Domperidone is a dopamine antagonist antiemetic drug, water-insoluble and weakly basic with poor dissolution rates at high pH values. The current study aimed to improve such dissolution via adsorbates and co-adsorbates formulations. Adsorbates of drug with Avicel PH 101, Florite R and Aerosil 200 were prepared in different weight ratios by physical mixing, grinding and solvent deposition methods. Co-adsorbates of drug with Tween 80 and Aerosil 200 were prepared by solvent deposition method in different weight ratios. These systems were characterized using Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), powder X-ray diffractometry (P-XRD) and in-vitro dissolution. The results showed marked enhancement of domperidone dissolution at both pH1.2 and pH6.8 (7 fold and 5 fold, respectively) compared to drug alone.

To overcome the well-known problems encountered with surface fouling of carbon electrodes that occurred with many compounds, we report a simple and rapid method for the preparation of a disposable sensor depending on electrodeposition of porous Cu-microparticles on pencil graphite electrode (Cu-PGE) that can be applied for sensing antiviral compound valacyclovir (VAL). The bare and porous Cu-modified pencil graphite electrodes were characterized by cyclic voltammetry and SEM. The porous Cu-modified pencil graphite electrode displayed distinct electrocatalytic activities in response to the electrochemical redox reaction of Cu2+ ion in the Cu-VAL complex. Adsorptive square wave stripping voltammetry (AdSWV) was used for the direct electrochemical determination of VAL. Under experimental conditions, the modified electrode had a linear response range from 2.0x10-9 M to 1.0x10-8 M VAL with a detection limit of 1.78x10-10 M. The procedure was applied to the assay of VAL in tablets with mean percentage recoveries of 100.28%. The porous Cu-modified pencil graphite electrode (Cu-PGE) is fabricated utilizing a simple single method, and at an extremely low cost with high stability, sensitivity and offering a promising tool for sensing VAL in quality control laboratories and in stability studies.

To overcome the well-known problems encountered with surface fouling of carbon electrodes that occurred with many compounds, we report a simple and rapid method for the preparation of a disposable sensor depending on electrodeposition of porous Cu-microparticles on pencil graphite electrode (Cu-PGE) that can be applied for sensing antiviral compound valacyclovir (VAL). The bare and porous Cu-modified pencil graphite electrodes were characterized by cyclic voltammetry and SEM. The porous Cu-modified pencil graphite electrode displayed distinct electrocatalytic activities in response to the electrochemical redox reaction of Cu2+ ion in the Cu-VAL complex. Adsorptive square wave stripping voltammetry (AdSWV) was used for the direct electrochemical determination of VAL. Under experimental conditions, the modified electrode had a linear response range from 2.0x10-9 M to 1.0x10-8 M VAL with a detection limit of 1.78x10-10 M. The procedure was applied to the assay of VAL in tablets with mean percentage recoveries of 100.28%. The porous Cu-modified pencil graphite electrode (Cu-PGE) is fabricated utilizing a simple single method, and at an extremely low cost with high stability, sensitivity and offering a promising tool for sensing VAL in quality control laboratories and in stability studies.

To overcome the well-known problems encountered with surface fouling of carbon electrodes that occurred with many compounds, we report a simple and rapid method for the preparation of a disposable sensor depending on electrodeposition of porous Cu-microparticles on pencil graphite electrode (Cu-PGE) that can be applied for sensing antiviral compound valacyclovir (VAL). The bare and porous Cu-modified pencil graphite electrodes were characterized by cyclic voltammetry and SEM. The porous Cu-modified pencil graphite electrode displayed distinct electrocatalytic activities in response to the electrochemical redox reaction of Cu2+ ion in the Cu-VAL complex. Adsorptive square wave stripping voltammetry (AdSWV) was used for the direct electrochemical determination of VAL. Under experimental conditions, the modified electrode had a linear response range from 2.0x10-9 M to 1.0x10-8 M VAL with a detection limit of 1.78x10-10 M. The procedure was applied to the assay of VAL in tablets with mean percentage recoveries of 100.28%. The porous Cu-modified pencil graphite electrode (Cu-PGE) is fabricated utilizing a simple single method, and at an extremely low cost with high stability, sensitivity and offering a promising tool for sensing VAL in quality control laboratories and in stability studies.

To overcome the well-known problems encountered with surface fouling of carbon electrodes that occurred with many compounds, we report a simple and rapid method for the preparation of a disposable sensor depending on electrodeposition of porous Cu-microparticles on pencil graphite electrode (Cu-PGE) that can be applied for sensing antiviral compound valacyclovir (VAL). The bare and porous Cu-modified pencil graphite electrodes were characterized by cyclic voltammetry and SEM. The porous Cu-modified pencil graphite electrode displayed distinct electrocatalytic activities in response to the electrochemical redox reaction of Cu2+ ion in the Cu-VAL complex. Adsorptive square wave stripping voltammetry (AdSWV) was used for the direct electrochemical determination of VAL. Under experimental conditions, the modified electrode had a linear response range from 2.0x10-9 M to 1.0x10-8 M VAL with a detection limit of 1.78x10-10 M. The procedure was applied to the assay of VAL in tablets with mean percentage recoveries of 100.28%. The porous Cu-modified pencil graphite electrode (Cu-PGE) is fabricated utilizing a simple single method, and at an extremely low cost with high stability, sensitivity and offering a promising tool for sensing VAL in quality control laboratories and in stability studies.

