This work focuses on the identification and optimization of formulation and process variables affecting the characteristics of
nanosuspension, using the Esomeprazole magnesium as a drug candidate. Formulation factors evaluated were ratio of stabilizers to drug
and ratio of anti-solvent to solvent, whereas process parameters were ultrasonication time, power input, stirring speed and process temperature
effect. The test revealed that ratio of the stabilizer to drug and ratio of anti-solvent to solvent has the significant effect on zeta
potential and particle size, whereas different process parameters have significant effect on the particle size and their distribution. In this
study, nanosuspension having the particles as small as 132 (± 20.2) nm was produced by anti solvent precipitation-ultrasonication
method. The zeta potential and PDI (poly dispersity index) of optimized batch were -25.5 (± 2.5) mV and 0.474 (± 0.086), respectively.
The formulated nanosuspension has shown a faster dissolution profile (100% in 60 min), relative to that of micronized esomeprazole suspension
(23.6% in 60 min), mainly due to presence of nanosized particle. The aged nanosuspension exhibited the increase in particle size
from 132 to 187 nm, when it was stored at 25°C/75% relative humidity for six months. Graphically, the aged nanosuspension also
showed the lower release rate than the fresh nanosuspension. However, statistically there was no significant difference (P > 0.05) in rate
of release of aged nanosuspension compared with the fresh nanosuspension.