capmul mcm was gifted by abitec corporation , usa . tween 20 and peg 400 were purchased from sulab chemicals , vadodara , india .
all the other reagents were analytical grade . for the selection of components of microemulsion ,
solubility study was carried out in number of components according to procedure given by lianli et al .
the oil , surfactant and cosurfactant were selected on the basis of solubility of drug in the solvent , hlb value as well as their gras status . to find out the microemulsion region ,
microemulsions having different composition [ table 1 ] were prepared by dissolving the required amount of drug ( 27 mg/ ml ) in a mixture of oil - smix at 405c and after cooling at 305c adding required volume of water .
they were evaluated for globule size , pdi , zeta potential and % transmittance for optimization .
for the selection of components of microemulsion , solubility study was carried out in number of components according to procedure given by lianli et al .
the oil , surfactant and cosurfactant were selected on the basis of solubility of drug in the solvent , hlb value as well as their gras status . to find out the microemulsion region ,
microemulsions having different composition [ table 1 ] were prepared by dissolving the required amount of drug ( 27 mg/ ml ) in a mixture of oil - smix at 405c and after cooling at 305c adding required volume of water .
they were evaluated for globule size , pdi , zeta potential and % transmittance for optimization .
from the solubility data , capmul mcm , tween 20 and polyethylene glycol 400 were selected as oil , surfactant and cosurfactant component respectively as rosuvastatin is having higher solubility in above solvents .
tween 20:peg 400 [ 3:1% w / w ] resulted in higher microemulsion region compared to [ 1:1% w / w ] and [ 2:1% w / w ] .
this indicates that increasing the surfactant concentration , maximum amount of oil can be solubilized .
pseudo - ternary phase diagram table 1 indicates the different batches of microemulsion and results of evaluation parameters .
optimized batch was selected which is having lower globule size , zeta potential , pdi and higher % transmittance .
the logic behind selecting these criteria for optimization is that lower globule size can result in enhanced permeation as well as provide larger surface area for drug release , pdi is the measure of uniformity of the formulation and less than 1 is desirable .
more negative zeta potential is considered as more physical stability of the formulation and % transmittance was selected as higher as it shows the isotropic uniform system . from the results shown in table 1 , batch me-1 ( 5% capmul mcm , 50% smix )
was selected as optimized batch having globule size of 19.56 nm , -2.62 mv zeta potential , 0.334 pdi and 99.2% transmittance .
from the solubility data , capmul mcm , tween 20 and polyethylene glycol 400 were selected as oil , surfactant and cosurfactant component respectively as rosuvastatin is having higher solubility in above solvents .
tween 20:peg 400 [ 3:1% w / w ] resulted in higher microemulsion region compared to [ 1:1% w / w ] and [ 2:1% w / w ] .
this indicates that increasing the surfactant concentration , maximum amount of oil can be solubilized .
optimized batch was selected which is having lower globule size , zeta potential , pdi and higher % transmittance .
the logic behind selecting these criteria for optimization is that lower globule size can result in enhanced permeation as well as provide larger surface area for drug release , pdi is the measure of uniformity of the formulation and less than 1 is desirable .
more negative zeta potential is considered as more physical stability of the formulation and % transmittance was selected as higher as it shows the isotropic uniform system . from the results shown in table 1 , batch me-1 ( 5% capmul mcm , 50% smix )
was selected as optimized batch having globule size of 19.56 nm , -2.62 mv zeta potential , 0.334 pdi and 99.2% transmittance .
present study demonstrates the potential use of microemulsion system for enhancement in solubility and hence bioavailability for the poorly water soluble drug .
 due to very less bioavailability ( 20% ) of rosuvastatin calcium , an attempt was made to develop and optimize microemulsion formulation . 
 capmul mcm , tween 20 and peg 400 were selected as oil , surfactant and cosurfactant respectively as the drug is having higher solubility in them . 
 3:1% w / w s : cos was selected as it gave higher microemulsion area . 
 optimized batch ( me-1 ) was selected having 5% capmul mcm , 50% tween 20:peg 400 and 45% water based on evaluation parameters globule size , zeta potential , pdi , % transmittance . 
Materials and Methods
Solubility study and phase diagram construction
Preparation of microemulsion and optimization
Results and Discussion
Solubility study and phase diagram construction
Preparation and optimization of microemulsion
Conclusion