2. This product is soluble in water, but insoluble in ethanol, chloroform or ether.
3. Identification of specific rotation Take this product, dry it at 80℃ for 2 hours, weigh it accurately, add water to dissolve it and dilute it quantitatively to make a solution containing 0. 1ml of this product and 0.02ml of ammonia test solution, and determine it according to law (Appendix ⅵ e), with specific rotation ranging from +52.0 to +52.6.
4. Relative density: 1.768g/cm3 Lactose is widely used as a filler or diluent for tablets and capsules, and sometimes used in freeze-dried products and baby food formulas. Lactose is also used as a diluent for powder inhalers. There are various levels of lactose supply in the market, such as products with different physical properties of particle size and fluidity. For example, the lactose size range selected when filling capsules depends on the model of the capsule filling machine. Usually, in the process of wet granulation and tablet grinding and mixing, lactose with fine particle size should be selected, which is easier to mix with other ingredients and can also play the role of adhesive more effectively. Other applications include: it can be used as a carrier/diluent for inhalants and freeze-dried preparations. Adding lactose to the freeze-dried solution can increase the volume and help the formation of freeze-dried blocks. Lactose is also mixed with sucrose in a ratio close to 1:3 as a sugar coating solution. The method of preparing lactose from milk was patented by 1937. The preparation method of spray-dried lactose by direct compression was patented in 1958. Since then, lactose has been used as the standard reference for all modern direct compression excipients. At present, there are many levels of lactose supply in the market, including anhydrous α-lactose, α-lactose monohydrate and relatively less used β-lactose. Generally speaking, the choice of lactose level depends on the drug dosage form developed. Lactose directly compressed is often used for pole pieces with small drug content, which can save the granulation process. Compared with crystalline lactose and powdered lactose, directly pressed lactose has better fluidity and compressibility, and it contains specially treated pure α -lactose monohydrate and a small amount of amorphous lactose. The function of amorphous lactose is to improve the pressure/hardness ratio of lactose. In addition, some lactose specially produced for direct compression does not contain amorphous raw materials, but may contain glassy components, which has a (bad) impact on improving compressibility. Lactose for direct compression can also be mixed with microcrystalline cellulose and starch, and tablet lubricants such as 0.5%(W/W) magnesium stearate are usually required. In these preparations, the concentration of lactose is 65%~85%. If other excipients used for direct tabletting, such as pregelatinized starch, are replaced, the amount of spray-dried lactose can be less.