Abstract

Jayawickrama G. G. D. T.*, Siriwardhene M. A., Karunarathna K. A. A. U., Nadeshkumar A., Pathirana W.

ABSTRACT

The research focuses on encapsulating insulin within autologous erythrocytes to assess the stability of this novel sustained-release drug delivery system. A secondary objective involves proposing a computerized application to streamline the analysis of intraerythrocyte insulin concentrations using UV absorbance measurements. Isolated erythrocytes were treated with concentration series of NaCl to identify the optimum concentration of NaCl for reversible pores. Insulin was then loaded to the cells under simple diffusion. The erythrocytes were resealed with 0.9% NaCl and the stability period of insulin-loaded erythrocytes was studied. A calibration curve of insulin was developed using UV absorption data from a standard dilution series of soluble insulin. The data was used to develop a computerized application to analyze loaded soluble insulin in to erythrocytes. The soluble insulin showed good liner agreement in the range of 0.2 to 0.8 absorbance at 276 nm (r=0.998). The optimum concentration of NaCl solution was 0.7% w/v to effect limited lysis of the erythrocytes. The optimum concentration of soluble insulin was 20 IU/mL to load into the erythrocytes. An insulin amount of 6.97±0.17 IU, 7.28± 0.24 IU, and 7.69±0.49 IU in 10, 20, and 30 minutes of simple diffusion time (p>0.05) had loaded into 1.00 mL of erythrocytes. The stability period for insulin loaded erythrocytes was 72 hours. The 0.7% w/v NaCl solution effectively creates reversible pores on erythrocyte membranes for loading insulin. The hypo-osmolarity based insulin loading process showed the possibility of loading insulin into erythrocytes and using it as a novel insulin delivery system.