《USP61微生物限度检查法中英对照》由会员分享，可在线阅读，更多相关《USP61微生物限度检查法中英对照（35页珍藏版）》请在金锄头文库上搜索。
1、61 MICROBIAL LIMIT TESTS This chapter provides tests for the estimation of the number of viable aerobic microorganisms present and for freedom from designated microbial species in pharmaceutical articles of all kinds, from raw materials to the finished forms. An automated method may be substituted f
2、or the tests presented here, provided it has been properly validated as giving equivalent or better results. In preparing for and in applying the tests, observe aseptic precautions in handling the specimens. Unless otherwise directed, where the procedure specifies simply “incubate,” hold the contain
3、er in air that is thermostatically controlled at a temperature between 30 and 35, for a period of 24 to 48 hours. The term “growth” is used in a special sense herein, i.e., to designate the presence and presumed proliferation of viable microorganisms.PREPARATORY TESTING The validity of the results o
4、f the tests set forth in this chapter rests largely upon the adequacy of a demonstration that the test specimens to which they are applied do not, of themselves, inhibit the multiplication, under the test conditions, of microorganisms that may be present. Therefore, preparatory to conducting the tes
5、ts on a regular basis and as circumstances require subsequently, inoculate diluted specimens of the material to be tested with separate viable cultures of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella. This can be done by adding 1 mL of not less than 103 dilution of
6、 a 24-hour broth culture of the microorganism to the first dilution (in pH 7.2 Phosphate Buffer, Fluid SoybeanCasein Digest Medium, or Fluid Lactose Medium) of the test material and following the test procedure. Failure of the organism(s) to grow in the relevant medium invalidates that portion of th
7、e examination and necessitates a modification of the procedure by (1) an increase in the volume of diluent, the quantity of test material remaining the same, or by (2) the incorporation of a sufficient quantity of suitable inactivating agent(s) in the diluents, or by (3) an appropriate combination o
8、f modifications (1) and (2) so as to permit growth of the inocula.The following are examples of ingredients and their concentrations that may be added to the culture medium to neutralize inhibitory substances present in the sample: soy lecithin, 0.5%; and polysorbate 20, 4.0%. Alternatively, repeat
9、the test as described in the preceding paragraph, using Fluid Casein DigestSoy LecithinPolysorbate 20 Medium to demonstrate neutralization of preservatives or other antimicrobial agents in the test material. Where inhibitory substances are contained in the product and the latter is soluble, a suitab
10、le, validated adaptation of a procedure set forth in the section Membrane Filtration under Test for Sterility of the Product to be Examined under Sterility Tests 71, may be used.If in spite of the incorporation of suitable inactivating agents and a substantial increase in the volume of diluent, it i
11、s still not possible to recover the viable cultures described above and where the article is not suitable for employment of membrane filtration, it can be assumed that the failure to isolate the inoculated organism is attributable to the bactericidal activity of the product. This information serves
12、to indicate that the article is not likely to be contaminated with the given species of microorganism. Monitoring should be continued in order to establish the spectrum of inhibition and bactericidal activity of the article.BUFFER SOLUTION AND MEDIA Culture media may be prepared as follows, or dehyd
13、rated culture media may be used provided that, when reconstituted as directed by the manufacturer or distributor, they have similar ingredients and/or yield media comparable to those obtained from the formulas given herein.In preparing media by the formulas set forth herein, dissolve the soluble sol
14、ids in the water, using heat, if necessary, to effect complete solution, and add solutions of hydrochloric acid or sodium hydroxide in quantities sufficient to yield the desired pH in the medium when it is ready for use. Determine the pH at 25 2.Where agar is called for in a formula, use agar that h
15、as a moisture content of not more than 15%. Where water is called for in a formula, use Purified Water.PH 7.2 Phosphate Buffer Stock Solution Dissolve 34 g of monobasic potassium phosphate in about 500 mL of water contained in a 1000-mL volumetric flask. Adjust to pH 7.2 0.1 by the addition of sodiu
16、m hydroxide TS (about 175 mL), add water to volume, and mix. Dispense and sterilize. Store under refrigeration. For use, dilute the Stock Solution with water in the ratio of 1 to 800, and sterilize.Media Unless otherwise indicated, the media should be sterilized by heating in an autoclave (see Steam Sterilization under Sterilization 1211), the exposure time depending on the volume to be sterilized.I. Fluid Casein DigestSoy LecithinPolysorbate 20 Medium
