Purpose: Domperidone (Dp) is a dopamine (D2) receptor antagonist widely used as gastrointestinal prokinetic and antiemetic drug. It is practically insoluble in water and it is also a weak base having poor dissolution rates at relatively high pH values. The objective of this study is to enhance its dissolution via formulation in gastro-retentive floating tablets. While the system is floating on the gastric contents, the drug is released slowly at a desirable rate imparting a sustained-release effect. Methods: Several hydrophilic and hydrophobic polymers were used in the preparation of tablets matrices. Tablets were evaluated for their physical properties including weight uniformity, drug content, friability, hardness, thickness, floating time as well as the in vitro drug release. Results: The order of sustaining Dp release was exhibited by carbopol 934P > Eudragit RLPO > Eudragit RS100 > Eudragit RL100 > ethyl cellulose> hyroxypropylmethyl cellulose 15000>sodium alginate. Increasing the polymer/Dp ratio in the tablets increased the sustaining effect. Tablets containing 30% and 40 % (w/w) of either HPMC 15000 or sodium alginate showed the best floating properties and release profiles. Analysis of release data revealed that formulae containing cabopol 934P showed zero-order kinetics while the other formulae showed Higuchi model kinetics. All formulae showed non-fickian release pattern. Conclusion: formulation of floating tablets has successfully improved and sustained domperidone release over a time period of 12 hours. This may be beneficial in prolonging the prophylaxis against nausea and vomiting for a longer time eliminating the need for multiple dosing which also improves the patient compliance. Future work includes adding an immediate release component for instant prokinetic effect and in vivo comparative studies.

Purpose: Domperidone (Dp) is a dopamine (D2) receptor antagonist widely used as gastrointestinal prokinetic and antiemetic drug. It is practically insoluble in water and it is also a weak base having poor dissolution rates at relatively high pH values. The objective of this study is to enhance its dissolution via formulation in gastro-retentive floating tablets. While the system is floating on the gastric contents, the drug is released slowly at a desirable rate imparting a sustained-release effect. Methods: Several hydrophilic and hydrophobic polymers were used in the preparation of tablets matrices. Tablets were evaluated for their physical properties including weight uniformity, drug content, friability, hardness, thickness, floating time as well as the in vitro drug release. Results: The order of sustaining Dp release was exhibited by carbopol 934P > Eudragit RLPO > Eudragit RS100 > Eudragit RL100 > ethyl cellulose> hyroxypropylmethyl cellulose 15000>sodium alginate. Increasing the polymer/Dp ratio in the tablets increased the sustaining effect. Tablets containing 30% and 40 % (w/w) of either HPMC 15000 or sodium alginate showed the best floating properties and release profiles. Analysis of release data revealed that formulae containing cabopol 934P showed zero-order kinetics while the other formulae showed Higuchi model kinetics. All formulae showed non-fickian release pattern. Conclusion: formulation of floating tablets has successfully improved and sustained domperidone release over a time period of 12 hours. This may be beneficial in prolonging the prophylaxis against nausea and vomiting for a longer time eliminating the need for multiple dosing which also improves the patient compliance. Future work includes adding an immediate release component for instant prokinetic effect and in vivo comparative studies.

Purpose: Domperidone (Dp) is a dopamine (D2) receptor antagonist widely used as gastrointestinal prokinetic and antiemetic drug. It is practically insoluble in water and it is also a weak base having poor dissolution rates at relatively high pH values. The objective of this study is to enhance its dissolution via formulation in gastro-retentive floating tablets. While the system is floating on the gastric contents, the drug is released slowly at a desirable rate imparting a sustained-release effect. Methods: Several hydrophilic and hydrophobic polymers were used in the preparation of tablets matrices. Tablets were evaluated for their physical properties including weight uniformity, drug content, friability, hardness, thickness, floating time as well as the in vitro drug release. Results: The order of sustaining Dp release was exhibited by carbopol 934P > Eudragit RLPO > Eudragit RS100 > Eudragit RL100 > ethyl cellulose> hyroxypropylmethyl cellulose 15000>sodium alginate. Increasing the polymer/Dp ratio in the tablets increased the sustaining effect. Tablets containing 30% and 40 % (w/w) of either HPMC 15000 or sodium alginate showed the best floating properties and release profiles. Analysis of release data revealed that formulae containing cabopol 934P showed zero-order kinetics while the other formulae showed Higuchi model kinetics. All formulae showed non-fickian release pattern. Conclusion: formulation of floating tablets has successfully improved and sustained domperidone release over a time period of 12 hours. This may be beneficial in prolonging the prophylaxis against nausea and vomiting for a longer time eliminating the need for multiple dosing which also improves the patient compliance. Future work includes adding an immediate release component for instant prokinetic effect and in vivo comparative studies.

Purpose: Domperidone (Dp) is a dopamine (D2) receptor antagonist widely used as gastrointestinal prokinetic and antiemetic drug. It is practically insoluble in water and it is also a weak base having poor dissolution rates at relatively high pH values. The objective of this study is to enhance its dissolution via formulation in gastro-retentive floating tablets. While the system is floating on the gastric contents, the drug is released slowly at a desirable rate imparting a sustained-release effect. Methods: Several hydrophilic and hydrophobic polymers were used in the preparation of tablets matrices. Tablets were evaluated for their physical properties including weight uniformity, drug content, friability, hardness, thickness, floating time as well as the in vitro drug release. Results: The order of sustaining Dp release was exhibited by carbopol 934P > Eudragit RLPO > Eudragit RS100 > Eudragit RL100 > ethyl cellulose> hyroxypropylmethyl cellulose 15000>sodium alginate. Increasing the polymer/Dp ratio in the tablets increased the sustaining effect. Tablets containing 30% and 40 % (w/w) of either HPMC 15000 or sodium alginate showed the best floating properties and release profiles. Analysis of release data revealed that formulae containing cabopol 934P showed zero-order kinetics while the other formulae showed Higuchi model kinetics. All formulae showed non-fickian release pattern. Conclusion: formulation of floating tablets has successfully improved and sustained domperidone release over a time period of 12 hours. This may be beneficial in prolonging the prophylaxis against nausea and vomiting for a longer time eliminating the need for multiple dosing which also improves the patient compliance. Future work includes adding an immediate release component for instant prokinetic effect and in vivo comparative studies.

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.

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.

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.

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.