Commonly used animal experiments for the determination of finished pharmaceutical and biological products
Commonly used animal experiments for the determination of finished pharmaceutical and biological products
The standard based on which the animal experiments for the determination of finished pharmaceutical and biological products are conducted is the current edition of the Chinese Pharmacopoeia, and the animal experiments for the determination of finished pharmaceutical products in the Chinese Pharmacopoeia can be divided into various categories according to different categorization methods. According to the type of the test drugs, animal experiments can be divided into animal experiments for traditional Chinese medicines, animal experiments for chemical medicines and animal experiments for biological products. At present, there are mainly three kinds of animal experiments for the factory inspection of finished pharmaceutical and biological products: pyrogen test (in vivo method, i.e., rabbit detection method), suckling mouse test and abnormal toxicity test.
Operation method
Micronutrient Test
Principle
The basic principle of the suckling rat test is that suckling rats are widely used in experiments on pathogenicity and toxicology due to their imperfect development, especially in drug testing and validation and related scientific research, and the suckling rat test is an important category of experiments.
Materials and Instruments
Materials: Move The basic process of the suckling mouse test can be divided into the following steps: For more product details, please visit Aladdin Scientific website.
① KM or NIH etc. distantly inbred mice;
② Standard feeding box.
A. Animal selection.
Unless otherwise specified, the lactating mouse test generally uses mice from distantly inbred strains such as KM or NIH, which have a large genetic capacity, better reproduction ability and mother's nursing ability than inbred strains, and a lactation rate of more than 80%. It is common for first-born and young females to have a poor appetite and mothering ability, and females after 6 litters are usually eliminated due to reduced nursing ability.
Cautions:
① Genetic factors may affect the killing behavior of mothers or the survival rate of mice. The frequency of killing varies among different strains of experimental mice, and a number of genes related to the ability of mothers to kill or raise offspring have been observed in many mutant strains, knockout mice and transgenic mice.
② Animals need to be acclimatized to the animal laboratory environment prior to testing. If 1 ~ 5 day old suckling mice are used for testing, ordering animals with a direct request for 1~5 day old suckling mice will not allow sufficient acclimatization time for suckling mice and females, and pregnant mice that have been pregnant for a certain period of time should be ordered to allow them to acclimatize to the animal laboratory environment for a period of at least 1 week.
B. Animal Transportation.
Animals should not be transported in disposable paper transport boxes, but should be transported in standard feeding boxes in which the dams have been housed for the entire time, with no change of bedding and a larger transport box with a standard feeding cover. Once the animals are in the laboratory, the bedding should not be changed and the standard box should continue to be used until the end of the experiment.
Note: Mothers have the habit of making pup rearing nests. Transportation in a transport box will mean the destruction of the nests carefully prepared by the mother during pregnancy (about 15 days from 4 days after mating to the day before giving birth).
C. Acclimatization time.
The suckling rat test involves both mother and suckling rats, and the test is conducted during the period of imperfect physiological function of suckling rats and the period of psychological sensitivity of mother rats, so prolonging the acclimatization time to make the animals fully adapt to the new environment is particularly important. Especially in the case of direct ordering of suckling rats, mothers and suckling rats are in a state of stress due to transportation, cage changes, environmental changes and other stimuli, plus the stimulation of experimental operation, the maternal capacity of mothers is weakened and the reaction capacity of suckling rats is weakened, resulting in an increase in the mortality rate of suckling rats.
Note: For rodents, acclimatization may not be necessary if the information provided by the supplier establishes the health status of the animals introduced|into the animal, the production and breeding environment is similar to the animal experimental environment, and measures are taken to isolate the animal from pathogens during transportation.
D. Experimental environment and experimental manipulation.
Stress can cause female rats to neglect, kill, or eat their offspring. Stimuli such as auditory disturbances, litter change operations, and frequent movement of personnel can induce | nervousness in female rats. Test operations should also minimize disturbances to the animals, such as noise, odors, and frequent changes in illumination. Therefore, it is best to use specialized laboratories for the suckling rat test, and laboratory personnel and managers should receive specialized training.
E. Internal environment enrichment.
The positive significance of improving the environmental enrichment of animal rearing for animal welfare and experimental accuracy has been widely recognized abroad, and experimental animal managers have generally incorporated environmental enrichment into the daily management of animals. In general, there is nothing other than bedding in the mouse rearing box. For pregnant or lactating female mice, the lack of nesting materials inhibits their natural instincts to make nests, and the lack of shelter makes them more susceptible to being disturbed by human activities; for newborn suckling mice, the lack of a warm nest will cause them to become ill and possibly die if they climb out of the concentrated area of their littermates without the care of their mothers. Nesting materials should be non-toxic, not bow|up animal damage, fluffy, light and easy to carry, generally use hay, shredded paper, paper strips and toilet paper and other materials.
F. Nest changing animal experiments.
In the daily feeding management, the experimental mice will generally change their nests 1~2 times a week under the conditions of living space stipulated by the national standard, but for the cage box of female mice with suckling mice, some studies have shown that changing the nests too often will affect the survival rate of the suckling mice. In a laboratory setting, humans moving around the room can be viewed as potential predators of mice, especially when direct manipulation of the mother and pups is performed during cage cleaning, and disturbance of the nests and nest making sites may reduce the chances of pup survival. Considering the fact that a litter usually resides in a standard box and does not have much feces and urine in the suckling mouse experiment, the frequency of litter change can be set at every 2~3 weeks, without changing the feeding box, and keeping the nursing litter intact (no change).