preparation of chitosan (cs) microspheres as a novel drug delivery vehicle for intranasal immunization using high, medium and low cs molecular weight (mw) was investigated in this study. diphtheria toxoid (dt) was used as a model antigen. the emulsion-solidification method was adopted for microencapsulation of dt.  in the first step, following the purification of semi-crude dt by the ion-exchan...

diphtheria is a fatal disease caused by exotoxin of corynebacterium     diphtheria .  this toxin consists of   two chains, catalytic chain (a) and binding (b) chain. by binding chain (b),   the toxin binds to its receptor on numerous body cells such as myocardial,   kidney and peripheral nerve cells. after entering, catalytic chain (a)   inhibits protein synthesis and finally can cause cell dea...

Preparation of chitosan (CS) microspheres as a novel drug delivery vehicle for intranasal immunization using high, medium and low CS molecular weight (MW) was investigated in this study. Diphtheria toxoid (DT) was used as a model antigen. The emulsion-solidification method was adopted for microencapsulation of DT.  In the first step, following the purification of semi-crude DT by the ion-exchan...

Preparation of chitosan (CS) microspheres as a novel drug delivery vehicle for intranasal immunization using high, medium and low CS molecular weight (MW) was investigated in this study. Diphtheria toxoid (DT) was used as a model antigen. The emulsion-solidification method was adopted for microencapsulation of DT.  In the first step, following the purification of semi-crude DT by the ion-exchan...

By precipitation with acetone at 4 degrees C. a refined diphtheria toxoid was obtained as a dry powder, readily soluble in aqueous solutions. The powder itself appears to be stable. When dissolved in half the original volume of physiological salt solution, the toxoid remained stable, in the cold room, for a period of 7 months. Only toxoids should be used which have been completely detoxified by...

METHODS' for the purification of diphtheria toxoid may be divided into two classes; those which give a moderate degree of purification and a high yield, and those which give a high degree of purification and a yield which varies within wide limits. Among the latter is the method first applied to toxin by Glenny and Walpole [1915] and later modified by Watson and Wallace [1924] for toxin and by ...

The Lf-unit, which is used in the control of diphtheria and tetanus toxoid production and in some countries also to follow immunization of horses for production of antitoxins, has hitherto been defined by means of antitoxin preparations. A diphtheria toxoid and a tetanus toxoid preparation, both freeze-dried, were examined in an international collaborative study for their suitability to serve a...