Intranasal Zolmitriptan-Loaded Bilosomes with Extended Nasal Mucociliary Transit Time for Direct Nose to Brain Delivery.

This study aimed at delivering intranasal zolmitriptan directly to the brain through preparation of bilosomes incorporated into a mucoadhesive in situ gel with extended nasal mucociliary transit time. Zolmitriptan-loaded bilosomes were constructed through a thin film hydration method applying Box-Behnken design. The independent variables were amount of sodium deoxycholate and the amount and molar ratio of cholesterol/Span® 40 mixture. Bilosomes were assessed for their entrapment efficiency, particle size and in vitro release. The optimal bilosomes were loaded into mucoadhesive in situ gel consisting of poloxamer 407 and hydroxypropyl methylcellulose. The systemic and brain kinetics of Zolmitriptan were evaluated in rats by comparing intranasal administration of prepared gel to an IV solution. Statistical analysis suggested an optimized bilosomal formulation composition of sodium deoxycholate (5 mg) with an amount and molar ratio of cholesterol/Span® 40 mixture of 255 mg and 1:7.7, respectively. The mucoadhesive in situ gel containing bilosomal formulation had a sol-gel temperature of 34.03 °C and an extended mucociliary transit time of 22.36 min. The gelling system possessed enhanced brain bioavailability compared to bilosomal dispersion (1176.98 vs. 835.77%, respectively) following intranasal administration. The gel revealed successful brain targeting with improved drug targeting efficiency and direct transport percentage indices. The intranasal delivery of mucoadhesive in situ gel containing zolmitriptan-loaded bilosomes offered direct nose-to-brain drug targeting with enhanced brain bioavailability.

Development a spectrofluorometric micellar supported encapsulated method for micro determination of silver ion using new 2,6-disubstituted pyridine derivatives.

Herein, the presented manuscript provides for an extensive spectrofluorimetric method for micro determination of silver ion. This established method based on the use of the three synthesized 2,6-disubstituted pyridine derivatives (R1, R2 and R3) through exploiting their high fluorescence emission property. A noticeable effect on the fluorescence emission of the reagents after chelation with Ag (I) was monitored. Its noteworthy that the sensitivity and stability of this method was increased by using micellar medium. After chelation with Ag(I), the fluorescence emission of the ligands R1 and R2 were effectively quenched in a regular manner by increasing Ag(I) concentration. In contrast, an increase of the fluorescence intensity for reagent R3 after addition of Ag (I) was observed. The solvatochromism for all reagents under investigation was examined in different solvent. Furthermore, the chelation between Ag(I) and the and designed pyridine reagents was assessed spectrophotometrically. The optimum conditions for the most stable complexes which give a high signal difference were explored and well-determined. The linear range for determination of silver ion were determined and found to be 0.18-1.16, 0.06-0.59 and 0.18-1.43 µg mL-1 for R1, R2 and R3, respectively. The statistical analytical parameters such as LOD, LOQ, SD of slope, SD of intercept and RDS were calculated. In addition, the developed methods were efficaciously applied for determination of Ag(I) in some water samples. These selective complexation methods found to be in good precision compared to official and reported method as revealed F-test.

Development of nanoemulsion gel drug delivery systems of cetirizine; factorial optimisation of composition, in vitro evaluation and clinical study.

Aim: This work aimed to develop topical nanoemulsion gels of cetirizine, a second-generation antihistamine, to avoid its oral intake drawbacks and enhance skin permeation.Methods: Cetirizine nanoemulsions were formulated and characterised for their particle size, polydispersity index, zeta potential, drug release and drug permeation through rat skin. The optimised formulation, obtained using 23 full factorial design, was incorporated in carbopol and chitosan gels and evaluated clinically for urticaria treatment.Results: The optimised formulation had particle size of 32.015 ± 1.87 nm, polydispersity index of 0.29 ± 0.04, zeta potential of -19.31 ± 0.43 mV, cetirizine percent released of 98.50 ± 1.23% and permeability coefficient of 7.65 cm.h-1. Cetirizine nanoemulsion gels were more effective than their control gels in urticaria treatment with significant decrease in the degree of wheals and itching and higher recovery percent.Conclusion: Cetirizine nanoemulsion topical gels are expected to be a rational and effective tool for avoiding cetirizine oral side effects and targeting the affected skin.

Pemetrexed, Bevacizumab, or the Combination As Maintenance Therapy for Advanced Nonsquamous Non-Small-Cell Lung Cancer: ECOG-ACRIN 5508.

