Characterization of CS-FP micro-nano spheres

In order to decide the amount of flurbiprofen in drug loaded spheres, drug entrapment efficiency study was carried out by modification of method of Kawadkar and Chauhan.¹⁴ For this purpose, 10 mg of CS-FP spheres was weighted and ingested 5 mL of 3N hydrochloride. It was stirred using magnetic stirrer at 50°C for 1 h and cooled up to the room temperature. The mixture was taken into the extraction flask and 5 mL of chloroform was added to mixture for extraction process. It was strongly shaken to complete extraction of flurbiprofen. After the separating of two phases, organic extract was distinguished from the other phase. Chloroform was completely evaporated at 70°C. The organic extract was dissolved in ethanol and filtered using 125 µm pore size filter membrane. 0.2 mL of clear solution was diluted to 5 mL. The absorbance of filtered clear solution was measured at 247 nm. Entrapment efficiency was calculated using equation [1] given below²²:

%EE= Calculated amount of flurbiprofenTotal amount of flurbiprofen x100