Dear friends i will like to provid eyou details about carring out sterility test in pharmaceuticals
The Tests for sterility must be performed on all parental preparative viz injectables IV etc,and for some pharmaceuticals which are issued as sterile.
The whole batch of preparation can not be tested for sterility hence test is carried out on randomly selected samples. The inference is based on the results of test complete history of batch , and experience gained in sterilization procedures and testing. If the sample passes the Test for sterility it is known that whole of the batch from which sample is drown has been subjected to the recognized sterilization proceeds for , then the batch may be considered, safe for issue and use.
It does not mean that the batch is sterile as a whole beyond doubt
Test for sterility is passed on principle that when bacteria when placed in medium provide nutrients and water incubated at suitable temp. The organisms will grow, their presence is indicated by turbidity in originally clear medium.
How to do Sampling: The test mast be applied for sample drawn from each batch, no. of containers taken, must be 2% or 20% which ever greater. In case of production sterilized by steam under pressure. In final scaled container, samples from each Sterilizes should be taken. Each should be represented of all layers of the sterilizer. In case of ascetically sealed container, pickup samples at regular interats throughout each filling operation and Sample save taken from final container c volume of 2 ml or more 1ml is taken for each test. It the samples are solid and each container contains 100mg or more 15mg is taken for test. It contents are less they are halved and taken for test.
Media: Media employed for test must be capable of promoting vigorous growth of small no of contaminating aerobic contains a substance c reduce red ox potential of medium. e.g.-
Na-thioglycollate or thioglycolic acid.
some times fluid thioglycoltate medium is priscribed which contain a redox indicator as a medium for aerobic and anaerobic org. Sometimes sufficient heat coagulated muscle is added to form 1cm layer at the bottom of the tube or 0.5% agar is used. fluid thio-glycoute medium with reassurance red ox indicator is best , As medium for aerobic and anaerobic organism and for clear products. Alternate thioglycolate medium is used for testing tar bid or viscid pdts. So yabean casein digest medium is recommended for defecting small no. of aerobic bact. Fungi subouraudi medium can also be used for fungi.
Controlle: Two types of controllers are kept for test for sterility.
1) To ensure sterility of the medium c is designated as negative controlle.
2) To determine suitability of medium is designated as +ve controlle. S. curves, clostridium, saprogenic Candida alb cans are test organism c are in culated
In to aerobic and anaerobic and fungal media respectively.
Incubation: Aerobic and anaerobic media are incubated for not less than days for 30-370c. Medium for fungus incubated at 20 to 250c for not less than 10 days.
Sterility tests for specific preparation.
1) Preparation containing: Bacteria static agent must be either inoculated or diluted is sterile diluents to a concentration c will not in habite the growth of organism.
eg. Phenyl mercuric nitrate is inactivated by thioylycolate phenol, chorocresol is to be diluted.
Preparations containing antibiotics:
As antibiotics are active at very less dilution they are in activated before testing or the process is modified.
A] Penicillin can be inactivated by enzyme penicillin’s. In case of antibiotics can not be inactivated prepare some of antibiotic in a sterile saline or in a suitable soln immediately filter tho a mum brane filter pore size less than 0.45 cc & 47 mm diameter. Wash the membrane with sterile solvent until free of antibiotic cut it into two halves; one half is inoculated in medium for bacteria and other half in medium for fungi.
Insoluble power suspension and preparations giving precipitate:-
Sub cultures are made between the 23rd and 9th day organism present will grow in fresh medium and turbidity can be observed.
Oily preparation:-Use media to which polysorbute 80 or any other suitable emulsifier is added for inoculation. For ointments the same procedure could be followed or it could be dissolved in sterile is opropylmgristate and filtered tho a membrane filter and tasted same on antibiotics.
Automatic sterility testing c involves detection of contaminant by allowing to contaminants to grow on media containing carbon c14 less elect c14 produced by metabolism of organism can be recorded by rediomdrical vials containing appropriate medium with labeled substrate inoculated c test sample incubate and agitated and shaken under controlled condition the vial cups one then automatically punctured c sterile needles. The labeled CO2 or other gas is then flushed out from the wire to the recorder.
Gas cromatography:- This technique can be used for identifying and quantizing small amts of metabolic produce from the contaminants. Volatile compounds like acitoine, propiaulid or bacteric acid can be detected with in a few hours.
1) Test for extraneous organism is curried out as per the normal test for sterility.
2) Absence of virulent micro bacteria :>. Sample is injected subcutaneously to six healthy guinea pigs and observed for period of 6 week. Non of guinea pig should die c in thin period.
Interpretation of Result:- The inoculated tubes observed or examined periodically during incubation for evidence of growth (turbidity). If no turbidity is observes the preparation passes the test for sterility. If turbidity is observed preserve the container showing both unless it can be demonstrated by any other means that the presence is due to causes unrelated to the preparation. Prefer the retest using same no of samples if no evidence of growth is founder the sample passes the test to sterility. If growth is found isolate and identify the organism. It these organisms are not readily distinguishable form those organisms in containers in 1st test. The preparation fails the test for sterility.
If they are distinguishable second retest is carried out using twice the no of sample. If no growth is observed example passes the test of sterility and if ails if otherwise
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