Effect of Organic Solvents on Particle Size
When anti solvent was 0.4% (w/v) F68 aqueous solution, the effect of various good solvent was investigated. These organic solvents include ethanol, methanol, PEG 400, propylene glycol. The result as mention in Table 16 & Figure 27 showed that the particles prepared by methanol were the smallest (317 nm) among other organic solvents. Ethanol, PEG 400, and propylene glycol produced the particles having the mean particle size of 525nm, 1274nm, 864nm, respectively, which were much higher in comparison of particles produced by methanol. Therefore, methanol was selected as a solvent for preparation of esomeprazole nanosuspensions.
Effect of Stabilizers on Particle Size
In initial screening trials, some …show more content…
The result showed (Table 20) that the zeta potential value of nanosuspensions was increased with the increasing of polymer concentration. However, above the ratio of 13.3, the zeta potential value of nanosuspensions was decreased. This was due to higher concentration of polymer, which produced the hindrance for movement of particles.
Effect of Ratio of Anti - solvent to Solvent
The ratio of anti-solvent to solvent was also played very important role in the formation of nanosize particles, and the result was summarized in Figure 30. When the volume ratio of anti-solvent to solvent increased from 0.5:1 to 2:1, the particle size reduced from 456 nm to 212 nm (Table 19) due to increasing the supersaturation. However, when the volume ratio reached 3:1, no notable changes were obtained on the particle size, as mentioned in Figure 3. Since, organic phase may lead to the instability. Thus, in order to minimize the introduction of the organic solvent, volume ratio of 3:1 was selected in this work.
Effect of Stirring …show more content…
The release profile of crude drug and selected batch (E15) of prepared nanosuspension are shown in (Figure 34). The rate of release of unprocessed esomeprazole was very slow and only 6.8% of the drug was diffused in the first 15 min. This unprocessed drug did not show the complete diffusion during the test period and only 23.6% of the drug was released after 60 min. The formulation of esomeprazole nanosuspension significantly enhanced the diffusion rate, since about 49% of the drug was diffused in 15 min and almost 100% of the drug diffused in the 60 min test period. The results of in vitro release study revealed that the release rate of esomeprazole nanosuspension was enhanced, compared with unprocessed drug, and the release rate significantly improved with the decreasing of particle size, which can be explained by the Noyes - Whitney
When anti solvent was 0.4% (w/v) F68 aqueous solution, the effect of various good solvent was investigated. These organic solvents include ethanol, methanol, PEG 400, propylene glycol. The result as mention in Table 16 & Figure 27 showed that the particles prepared by methanol were the smallest (317 nm) among other organic solvents. Ethanol, PEG 400, and propylene glycol produced the particles having the mean particle size of 525nm, 1274nm, 864nm, respectively, which were much higher in comparison of particles produced by methanol. Therefore, methanol was selected as a solvent for preparation of esomeprazole nanosuspensions.
Effect of Stabilizers on Particle Size
In initial screening trials, some …show more content…
The result showed (Table 20) that the zeta potential value of nanosuspensions was increased with the increasing of polymer concentration. However, above the ratio of 13.3, the zeta potential value of nanosuspensions was decreased. This was due to higher concentration of polymer, which produced the hindrance for movement of particles.
Effect of Ratio of Anti - solvent to Solvent
The ratio of anti-solvent to solvent was also played very important role in the formation of nanosize particles, and the result was summarized in Figure 30. When the volume ratio of anti-solvent to solvent increased from 0.5:1 to 2:1, the particle size reduced from 456 nm to 212 nm (Table 19) due to increasing the supersaturation. However, when the volume ratio reached 3:1, no notable changes were obtained on the particle size, as mentioned in Figure 3. Since, organic phase may lead to the instability. Thus, in order to minimize the introduction of the organic solvent, volume ratio of 3:1 was selected in this work.
Effect of Stirring …show more content…
The release profile of crude drug and selected batch (E15) of prepared nanosuspension are shown in (Figure 34). The rate of release of unprocessed esomeprazole was very slow and only 6.8% of the drug was diffused in the first 15 min. This unprocessed drug did not show the complete diffusion during the test period and only 23.6% of the drug was released after 60 min. The formulation of esomeprazole nanosuspension significantly enhanced the diffusion rate, since about 49% of the drug was diffused in 15 min and almost 100% of the drug diffused in the 60 min test period. The results of in vitro release study revealed that the release rate of esomeprazole nanosuspension was enhanced, compared with unprocessed drug, and the release rate significantly improved with the decreasing of particle size, which can be explained by the Noyes - Whitney