Pyrogen detection

A preferred method for the detection of pyrogens is the limulus amebocyte lysate (LAL) test. A test sample is incubated with amebocyte lysate from the blood of the horseshoe crab, Limulus polyphemus. A pyrogenic substance will cause a gel to form. This is a result of the... 

In the flocculated state for all suspensions, immediately after mixing, no transmission of light could be detected through the cuvette used and the sedimentation behaviour was different. Thus, instead of the parameters used for the pyrogenic silica systems we used the following characteristics for the precipitated silica mixtures to describe the flocculation and sedimentation behaviour ... 

Pyrogens may be detected in parenteral preparations (or other substances) by a number of methods. Two such methods are widely employed in the pharmaceutical industry. 

This test is popular because it detects a wide spectrum of pyrogenic substances. However, it is also subject to a number of disadvantages, including ... 

Another issue of relevance is that certain biopharmaceuticals (e.g. cytokines such as 1L-1 and TNF Chapter 9) themselves induce a natural pyrogenic response. This rules out use of the rabbit-based assay for detection of exogenous pyrogens in such products. Such difficulties have led to the increased use of an in vitro assay the Limulus ameobocyte lysate (LAL) test. This is based upon endotoxin-stimulated coagulation of amoebocyte lysate obtained from horseshoe crabs. This test is now the most widely used assay for the detection of endotoxins in biopharmaceutical and other pharmaceutical preparations. 

Its major disadvantage is its selectivity it only detects endotoxin-based pyrogens. In practice, however, endotoxin represents the pyrogen that is by far the most likely to be present in pharmaceutical products. The LAL method is used extensively within the industry. It is used not only to detect endotoxin in finished parenteral preparations, but also in WFI and in biological fluids, such as serum or cerebrospinal fluid. 

At the end of four weeks of continued use, during which 4 liters of eluate were collected, samples were sterile and non-pyrogenic. Isotonicity was confirmed (NaCl = 8.94 .03 mg/ml) and neutrality maintained (pH = 6.27 0.16). No tin was detected in generator eluates by differential pulse polarography above a detection limit of 0.1 lig/ml. The radionuclidic identity of Rb-82 is easily confirmed by verification of its 76 sec half-life or through gamma spectrometry. 

Detection of Pyrogenic Impurities.—The following tests serve mainly to detect the presence of pyroligneous acetic acid ... 

Endotoxin. Endotoxin can be detected using the LAL or rabbit pyrogen assays. 

Commercialization of the Endotoxin Detection Kit - The Route to PyroGene and Pyrosense... 

A microfluorimetric or microcolorimetric assay integrated into the rFC assay has allowed high-throughput screens of LPS in multiple samples. Currently, the rFC is used in an LPS-assay to sensitively and specifically detect LPS (Ding and Ho, 2001). The rFC has been incorporated into the PyroGene kit, which was launched in 2004 (Cambrex Inc., USA). Recently, Lonza Inc. (USA) applied rFC in PyroSense, which has potentials for continuous online monitoring of endotoxin in water and other fluids used for large-scale production of biomedical products. 

Method of Pyrogenic Decomposition. One of the most widely used methods for the detection of chloropicrin in air consists in decomposing it by heat and then testing for chlorine in the products. 

The Flame Test. Another method of detection, also based on the pyrogenic decomposition of chloropicrin, consists in passing the gas mixture to be examined into a gas jet, the flame of which maintains a copper spiral at red heat. ... 

The degradation products of androgenous steroids are a further suspected cause of such febrile episodes, since severe fever could be induced by i.m. injection of aetiocholanolone (3a-hydroxy-5p-H-androstane-17-on) (A. Kappas et af, 1957). In 1958 P. K. Bondy et al. for the first time detected an increase in aetiocholanolone in the plasma of patients with unexplained fever episodes, and thus they coined the term aetiocholanolone fever. Other steroids of the 5p-H configuration also revealed this pyrogenic feature. Aetiocholanolone may be the product of disturbed hepatocellular metabolism. Further observations and examinations have meanwhile been reported. (51, 136)... 

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