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Papers by Ali Nasr
International Journal of Applied Pharmaceutics, 2016
Objective: The main purpose of this study was to optimize the different conditions for the prepar... more Objective: The main purpose of this study was to optimize the different conditions for the preparation of self-nanoemulsifying drug delivery system (SNEDDS) for both Irbesartan (IRB) and Olmesartan (OLM). Methods: Based on solubility study and emulsification efficiency, Preliminary investigations of various oils, surfactants and cosurfactants were carried out for selection of the proper SNEDDS ingredients. Pseudoternary phase diagrams were then plotted using series of concentrations to obtain optimum SNEDDS components that identify the efficient self-nanoemulsifying region. Sixteen unloaded SNEEDS formulae were prepared using Capryol 90, Cremophor RH 40 and Transcutol HP as oil, surfactant and cosurfactant respectively. The prepared SNEDDS were evaluated for self-nanoemulsification time, the effect of dilution (with different volumes at different pH values), optical clarity, viscosity, droplet size analysis as well as the polydispersity index (PDI). SNEDDS formulae were also evaluat...
Pharmaceutics, 2016
The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (... more The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) of Olmesartan (OLM) for enhancement of its solubility and dissolution rate. In this study, liquid SNEDDS containing Olmesartan was formulated and further developed into a solid form by the spray drying technique using Aerosil 200 as a solid carrier. Based on the preliminary screening of different unloaded SNEDDS formulae, eight formulae of OLM loaded SNEEDS were prepared using Capryol 90, Cremophor RH40 and Transcutol HP as oil, surfactant and cosurfactant, respectively. Results showed that the mean droplet size of all reconstituted SNEDDS was found to be in the nanometric range (14.91-22.97 nm) with optimum PDI values (0.036-0.241). All formulae also showed rapid emulsification time (15.46˘1.34-24.17˘1.47 s), good optical clarity (98.33%˘0.16%-99.87%˘0.31%) and high drug loading efficiency (96.41%˘1.20%-99.65%˘1.11%). TEM analysis revealed the formation of spherical and homogeneous droplets with a size smaller than 50 nm. In vitro release of OLM from SNEDDS formulae showed that more than 90% of OLM released in approximately 90 min. Optimized SNEDDS formulae were selected to be developed into S-SNEDDS using the spray drying technique. The prepared S-SNEDDS formulae were evaluated for flow properties, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), reconstitution properties, drug content and in vitro dissolution study. It was found that S-SNEDDS formulae showed good flow properties and high drug content. Reconstitution properties of S-SNEDDS showed spontaneous self-nanoemulsification and no sign of phase separation. DSC thermograms revealed that OLM was in solubilized form and FTIR supported these findings. SEM photographs showed smooth uniform surface of S-SNEDDS with less aggregation. Results of the in vitro drug release showed that there was great enhancement in the dissolution rate of OLM. To clarify the possible improvement in pharmacokinetic behavior of OLM S-SNEDDS, plasma concentration-time curve profiles of OLM after the oral administration of optimized S-SNEDDS formula (F3) were compared to marketed product and pure drug in suspension. At all time points, it was observed that OLM plasma concentrations in rats treated with S-SNEDDS were significantly higher than those treated with the drug in suspension and marketed product.
2015 3rd RSI International Conference on Robotics and Mechatronics (ICROM), 2015
The purpose of this paper is to optimize dimensions of KNTU 6-DoF cable driven redundant parallel... more The purpose of this paper is to optimize dimensions of KNTU 6-DoF cable driven redundant parallel manipulators. This manipulator is under investigation for possible high-speed application such as object manipulator. Usage of cable parallel manipulator depends on kinematic characteristic and control algorithm. This optimization is based on different performance indices including the singularity measure, the kinematic sensitivity, the stiffness and free collision workspace. Stiffness of the cable is also taken into consideration because of its effect on kinematic stiffness of moving platform manipulators performance. Points with cable collision, singular or actuator wrench infeasible configuration characteristic are eliminating from entire workspace.
