Formulation of saquinavir mesylate loaded microparticle by counterion induced aggregation method: Approach by hyperosmotic technique

Objective

The objective of present work is to formulate saquinavir mesylate loaded microparticle by counterion induced aggregation method, employing simultaneous cold temperature and hyperosmotic solution treatment as new and novel technique.

Method

Chitosan was chosen as polycation and smaller molecular electrolytes such as sodium citrate, sodium sulphate and sodium orthophosphate were chosen as polyanions. The resulted aggregated microparticles were subjected to surface morphology, size distribution, in-vitro release and drug excipient interaction study.

Results and discussion

Sodium citrate (SC) and sodium sulphate (SS) were able to form aggregates except sodium orthophosphate (SP), as chitosan forms complexes and depends on pH and pKa of medium. Prepared aggregates were subjected to cold hyperosmotic dextrose solution to provide more mechanical strength. The percentage of entrapped drug was more in SC based microparticle as compared to SS. The SS and SC microparticles had average particle size of 1400 μm and 1200 μm respectively. Also, the SEM study revealed more rough and ridges on surface of SC particle as compared to SS. The higher correlation coefficient (r²) was found with Higuchi's equation for all formulations and formulation SS2 had greater r² value of 0.986 compared to all and obeyed fickian diffusion. There was no such major interaction were found during FTIR and DSC study. In addition, stability study was performed and data showed no significant change in assay value for SS2.

Conclusion

The microparticles prepared by above mentioned method had sufficient mechanical strength and were able to released drug for a period of 30 h. Furthermore in-vivo study and pharmacokinetic study have to carry out.