The effect of adding surfactants to electrolyte containing rabeprazole sodium (RAB sodium) on its voltammetric response at pencil graphite electrode (PGE) was explored. The current signal due to the oxidation process as a function of the amount of the cited drug, pH of the medium, type of surfactant and accumulation time at the electrode surface was evaluated. The use of sodium dodecyl sulphate in the presence of Britton-Robinson buffer (pH=6.0) for the electrochemical determination of RAB sodium using cyclic voltammetry (CV) and Square wave adsorptive stripping voltammetry (SWAdSV) at PGE was studied. The oxidation peak current has varied linearly with the drug concentration over the range of 0.006-2.5×10-7 M and 0.5-250 μM using SWAdSV and CV, respectively. The limit of detection was found to be 0.2 nM and 0.18 μM using SWAdSV and CV, respectively. The validity of the proposed method for the determination of the studied drug in pure, pharmaceutical formulation in addition to urine was conducted.

The effect of adding surfactants to electrolyte containing rabeprazole sodium (RAB sodium) on its voltammetric response at pencil graphite electrode (PGE) was explored. The current signal due to the oxidation process as a function of the amount of the cited drug, pH of the medium, type of surfactant and accumulation time at the electrode surface was evaluated. The use of sodium dodecyl sulphate in the presence of Britton-Robinson buffer (pH=6.0) for the electrochemical determination of RAB sodium using cyclic voltammetry (CV) and Square wave adsorptive stripping voltammetry (SWAdSV) at PGE was studied. The oxidation peak current has varied linearly with the drug concentration over the range of 0.006-2.5×10-7 M and 0.5-250 μM using SWAdSV and CV, respectively. The limit of detection was found to be 0.2 nM and 0.18 μM using SWAdSV and CV, respectively. The validity of the proposed method for the determination of the studied drug in pure, pharmaceutical formulation in addition to urine was conducted.

Candesartan cilexetil is widely used in the management of hypertension and heart failure. The drug delivery encounters obstacles of poor aqueous solubility, efflux by intestinal P-glycoprotein and vulnerability to enzymatic degradation in small intestine. Self-nanoemulsifying drug delivery systems (SNEDDS) loaded with candesartan cilexetil were successfully developed to overcome such obstacles. Preliminary screening was carried out to select proper surfactant, co-surfactant and oil combination for successful SNEDDS formulation. All screened excipients were reported for their P-glycoprotein and cytochrome P450 3A4 (CYP3A4) modulation activity. Ternary and pseudo ternary diagrams were constructed to optimize the system. Peppermint oil and clove oil showed a high emulsification ability. The nature of obtained dispersions was identified to be nanoemulsions. Twenty-four formulations were evaluated for stability, robustness to dilution and self-emulsification efficiency. All formulations showed a very short emulsification time of less than 2 min. The emulsification efficiency was significantly superior at pH 6.8, at which the largest self-emulsifying region was also observed. Eight formulations were selected for further characterization according to cloud point measurement; mean droplet size, poly dispersity index (PDI) and zeta potential determination in addition to in vitro drug release study. All selected formulations showed very high cloud points (70-90oC), ultrafine mean droplet size (12 ±1.4 to 24.5 ± 2.13 nm), very low PDI values (0.015-0.1305) and almost a complete drug release after 12 h. Formulation F15 (Peppermint oil 55% w/w: Cremophor RH40 25% w/w: Labrasol 20% w/w) was selected for further characterization. Its droplet size showed robustness to different dilution folds with different media and its TEM photograph showed spherical particles without any apparent aggregation even after 24 h. Formulation F15 successfully controlled the systolic blood pressure of hypertensive rats for 24 h with the maximum effect was observed after 2 h. These results indicate that, SNEDDS could be promising delivery systems with a rapid onset of action and prolonged therapeutic effect of candesartan cilexetil.

