MAGNETICALLY GUIDED RAT ERYTHROCYTES BEARING ISONIAZID - PREPARATION,CHARACTERIZATION, AND EVALUATION

Rat erythrocytes were loaded with isoniazid and magnetite by the presw ell technique. Various parameters such as drug concentration, magnetit e concentration, and volume of aqueous solution were optimized to stud y the maximum loading of drug into erythrocytes (67.2 +/- 1.6%). The l oaded cells were characterized for drug and magnetite content, hemoglo bin content, percent cell recovery, morphology, osmotic fragility, tur bulence shock, in-vivo drug and hemoglobin efflux, and magnetic respon siveness. No appreciable detrimental effect on cell morphology, osmoti c fragility, and turbulence shock in comparison to normal cells was no ted. However, drug and magnetite showed little detrimental effect on c ells. Drug release from these systems followed approximately zero-orde r kinetics. The drug-and magnetite-loaded cells effectively responded to an external magnetic field of 8.0 +/- 1.0 K.Oe. The in-vivo studies showed that an erythrocyte-based delivery system has potential to inc rease drug concentration many fold at the target site under influence of an external magnetic field The drug-loaded erythrocytes appeared to be promising carriers of isoniazid to infected organ/tissue.