Dkl. Xing et al., PHYSICOCHEMICAL AND IMMUNOLOGICAL STUDIES ON THE STABILITY OF FREE AND MICROSPHERE-ENCAPSULATED TETANUS TOXOID IN-VITRO, Vaccine, 14(13), 1996, pp. 1205-1213
The stability of tetanus toroid released from experimental, slow-relea
se microsphere vaccines was compared with that of free toroid under di
fferent conditions over a 3 month period The amount of antigenicity re
maining as measured by ELISA, correlated well with loss of toroid stru
cture, as determined by circular dichroism and fluorescence spectrosco
py, At 37 degrees C and low pH, pH 2.5 for free toxoid, or under the a
cidic conditions generated by the hydrolysis of fast-release microsphe
res, a gradual unfolding of the polypeptide chain was observed within
the first few weeks with more rapid denaturation beyond 30 days. Copyr
ight (C) 1996 Elsevier Science Ltd.