International Journal of Applied Pharmaceutics, 2016
Objective: The main purpose of this study was to optimize the different conditions for the prepar... more Objective: The main purpose of this study was to optimize the different conditions for the preparation of self-nanoemulsifying drug delivery system (SNEDDS) for both Irbesartan (IRB) and Olmesartan (OLM). Methods: Based on solubility study and emulsification efficiency, Preliminary investigations of various oils, surfactants and cosurfactants were carried out for selection of the proper SNEDDS ingredients. Pseudoternary phase diagrams were then plotted using series of concentrations to obtain optimum SNEDDS components that identify the efficient self-nanoemulsifying region. Sixteen unloaded SNEEDS formulae were prepared using Capryol 90, Cremophor RH 40 and Transcutol HP as oil, surfactant and cosurfactant respectively. The prepared SNEDDS were evaluated for self-nanoemulsification time, the effect of dilution (with different volumes at different pH values), optical clarity, viscosity, droplet size analysis as well as the polydispersity index (PDI). SNEDDS formulae were also evaluat...
Pharmaceutics, 2016
The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (... more The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) of Olmesartan (OLM) for enhancement of its solubility and dissolution rate. In this study, liquid SNEDDS containing Olmesartan was formulated and further developed into a solid form by the spray drying technique using Aerosil 200 as a solid carrier. Based on the preliminary screening of different unloaded SNEDDS formulae, eight formulae of OLM loaded SNEEDS were prepared using Capryol 90, Cremophor RH40 and Transcutol HP as oil, surfactant and cosurfactant, respectively. Results showed that the mean droplet size of all reconstituted SNEDDS was found to be in the nanometric range (14.91-22.97 nm) with optimum PDI values (0.036-0.241). All formulae also showed rapid emulsification time (15.46˘1.34-24.17˘1.47 s), good optical clarity (98.33%˘0.16%-99.87%˘0.31%) and high drug loading efficiency (96.41%˘1.20%-99.65%˘1.11%). TEM analysis revealed the formation of spherical and homogeneous droplets with a size smaller than 50 nm. In vitro release of OLM from SNEDDS formulae showed that more than 90% of OLM released in approximately 90 min. Optimized SNEDDS formulae were selected to be developed into S-SNEDDS using the spray drying technique. The prepared S-SNEDDS formulae were evaluated for flow properties, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), reconstitution properties, drug content and in vitro dissolution study. It was found that S-SNEDDS formulae showed good flow properties and high drug content. Reconstitution properties of S-SNEDDS showed spontaneous self-nanoemulsification and no sign of phase separation. DSC thermograms revealed that OLM was in solubilized form and FTIR supported these findings. SEM photographs showed smooth uniform surface of S-SNEDDS with less aggregation. Results of the in vitro drug release showed that there was great enhancement in the dissolution rate of OLM. To clarify the possible improvement in pharmacokinetic behavior of OLM S-SNEDDS, plasma concentration-time curve profiles of OLM after the oral administration of optimized S-SNEDDS formula (F3) were compared to marketed product and pure drug in suspension. At all time points, it was observed that OLM plasma concentrations in rats treated with S-SNEDDS were significantly higher than those treated with the drug in suspension and marketed product.
2015 3rd RSI International Conference on Robotics and Mechatronics (ICROM), 2015
The purpose of this paper is to optimize dimensions of KNTU 6-DoF cable driven redundant parallel... more The purpose of this paper is to optimize dimensions of KNTU 6-DoF cable driven redundant parallel manipulators. This manipulator is under investigation for possible high-speed application such as object manipulator. Usage of cable parallel manipulator depends on kinematic characteristic and control algorithm. This optimization is based on different performance indices including the singularity measure, the kinematic sensitivity, the stiffness and free collision workspace. Stiffness of the cable is also taken into consideration because of its effect on kinematic stiffness of moving platform manipulators performance. Points with cable collision, singular or actuator wrench infeasible configuration characteristic are eliminating from entire workspace.