PURPOSE: Pemetrexed or bevacizumab is used for maintenance therapy of advanced nonsquamous non-small-cell lung cancer (NSCLC). The combination of bevacizumab and pemetrexed has also demonstrated efficacy. We conducted a randomized study to determine the optimal maintenance therapy. PATIENTS AND METHODS: Patients with advanced nonsquamous NSCLC and no prior systemic therapy received carboplatin (area under the curve, 6), paclitaxel (200 mg/m2), and bevacizumab (15 mg/kg) for up to four cycles. Patients without progression after four cycles were randomly assigned to maintenance therapy with bevacizumab (15 mg/kg), pemetrexed (500 mg/m2), or a combination of the two agents. The primary end point was overall survival, with bevacizumab serving as the control group. RESULTS: Of the 1,516 patients enrolled, 874 (57%) were randomly assigned after induction therapy to one of the three maintenance therapy groups. With a median follow-up of 50.6 months, median survival with pemetrexed was 15.9 months, compared with 14.4 months with bevacizumab (hazard ratio [HR], 0.86; P = .12); median survival with pemetrexed and bevacizumab was 16.4 months (HR, 0.9; P = .28); median progression-free survival was 4.2, 5.1 (HR, 0.85; P = .06), and 7.5 months (HR, 0.67; P < .001) for the three groups, respectively. Incidence of worst grade 3 to 4 toxicity was 29%, 37%, and 51%, respectively, for bevacizumab, pemetrexed, and the combination regimen. CONCLUSION: Single-agent bevacizumab or pemetrexed is efficacious as maintenance therapy for advanced nonsquamous NSCLC. Because of a lack of survival benefit and higher toxicity, the combination of bevacizumab and pemetrexed cannot be recommended.

Enhancing the Therapeutic Efficacy of Tamoxifen Citrate Loaded Span-Based Nano-Vesicles on Human Breast Adenocarcinoma Cells.

Serious adverse effects and low selectivity to cancer cells are the main obstacles of long term therapy with Tamoxifen (Tmx). This study aimed to develop Tmx-loaded span-based nano-vesicles for delivery to malignant tissues with maximum efficacy. The effect of three variables on vesicle size (Y1), zeta potential (Y2), entrapment efficiency (Y3) and the cumulative percent release after 24 h (Y4) were optimized using Box-Behnken design. The optimized formula was prepared and tested for its stability in different storage conditions. The observed values for the optimized formula were 310.2 nm, - 42.09 mV, 75.45 and 71.70% for Y1, Y2, Y3, and Y4, respectively. The examination using electron microscopy confirmed the formation of rounded vesicles with distinctive bilayer structure. Moreover, the cytotoxic activity of the optimized formula on both breast cancer cells (MCF-7) and normal cells (BHK) showed enhanced selectivity (9.4 folds) on cancerous cells with IC50 values 4.7 ± 1.5 and 44.3 ± 1.3 µg/ml on cancer and normal cells, respectively. While, free Tmx exhibited lower selectivity (2.5 folds) than optimized nano-vesicles on cancer cells with IC50 values of 9.0 ± 1.1 µg/ml and 22.5 ± 5.3 µg/ml on MCF-7 and BHK cells, respectively. The promising prepared vesicular system, with greater efficacy and selectivity, provides a marvelous tool to overcome breast cancer treatment challenges.

Maximizing the Therapeutic Efficacy of Imatinib Mesylate-Loaded Niosomes on Human Colon Adenocarcinoma Using Box-Behnken Design.

This research purposed to formulate an optimized imatinib mesylate (IM)-loaded niosomes to improve its chemotherapeutic efficacy. The influence of 3 formulation factors on niosomal vesicular size (Y1), zeta potential (Y2), entrapment capacity percentage (Y3), the percentage of initial drug release after 2 h (Y4), and the percentage of cumulative drug release after 24 h (Y5) were studied and optimized using Box-Behnken design. Optimum desirability was specified and the optimized formula was prepared, stability tested, morphologically examined, checked for vesicular bilayer formation and evaluated for its in vitro cytotoxicity on 3 different cancer cell lines namely MCF-7, HCT-116, and HepG-2 in addition to 1 normal cell line to ensure its selectivity against cancer cells. The actual responses of the optimized IM formulation were 425.36 nm, -62.4 mV, 82.96%, 18.93%, and 89.45% for Y1, Y2, Y3, Y4, and Y5, respectively. The optimized IM-loaded niosomes confirmed the spherical vesicular shape imaged by both light and electron microscopes and further proven by differential scanning calorimetry. Moreover, the optimized formula exhibited improved stability on storage at 4 ± 2°C and superior efficacy on MCF7, HCT-116, and HepG2 as IC50 values were 6.7, 16.4, and 7.3 folds less than those of free drug, respectively. Interestingly, IC50 of the optimized formula against normal cell line was ranged from 3 to 11 folds higher than in different cancer cells indicating a higher selectivity of the optimized formula to cancer cells. In conclusion, the incorporation of IM in niosomes enhanced its efficacy and selectivity toward cancer cells, presenting a promising tool to fight cancer using this approach.

