Comparative study of encapsulated vildagliptin microparticles produced by spray drying and solvent evaporation technique

ABSTRACT

Vildagliptin (VLG), an antihyperglycemic drug, having high water solubility and shorter elimination half-life. This leads to administer VLG frequently to maintain its therapeutic efficacy. Hence the goal of this work was to formulate sustained release polymeric VLG microparticles by spray drying technique using 3² full factorial design (Design-Expert Software). Ethyl cellulose (EC) and span-80 were used as encapsulating material and surfactant, respectively. This work furthermore assessed the probability of encapsulating VLG by single emulsion oil in oil (o/o) solvent evaporation technique. The resultant microparticles from these two methods were evaluated to demonstrate the significant differences in their particle size, percentage yield, drug loading (DL), encapsulation efficiency (EE), in vitro drug release, surface morphology, and drug–polymer compatibility. EE of microparticles prepared by spray drying and solvent evaporation technique was in the range of 71.42–89.87% and 51.79–64.03%, respectively. The in vitro drug release study from the microparticles prepared by both methods was conducted for 12 h. Microparticles prepared by solvent evaporation technique showed incomplete VLG release in 12 h. To visualize the effects of independent factors (polymer and surfactant amount) on dependent factors (EE and DL), 2D contour and 3D surface plots were constructed. Significant variations in microparticles’ physicochemical properties were observed with two formulation techniques. Optimum EE and sustained drug release of VLG–EC microparticles were conclusive using spray drying and solvent evaporation techniques.

KEYWORDS:

• Ethyl cellulose
• factorial design
• microparticles
• spray drying
• vildagliptin

Acknowledgments

The authors are very thankful to S.P. Pharmaceuticals (Jalgaon, India) for providing vildagliptin as a gift sample.