Process for preparing a therapeutic agent

A process for preparing a therapeutic agent which comprises:

• A. 1. mincing and grinding placenta with water or diluted physiological saline solution to form an emulsion and
• A. 2. acidifying the emulsion with a mixture of aqueous acetic and hydrochloric acid to 0.5 - 2.0 N;
• B. heating the acidified emulsion to 75.degree.- 90.degree. C for 30 - 60 minutes so as to insolubilize a portion of the placental proteins;
• C. 1. after cooling, centrifuging the acidified emulsion of (B) to remove the insolubilized portion and to produce a supernatant,
• C. 2. neutralizing the supernatant with an alkaline solution and
• C 3. centrifuging the neutralized supernatant so as to form a supernatant fluid and an insoluble precipitant;
• D. 1. concentrating the supernatant fluid of (C) 3 to 1/10-1/30 that of its volume under reduced pressure,
• D. 2. dialysing the concentrated fluid with cellulose tubing so as to obtain a dialysate or filtering the concentrated fluid through a membrane filter so as to obtain a filtrate and
• D. 3 concentrating the dialysate or filtrate to 1/100 to 1/200 or 1/5 to 1/10 respectively of its original volume under reduced pressure;
• E. 1. chromatographically absorbing the concentrated dialysate or filtrate on a column of a cross-linked dextran having an exclusion limit of 5000 molecular weight, of 1500 molecular weight or of 700 molecular weight and
• E. 2. eluting the chromatographically absorbed dialysate or filtrate so as to obtain the fraction of distribution coefficient 0.95 to 1.82 in the case of cross-linked dextran of exclusion limit 5000 molecular weight, of distribution coefficient 0.35 to 1.24 in the case of cross-linked dextran of exclusion limit 1500 molecular weight and of distribution coefficient 0.35 to 1.25 in the case of cross-linked dextran of 700 molecular weight;
• and
• F. lyophilizing said fraction.