An electrochemical sensor for acyclovir (ACV) based on polymerization of β-cyclodextrin (β-CD) on electrochemically pretreated pencil graphite electrode (PGE) was built for the first time. A synergistic effect of β-CD was used to construct this sensor for quantification of this important drug. Scanning electron microscope (SEM) images show that polymer of β-CD has been successfully modified on the electrode. Square wave voltammetry (SWV) exhibited two linear dynamic ranges of 5x10-8 to 6x10-7 M and 1x10-6 to 9x10-6 M of ACV for its oxidation and the detection limit was found to be as low as 7.59x10-9 M of ACV. The parameters affecting ACV oxidation were investigated. The prepared electrodes showed good fabrication reproducibility. The analytical applications of the prepared electrodes were tested by using ACV dosage forms and human urine as a real sample. The SWV analysis has been successfully applied to pharmacokinetic studies of ACV in health human volunteers after oral administration of a single dose of Zovirax suspension (400 mg/5 mL).

An electrochemical sensor for acyclovir (ACV) based on polymerization of β-cyclodextrin (β-CD) on electrochemically pretreated pencil graphite electrode (PGE) was built for the first time. A synergistic effect of β-CD was used to construct this sensor for quantification of this important drug. Scanning electron microscope (SEM) images show that polymer of β-CD has been successfully modified on the electrode. Square wave voltammetry (SWV) exhibited two linear dynamic ranges of 5x10-8 to 6x10-7 M and 1x10-6 to 9x10-6 M of ACV for its oxidation and the detection limit was found to be as low as 7.59x10-9 M of ACV. The parameters affecting ACV oxidation were investigated. The prepared electrodes showed good fabrication reproducibility. The analytical applications of the prepared electrodes were tested by using ACV dosage forms and human urine as a real sample. The SWV analysis has been successfully applied to pharmacokinetic studies of ACV in health human volunteers after oral administration of a single dose of Zovirax suspension (400 mg/5 mL).

An electrochemical sensor for acyclovir (ACV) based on polymerization of β-cyclodextrin (β-CD) on electrochemically pretreated pencil graphite electrode (PGE) was built for the first time. A synergistic effect of β-CD was used to construct this sensor for quantification of this important drug. Scanning electron microscope (SEM) images show that polymer of β-CD has been successfully modified on the electrode. Square wave voltammetry (SWV) exhibited two linear dynamic ranges of 5x10-8 to 6x10-7 M and 1x10-6 to 9x10-6 M of ACV for its oxidation and the detection limit was found to be as low as 7.59x10-9 M of ACV. The parameters affecting ACV oxidation were investigated. The prepared electrodes showed good fabrication reproducibility. The analytical applications of the prepared electrodes were tested by using ACV dosage forms and human urine as a real sample. The SWV analysis has been successfully applied to pharmacokinetic studies of ACV in health human volunteers after oral administration of a single dose of Zovirax suspension (400 mg/5 mL).

An electrochemical sensor for acyclovir (ACV) based on polymerization of β-cyclodextrin (β-CD) on electrochemically pretreated pencil graphite electrode (PGE) was built for the first time. A synergistic effect of β-CD was used to construct this sensor for quantification of this important drug. Scanning electron microscope (SEM) images show that polymer of β-CD has been successfully modified on the electrode. Square wave voltammetry (SWV) exhibited two linear dynamic ranges of 5x10-8 to 6x10-7 M and 1x10-6 to 9x10-6 M of ACV for its oxidation and the detection limit was found to be as low as 7.59x10-9 M of ACV. The parameters affecting ACV oxidation were investigated. The prepared electrodes showed good fabrication reproducibility. The analytical applications of the prepared electrodes were tested by using ACV dosage forms and human urine as a real sample. The SWV analysis has been successfully applied to pharmacokinetic studies of ACV in health human volunteers after oral administration of a single dose of Zovirax suspension (400 mg/5 mL).

A validated simple, novel, and rapid spectrofluorimetric method was developed for the determination of some non-sedating antihistamines (NSAs); namely cetirizine (CTZ), ebastine (EBS), fexofenadine (FXD), and loratadine (LOR). The method is based on measuring the native fluorescence of the cited drugs after protonation in acidic media and studying their quantitative fluorescence intensity – structure relationships. There was a linear relationship between the relative fluorescence intensity and the concentration of the investigated drug. Under the optimal conditions, the linear ranges of calibration curves for the determination of the studied NSAs were 0.10–2.0, 0.20–6.0, and 0.02–1.0 μg/mL for (CTZ, FXD), (EBS), and (LOR); respectively. The factors affecting the protonation of the studied drugs were carefully studied and optimized. The method was validated according to ICH guidelines. The suggested method is applicable for the determination of the four investigated drugs in bulk and pharmaceutical dosage forms with excellent recoveries (97.67–103.80 %). Quantitative relationships were found between the relative fluorescence intensities of the protonated drugs and their physicochemical parameters namely: the pKa, log P, connectivity indexes (χv)andtheirsquares. Regression equations (76) were obtained and not previously reported. Six of these equations were highly significant and used for the prediction of RFI of the studied NSAs.