Microencapsulation has wide applications in medical, pharmaceutical, and food industries. The parameters affecting the microencapsulation process has to be optimized in order to achieve high efficiency of encapsulation. This study has the objectives of optimizing the process parameters involved in the encapsulation process of Metformin into Guar gum. The process parameters affecting the microencapsulation process of biodegradable polymers, viz. rotation speed (800-1200 rpm), drug to polymer ratio (0.2, 0.4, 0.6), and reaction time (30-90 min) were evaluated and optimized with Response Surface Methodology (RSM) using three level-three factor Central Composite Design (CCD). The P-value 2 <<0.0001 with R = 0.9979 showed highly significant model. The results obtained revealed that particle size increases with increasing drug to polymer ratio and reaction time whereas speed of rotation (rpm) has a negative effect towards the particle size formation. The interaction between the speed of rotation (rpm) and reaction time has been found highly significant, however a minuscule interaction between drug to polymer ratio and speed of rotation (rpm) as well as between drug to polymer ratio and reaction time has been observed. A particle size of 24.73 ± 0.21 μ was obtained at the optimum condition of the process variables generated by the model which was 1156 rpm, drug to polymer ratio of 0.37 and reaction time of 89 minutes.