Weight variation, test

What tests are used to assess the uniformity of the final product Content uniformity, weight variation testing ... 

Paruta, A.N. Breon, T.L. Greene, D.S. Computerized weight-variation testing for uncoated tablets and capsules. 

Test System (Animal) Several mammalian species are used for acute toxicity studies, but the rat is the preferred rodent species. The body weight variation in test animals should not exceed 20% of the mean weight. At least 10 rodents (5 females, 5 males) should be used at each dose level, and females should be nulliparous and nonpregnant. 

The weight variation of animals at the commencement of the study should not exceed 20% of the mean weight. It is also important that wherever a subchronic oral toxicity study is conducted as a preliminary to a long-term study, the same species and strain should be used in all studies. At least 20 animals (1 female, 10 male) should be used for each test dose. In view of the importance of the subchronic oral toxicity study, use of more animals would be advantageous. Females should be nulliparous and nonpregnant. 

Test System To conduct a repeated-dose inhalation toxicity study, different species may be used. However, this guideline is intended primarily for use with rodents. When a rodent is required, the preferred species is the rat. Commonly used laboratory strains of young, healthy animals should be employed. At the commencement of the study, the weight variation of animals should not exceed 20% of the mean body weight. When a repeated-dose inhalation study is conducted as preliminary to a long-term study, the same species should be used in both studies. 

Bosisio, R.G., Huy, H.H. 1976. On a method of correcting for basis weight variations in dielectric moisture tests on paper, butter fats and grease samples. J. Microwave Power 12, 309-317. 

Numerous studies have been made of the mechanical properties of fibrous composites these include recently published papers on impact properties by Izod (1,2, 3,4) and Charpy (5,6) and drop weight (7) tests. We reported the Charpy impact fracture behavior of various glass-polyester composites regarding the effects of temperature (8,9,10), specimen size (8), and fiber orientation (10). This paper describes the effects of the tough-brittle transition in the impact behavior of glass-polyester composites which occurs with a variation of temperature and specimen size. 

During the compression of effervescent tablets, in-process tests are routinely run to monitor the process. These tests include controls of tablet weight, weight variation, thickness, crushing strength, disintegration, and appearance of the tablet. Friability and pH of the solution may be additionally tested. Electronic devices that monitor tablet weight are normally used. 

This test is conducted to establish consistency in the content of active ingredient from tablet to tablet. There are generally two approaches taken in establishing this weight variation or content uniformity. 

Uniformity of dosage units. Generally, acceptance criteria should be set for weight variation, fill volume, and/or uniformity of fill. For powders intended for reconstitution, uniformity of mass testing is generally considered acceptable. 

Healthy animals obtained after quarantine are randomized by sex into the desired test groups so that bias due to minor weight variations and individual idiosyncrasies is not allowed to affect the final result. Doses are carefully cal-... 

Animals should be assigned to groups in a manner that minimizes bias and assures comparability of pertinent variables (for example, weight variation in animals used In a test should not exceed 20% of the mean weight). 

Weight variation is commonly tested for tablets. To perform the test, ten tablets are individually weighed on an appropriate analytical balance. The ten weights are... 

Four types of storage were used wet room 95% RH 20°C, immersion at 20°C, immersion at 40°C and ambient at 65% RH 20°C. Shrinkage and weight variation measurements were monitored over a 90-day period. Mechanical performance was assessed for 5 time points 2, 7, 28, 60 and 90 days. Compressive strength Rc, estimated according to EN 196-1, is the mean value of tests results varying by less than + 10 % from the mean. The 60 and 90-day time points do not correspond to standard requirements, but are of interest considering the reactivity of super sulfated cement. The results obtained were compared to the classification limits specified by the standard. 

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