Candesartan cilexetil is widely used in the management of hypertension and heart failure. The drug delivery encounters obstacles of poor aqueous solubility, efflux by intestinal P-glycoprotein and vulnerability to enzymatic degradation in small intestine. Self-nanoemulsifying drug delivery systems (SNEDDS) loaded with candesartan cilexetil were successfully developed to overcome such obstacles. Preliminary screening was carried out to select proper surfactant, co-surfactant and oil combination for successful SNEDDS formulation. All screened excipients were reported for their P-glycoprotein and cytochrome P450 3A4 (CYP3A4) modulation activity. Ternary and pseudo ternary diagrams were constructed to optimize the system. Peppermint oil and clove oil showed a high emulsification ability. The nature of obtained dispersions was identified to be nanoemulsions. Twenty-four formulations were evaluated for stability, robustness to dilution and self-emulsification efficiency. All formulations showed a very short emulsification time of less than 2 min. The emulsification efficiency was significantly superior at pH 6.8, at which the largest self-emulsifying region was also observed. Eight formulations were selected for further characterization according to cloud point measurement; mean droplet size, poly dispersity index (PDI) and zeta potential determination in addition to in vitro drug release study. All selected formulations showed very high cloud points (70-90oC), ultrafine mean droplet size (12 ±1.4 to 24.5 ± 2.13 nm), very low PDI values (0.015-0.1305) and almost a complete drug release after 12 h. Formulation F15 (Peppermint oil 55% w/w: Cremophor RH40 25% w/w: Labrasol 20% w/w) was selected for further characterization. Its droplet size showed robustness to different dilution folds with different media and its TEM photograph showed spherical particles without any apparent aggregation even after 24 h. Formulation F15 successfully controlled the systolic blood pressure of hypertensive rats for 24 h with the maximum effect was observed after 2 h. These results indicate that, SNEDDS could be promising delivery systems with a rapid onset of action and prolonged therapeutic effect of candesartan cilexetil.

Candesartan cilexetil is widely used in the management of hypertension and heart failure. The drug delivery encounters obstacles of poor aqueous solubility, efflux by intestinal P-glycoprotein and vulnerability to enzymatic degradation in small intestine. Self-nanoemulsifying drug delivery systems (SNEDDS) loaded with candesartan cilexetil were successfully developed to overcome such obstacles. Preliminary screening was carried out to select proper surfactant, co-surfactant and oil combination for successful SNEDDS formulation. All screened excipients were reported for their P-glycoprotein and cytochrome P450 3A4 (CYP3A4) modulation activity. Ternary and pseudo ternary diagrams were constructed to optimize the system. Peppermint oil and clove oil showed a high emulsification ability. The nature of obtained dispersions was identified to be nanoemulsions. Twenty-four formulations were evaluated for stability, robustness to dilution and self-emulsification efficiency. All formulations showed a very short emulsification time of less than 2 min. The emulsification efficiency was significantly superior at pH 6.8, at which the largest self-emulsifying region was also observed. Eight formulations were selected for further characterization according to cloud point measurement; mean droplet size, poly dispersity index (PDI) and zeta potential determination in addition to in vitro drug release study. All selected formulations showed very high cloud points (70-90oC), ultrafine mean droplet size (12 ±1.4 to 24.5 ± 2.13 nm), very low PDI values (0.015-0.1305) and almost a complete drug release after 12 h. Formulation F15 (Peppermint oil 55% w/w: Cremophor RH40 25% w/w: Labrasol 20% w/w) was selected for further characterization. Its droplet size showed robustness to different dilution folds with different media and its TEM photograph showed spherical particles without any apparent aggregation even after 24 h. Formulation F15 successfully controlled the systolic blood pressure of hypertensive rats for 24 h with the maximum effect was observed after 2 h. These results indicate that, SNEDDS could be promising delivery systems with a rapid onset of action and prolonged therapeutic effect of candesartan cilexetil.

