ポリビニルピロリドン/ポリアクリル酸混合水溶液中におけるクロラムフェニコールの凝集分散挙動

概要

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The flocculation-deflocculation behavior of chloramphenicol (CP) in aqueous solutions of polyvinylpyrrolidone (PVP)/polyacrylic acid (PAA) mixture, which was quite different from the behavior in the solution containing each polymer separately, was studied by means of sedimentation measurements. At a low suspension pH below 5.5 a slow rate of setting and a low sedimentation height ratio (H/H_0) were observed, and microscopic observations showed deflocculation of the CP particles. From pH 5.5 to 6.5 the rate of sedimentation and the sedimentation volume increased rapidly, i.e., the systems in this pH region showed the typical flocculated states. When, however, the suspensions were brought to a higher pH (7 and above) and also when the concentration of PAA was relatively high, the rate of sedimentation was reduced markedly and the values of H/H_0 approached unity. The polymer molecules may be considered as producing a three-dimensional structure in which CP particles were supported and/or producing flocculation of the particles. Both the results of rheological measurements and the polymer adsorption measurements were compatible with the above concept. The effect of neutral salts on the stability of the structure formed in the suspensions was also examined.
公益社団法人日本薬学会の論文
1974-09-25