Замразяване на лиофилизирани продукти

Когато разтворът е бързо замразен (10-50 градус в минута), кристалите остават при размера, който се вижда под микроскопа; напротив Поглъщането на влагата на готовия продукт е сравнително по-силна . лекарствата са предварително замразени в сушилнята за замръзване по два начина: Едното е да се охлади продукта и сушещата фурна едновременно; the other is to cool down the shelf of the drying oven to about -40℃, and then put the product in. The former is equivalent to slow freezing, and the latter is between quick freezing and slow freezing, so it is often used to take into account freeze-drying efficiency and product quality. The disadvantage of this method is that when the product is put into the box, the water vapor in the air will quickly condense on the shelf, and in the early stage of sublimation, if the plate heats up quickly, the sublimation of a large area may exceed the normal load of the condenser. This phenomenon is especially pronounced in summer. The freezing of the product is in a static state. Experience has proved that the phenomenon of supercooling is easy to occur until the temperature of the product has reached the eutectic point. However, the solute is still not crystallized. In order to overcome the supercooling phenomenon, the freezing temperature of the product should be lower than a range below the eutectic point, and it should be kept for a period of time until the product is completely frozen.