Candesartan cilexetil is widely used in the management of hypertension and heart failure. The drug delivery encounters obstacles of poor aqueous solubility, efflux by intestinal P-glycoprotein and vulnerability to enzymatic degradation in small intestine. Self-nanoemulsifying drug delivery systems (SNEDDS) loaded with candesartan cilexetil were successfully developed to overcome such obstacles. Preliminary screening was carried out to select proper surfactant, co-surfactant and oil combination for successful SNEDDS formulation. All screened excipients were reported for their P-glycoprotein and cytochrome P450 3A4 (CYP3A4) modulation activity. Ternary and pseudo ternary diagrams were constructed to optimize the system. Peppermint oil and clove oil showed a high emulsification ability. The nature of obtained dispersions was identified to be nanoemulsions. Twenty-four formulations were evaluated for stability, robustness to dilution and self-emulsification efficiency. All formulations showed a very short emulsification time of less than 2 min. The emulsification efficiency was significantly superior at pH 6.8, at which the largest self-emulsifying region was also observed. Eight formulations were selected for further characterization according to cloud point measurement; mean droplet size, poly dispersity index (PDI) and zeta potential determination in addition to in vitro drug release study. All selected formulations showed very high cloud points (70-90oC), ultrafine mean droplet size (12 ±1.4 to 24.5 ± 2.13 nm), very low PDI values (0.015-0.1305) and almost a complete drug release after 12 h. Formulation F15 (Peppermint oil 55% w/w: Cremophor RH40 25% w/w: Labrasol 20% w/w) was selected for further characterization. Its droplet size showed robustness to different dilution folds with different media and its TEM photograph showed spherical particles without any apparent aggregation even after 24 h. Formulation F15 successfully controlled the systolic blood pressure of hypertensive rats for 24 h with the maximum effect was observed after 2 h. These results indicate that, SNEDDS could be promising delivery systems with a rapid onset of action and prolonged therapeutic effect of candesartan cilexetil.

A pencil graphite electrode modified with poly (bromocresol green (BCG)) was prepared by electro-polymerization process for the determination of pantoprazole sodium. The surface morphology and structure of poly (BCG) film were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The determination of pantoprazole sodium in Britton–Robinson buffer (pH 7.0) was carried out by square wave adsorptive stripping voltammetric technique. Under optimum conditions, the linear response of the peak with concentration of the cited drug was in the range of 6.6–360×10−8M with limit of detection of 2.2×10−8 M. Moreover, the poly (BCG)-modified electrode has been successfully applied to determine pantoprazole sodium in tablets, vials and during pharmacokinetic studies.

A pencil graphite electrode modified with poly (bromocresol green (BCG)) was prepared by electro-polymerization process for the determination of pantoprazole sodium. The surface morphology and structure of poly (BCG) film were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The determination of pantoprazole sodium in Britton–Robinson buffer (pH 7.0) was carried out by square wave adsorptive stripping voltammetric technique. Under optimum conditions, the linear response of the peak with concentration of the cited drug was in the range of 6.6–360×10−8M with limit of detection of 2.2×10−8 M. Moreover, the poly (BCG)-modified electrode has been successfully applied to determine pantoprazole sodium in tablets, vials and during pharmacokinetic studies.

A pencil graphite electrode modified with poly (bromocresol green (BCG)) was prepared by electro-polymerization process for the determination of pantoprazole sodium. The surface morphology and structure of poly (BCG) film were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The determination of pantoprazole sodium in Britton–Robinson buffer (pH 7.0) was carried out by square wave adsorptive stripping voltammetric technique. Under optimum conditions, the linear response of the peak with concentration of the cited drug was in the range of 6.6–360×10−8M with limit of detection of 2.2×10−8 M. Moreover, the poly (BCG)-modified electrode has been successfully applied to determine pantoprazole sodium in tablets, vials and during pharmacokinetic studies.

The crotonases comprise a widely-distributed enzyme superfamily that has multiple roles in both primary and secondary metabolism. Many crotonases employ oxyanion hole-mediated stabilisation of intermediates to catalyse reaction of coenzyme A (CoA) thioester substrates (e.g., malonyl-CoA, α,β-unsaturated CoA esters) with both nucleophiles and, in the case of enolate intermediates, with varied electrophiles. Reactions of crotonases that proceed via a stabilized oxyanion intermediate include the hydrolysis of substrates including proteins, as well as hydration, isomerization, nucleophilic aromatic substitution, Claisen-type reactions, and cofactor-independent oxidation reactions. The crotonases have a conserved fold formed from a central β-sheet core surrounded by α-helices, which typically oligomerize to form a trimer, or dimer of trimers. The presence of a common structural platform and a mechanism involving intermediates with diverse reactivity implies that the crotonases have considerable potential for biocatalysis and synthetic biology, as supported by pioneering protein engineering studies on them. In this Perspective, we give an overview of crotonase diversity and structural biology, then illustrate the scope of crotonase catalysis and potential for biocatalysis.