Tiêu đề 13. DETAILED STUDY OF STERILITY TESTING OF DIFFERENT PHARMACEUTICAL PREPARATIONS.pdf ✅

PHARMD GURU Page 1 INTRODUCTION: The tests for sterility are intended for detecting the presence of viable forms of microorganisms in pharmaceutical preparations. A number of products are necessary to be sterilized such as ophthalmic preparations, injections, infusions, implants, syringes, bandages, dressings, needles, surgical instruments etc. and must be checked for the contamination of microorganisms (bacteria and fungi). The test must be carried out in an aseptic area to avoid accidental contamination of the product during the test. The working area in which the test is performed should be monitored regularly by sampling the air and surface of the working area. A pyrogen is defined as, “a fever-producing substance that cause febrile reactions when sufficient amount enter the circulatory system”. Bacterial endotoxin is the most significant pyrogen because of its potency and ubiquity. Bacteria, fungi, malarial parasites and viruses can all act as pyrogen. Bacterial products like streptococcal exotoxins, staphylococcal enterotoxins and bacterial endotoxin lipopolysaccharide (LPS) as well as fungal products can also act as pyrogens. The bacterial endotoxin test has generally replaced by the rabbit pyrogen test in the pharmaceutical applications. Pyrogen test measures the rectal temperature of rabbits, both prior to and after the intravenous injection of a test solution in the ear veins. If the rabbits exhibit febrile responses that exceed established limits, then the test solution is pyrogenic. Rabbits are the best choice because they are inexpensive, easy to handle and have a labile thermoregulatory mechanism. TEST FOR STERILITY: The test for sterility is based upon the principle that if microorganisms are placed in a medium which provides nutritive material and water and kept at a favorable temperature, the microorganisms will grow and their presence can be indicated by turbidity in the originally clear medium. DETAILED STUDY OF STERILITY TESTING OF DIFFERENT PHARMACEUTICAL PREPARATIONS
PHARMD GURU Page 2 The probability of detecting viable microorganisms in the tests for sterility, increases with the number present in the given amount of preparations being examined and according to the species of microorganisms present. Table 11.1 gives guidance on the minimum number of items recommended to be tested in relation to the number of items in the batch (as per I.P.). The external surface of ampoules and closures of vials and bottles should be cleaned with a suitable antimicrobial agent. If the contents are packed in a container under vacuum, sterile air should be admitted by using suitable sterile device. The external surface of ampoules and closures of vials and bottles should be cleaned with a suitable antimicrobial agent. If the contents are packed in a container under vacuum, sterile air should be admitted by using suitable sterile device.
PHARMD GURU Page 3 CULTURE MEDIA: The following media are used for tests of sterility. The composition of media used for sterility test is given in Table 11.2. 1) Fluid thioglycollate medium (FTM): It is used with clear fluid products. FTM is primarily intended for the culture of anaerobic bacteria; however it will also detect aerobic bacteria. If more than the upper one-third of the medium has acquired a pink colour, the medium may be restored once by reheating in a water bath or in free flowing steam until the pink colour disappears and cooling rapidly, taking care to prevent the introduction of non-sterile air into the container. When ready for use, not more than the upper one-tenth of the medium should have a pink colour. 2) Alternative thioglycollate medium (ATM): It is used with turbid or viscid products and for devices having tubes with small lumina. ATM is incubated in such way that, to assure anaerobic conditions. 3) Soyabean casein digest medium (SCDM): SCDM is suitable for the culture of both fungi and aerobic bacteria. Medium 1 and 2 are adjusted to pH 7.1 ± 0.2, medium 3 is adjusted to pH 7.3 ± 0.2 and sterilized by autoclaving at 121°C for 20 minutes. Anaerobic conditions are required for growth of some microbial species (Table 11.3).
PHARMD GURU Page 4 SUITABILITY OF MEDIA: The media used for sterility test should comply the following tests.  Sterility of media: Incubate portions of the fluid thioglycollate medium/alternate thioglycollate medium at 30 to 35°C and soyabean casein digest medium at 20 to 25°C for not less than 14 days and observe the presence of the growth of microorganisms in a sterile media.  Growth promotion test: Test each autoclaved load of media for its growth promoting qualities by separately inoculating duplicate test containers of each medium with about 100 viable microorganisms of each of the strains listed in Table 11.3. The test media are satisfactory if clear evidence of growth appears in all inoculated media containers within specified time. The sterility test is considered invalid if the test medium shows inadequate growth response. TEST FOR BACTERLOSTATIS END FUNGISTASIS (TEST FOR SAMPLE TO BE TESTED AS PER IP 1996): Prepare cultures of bacteria and fungi from the strain of microorganisms mentioned in Table 20.3. Inculate the sterility test media with about 100 viable microorganisms using volumes of media listed in Table 11.4. Add the specific