For freeze-dried products, the moisture content is required to be less than or equal to 3%. The high water content of freeze-dried products will cause the product to decompose and shrink.
The main reasons for the high water content of products are:
1. Too much liquid medicine.
The thickness of the liquid medicine is generally 10-15mm, and should not exceed 15mm. If the filling volume is large, you can consider replacing the container with a larger size to reduce the thickness of the liquid medicine.
If the liquid medicine is too thick, the heat transfer effect will be poor during the drying process, which is not conducive to removing the moisture in the product, and the phenomenon of excessive moisture in the product will occur.
2. The dried product absorbs moisture again. For varieties that are easy to absorb moisture, if they are not handled properly after drying, the product will absorb moisture again, which will increase the water content in the product.
If the gas enters the freeze-drying box during deflation, it is necessary to sterilize, filter and dry the gas entering the freeze-drying machine;
The temperature of the product when it is out of the box will also affect the water content of the product, so the temperature of the product when it is out of the box is higher than the clean room temperature to prevent the moisture in the air from condensing on the product. In addition, the high temperature is 2-3 °C, and the relative humidity of the clean room should be strictly controlled below 50%.