific side effects. Gemcitabine (Gem) makes a great candidate for liposomal encapsulation due to the short half-life and non-specific side effects; however, it has been difficult to achieve liposomal Gem with high drug loading capacity. Remote loading, which uses a transmembrane pH gradient to induce influx of drug and locks the drug in the core as a sulfate complex, does not serve Gem as efficiently as doxorubicin (Dox) due to the low pKa value of Gem. Existing studies have attempted to improve Gem loading capacity in liposomes by employing lipophilic Gem derivatives or creating a high concentration gradient for active loading into the hydrophilic cores (small volume loading). In this study we combine remote loading approach and small volume loading or hypertonic loading, a new approach to induce the influx of Gem into the preformed liposomes by high osmotic pressure, to achieve a Gem loading capacity of 9.4 – 10.3 wt% in contrast to 0.14 – 3.8 wt% of the conventional methods. Liposomal Gem showed a good stability during storage, sustained-release over 120 h in vitro, enhanced cellular uptake and improved cytotoxicity as compared to free Gem. Liposomal Gem showed a synergistic effect with liposomal Dox on Huh7 hepatocellular carcinoma cells. A mixture of liposomal Gem and liposomal Dox delivered both drugs to the tumor more efficiently than a free drug mixture and showed a relatively good anti-tumor effect in a xenograft model of hepatocellular carcinoma. This study shows that bioactive liposomal Gem with high drug loading capacity can be produced by remote loading combined with additional approaches to increase drug influx into the liposomes.