Sensitive Spectrofluorimetric Study of the Interaction between Europium(III) and 1,2-Phenylenebis(azan-1-yl-1-ylidene) bis(methan-1-yl-1-ylidene)diphenol Schiff Base.

A sensitive and selective spectrofluorimetric method has been developed for the rapid determination of europium(III). This method is based on the formation of nonluminous complex between Eu(III) and a Schiff base reagent N, N'-bis (salicylidene)-1,2-phenylenediamine (PABD) and measuring the fluorescence quenching of Eu(III)-PABD complex at λex/em = 390/577 nm. The fluorescence intensity complex decreased linearly by increasing the Eu(III) concentration in the range of 1.0-13.0 µM. The optimum conditions for the complex formation were determined such as a pH .0 of borate buffer. The limits of detection (LOD) and quantification (LOQ) of Eu(III) were determined and found to be 0.217 and 0.653 µM, respectively. The maximum relative standard deviation of the method for an europium(III) standard of 6.0 µM was 2.07 % (n = 6). The proposed procedures could be applied successfully for the determination of the investigated metal ion in some spiked water samples with a good precision and accuracy compared to official and reported methods as revealed by t- and F-tests.

Determination of rhodium in metallic alloy and water samples using cloud point extraction coupled with spectrophotometric technique.

A new method to estimate rhodium in different samples at trace levels had been developed. Rhodium was complexed with 5-(4'-nitro-2',6'-dichlorophenylazo)-6-hydroxypyrimidine-2,4-dione (NDPHPD) as a complexing agent in an aqueous medium and concentrated by using Triton X-114 as a surfactant. The investigated rhodium complex was preconcentrated with cloud point extraction process using the nonionic surfactant Triton X-114 to extract rhodium complex from aqueous solutions at pH 4.75. After the phase separation at 50°C, the surfactant-rich phase was heated again at 100°C to remove water after decantation and the remaining phase was dissolved using 0.5mL of acetonitrile. Under optimum conditions, the calibration curve was linear for the concentration range of 0.5-75ngmL(-1) and the detection limit was 0.15ngmL(-1) of the original solution. The enhancement factor of 500 was achieved for 250mL samples containing the analyte and relative standard deviations were ⩽1.50%. The method was found to be highly selective, fairly sensitive, simple, rapid and economical and safely applied for rhodium determination in different complex materials such as synthetic mixture of alloys and environmental water samples.

Spectrophotometric determination of iron in environmental and food samples using solid phase extraction.

A simple, selective and highly sensitive extraction method has been developed for the determination of iron(II) spectrophotometrically after solid phase extraction. The absorbance is measured at λmax 644 nm. Beer's law was obeyed up to 450 ng mL(-1) of iron. The molar absorptivity, Sandell's sensitivity, detection and quantification limits were calculated and found to be 1.09×10(5) L mol(-1) cm(-1), 0.51 ng cm(-2), 1.98 and 6.0 ng mL(-1), respectively and compared with parameters obtained without using solid phase extraction method. After reduction of Fe(III) by addition of 2.0 mL of 10% hydroxylamine HCl, the system was applied to the total iron. The interference of various ions has been studied in detail and the statistical evaluation of the experimental results is reported. The proposed methods have been successfully applied for the determination of trace amount of iron in environment water, soil and botanical reference materials with recovery range (98.71-101.51%).

Determination of thallium at ultra-trace levels in water and biological samples using solid phase spectrophotometry.

A new simple, very sensitive, selective and accurate procedure for the determination of trace amounts of thallium(III) by solid-phase spectrophotometry (SPS) has been developed. The procedure is based on fixation of Tl(III) as quinalizarin ion associate on a styrene-divinylbenzene anion-exchange resin. The absorbance of resin sorbed Tl(III) ion associate is measured directly at 636 and 830 nm. Thallium(I) was determined by difference measurements after oxidation of Tl(I) to Tl(III) with bromine. Calibration is linear over the range 0.5-12.0 µg L(-1) of Tl(III) with relative standard deviation (RSD) of 1.40% (n=10). The detection and quantification limits are 150 and 495 ng L(-1) using 0.6 g of the exchanger. The molar absorptivity and Sandell sensitivity are also calculated and found to be 1.31×10(7) L mol(-1)cm(-1) and 0.00156 ng cm(-2), respectively. The proposed procedure has been successfully applied to determine thallium in water, urine and serum samples.

Chromium speciation in environmental samples using a solid phase spectrophotometric method.

A solid phase extraction technique is proposed for preconcentration and speciation of chromium in natural waters using spectrophotometric analysis. The procedure is based on sorption of chromium(III) as 4-(2-benzothiazolylazo)2,2'-biphenyldiol complex on dextran-type anion-exchange gel (Sephadex DEAE A-25). After reduction of Cr(VI) by 0.5 ml of 96% concentrated H(2)SO(4) and ethanol, the system was applied to the total chromium. The concentration of Cr(VI) was calculated as the difference between the total Cr and the Cr(III) content. The influences of some analytical parameters such as: pH of the aqueous solution, amounts of 4-(2-benzothiazolylazo)2,2'-biphenyldiol (BTABD), and sample volumes were investigated. The absorbance of the gel, at 628 and 750 nm, packed in a 1.0 mm cell, is measured directly. The molar absorptivities were found to be 2.11×10(7) and 3.90×10(7) L mol(-1)cm(-1) for 500 and 1000 ml, respectively. Calibration is linear over the range 0.05-1.45 µg L(-1) with RSD of <1.85% (n=8.0). Using 35 mg exchanger, the detection and quantification limits were 13 and 44 ng L(-1) for 500 ml sample, whereas for 1000 ml sample were 8.0 and 27 ng L(-1), respectively. Increasing the sample volume can enhance the sensitivity. No considerable interferences have been observed from other investigated anions and cations on the chromium speciation. The proposed method was applied to the speciation of chromium in natural waters and total chromium preconcentration in microwave digested tobacco, coffee, tea, and soil samples. The results were simultaneously compared with those obtained using an ET AAS method, whereby the validity of the method has been tested.

Optimization and validation of spectrophotometric methods for determination of finasteride in dosage and biological forms.

AIM AND BACKGROUND: Three simple, accurate and sensitive spectrophotometric methods for the determination of finasteride in pure, dosage and biological forms, and in the presence of its oxidative degradates were developed. MATERIALS AND METHODS: These methods are indirect, involve the addition of excess oxidant potassium permanganate for method A; cerric sulfate [Ce(SO4)2] for methods B; and N-bromosuccinimide (NBS) for method C of known concentration in acid medium to finasteride, and the determination of the unreacted oxidant by measurement of the decrease in absorbance of methylene blue for method A, chromotrope 2R for method B, and amaranth for method C at a suitable maximum wavelength, λmax: 663, 528, and 520 nm, for the three methods, respectively. The reaction conditions for each method were optimized. RESULTS: Regression analysis of the Beer plots showed good correlation in the concentration ranges of 0.12-3.84 µg mL-1 for method A, and 0.12-3.28 µg mL-1 for method B and 0.14 - 3.56 µg mL-1 for method C. The apparent molar absorptivity, Sandell sensitivity, detection and quantification limits were evaluated. The stoichiometric ratio between the finasteride and the oxidant was estimated. The validity of the proposed methods was tested by analyzing dosage forms and biological samples containing finasteride with relative standard deviation ≤ 0.95. CONCLUSION: The proposed methods could successfully determine the studied drug with varying excess of its oxidative degradation products, with recovery between 99.0 and 101.4, 99.2 and 101.6, and 99.6 and 101.0% for methods A, B, and C, respectively.

Enhancement of famotidine dissolution rate through liquisolid tablets formulation: in vitro and in vivo evaluation.

Although famotidine was reported to be 7.5 and 20 times more potent than ranitidine and cimetidine, respectively, its oral bioavailability is low and variable; due mainly to its poor aqueous solubility. The purpose of this study was to improve famotidine dissolution through its formulation into liquisolid systems and then to investigate the in vitro and in vivo performance of the prepared liquisolid tablets. The new mathematical model was utilized to formulate various liquisolid powder systems. Both DSC and XRD suggested loss of famotidine crystallinity upon liquisolid formulation which was further confirmed by SEM indicating that even though the drug existed in a solid dosage form, it is held within the powder substrate in a solubilized, almost molecularly dispersed state, which contributed to the enhanced drug dissolution properties. All the tested liquisolid tablet formulations showed higher drug dissolution rates (DR) than the conventional, directly compressed tables. In addition, the selected optimal formula released 78.36% of its content during the first 10 min which is 39% higher than that of the directly compressed tablets. Further, the bioavailability study indicated that the prepared optimal liquisolid formula did not differ significantly from the marketed famotidine tablets concerning Cmax, tmax, and AUC(0-8) at P<0.05.