Chlorides European Pharmacopoeia 244

The test ensures that the substance to be examined has a total content of chloride (Cl-), which is below the limit defined in the individual monograph. The test is referenced in several hundred monographs and this makes it one of the most highly referenced general tests. Chloride, obviously, is nontoxic and chemically inert and therefore harmless both from a safety viewpoint and with respect to the chemical stability of the substance to be examined. So the reason for limiting its presence is,...

Precipitation in limit tests

The precipitation of an insoluble substance from a solvent is a complicated process and great effort has been put into understanding the nature of the steps involved. These steps are, regardless of the nature of the precipitate in question, nucleation and crystal growths. The response of precipitate formations to different sets of conditions, on the other hand, depends strongly on the type of substance being precipitated. It is therefore relevant to go through some of the principles of...

Alkaloids European Pharmacopoeia 231

The test identifies the substance to be examined as an alkaloid. Alkaloids are a very large class of substances with a somewhat vague definition. Traditionally alkaloids have been identified with the use of four analytical reagents Mayer's reagent, a potassiomercuric iodide solution Wagner's reagent, a solution of iodine in potassium iodide Hager's reagent, a picric acid solution Dragendorff's reagent, a potassium bismuth iodide solution One definition of an alkaloid is that it is a substance...

Ch3 ch c

Technically it can be prepared by fermentation of various carbohydrates, among others glucose. It has one carboxylic acid group with a pKa value of 3.8. It is soluble in water, alcohol, and furfurol but less soluble in ether. It is practically insoluble in chloroform, petroleum spirits, and carbon disulphide. The acid form is a crystalline powder that has a boiling point of 16.8 C, and the salts are likewise usually crystalline substances. A color reaction...

Alkaline impurities in fatty oils European Pharmacopoeia 2419

This test ensures that the fatty oil to be examined has a content of alkaline impurities, which is below the limit defined in the individual monograph. The need for controlling alkaline residues in fatty oils comes from one of the procedures used to purify crude vegetable oil into pharmaceutical grade oil. The fatty oils covered by the purpose of the test are triglycerides of miscellaneous fatty acids. Triglycerides, called fixed fats or fixed oils, are used for the storage of energy in both...

Heavy metals European Pharmacopoeia 248

The test ensures that the substance to be examined has a content of heavy metals, which is below the limit defined in the individual monograph. Heavy metals are in the test defined by the selectivity of the methods to include lead, copper, silver, mercury, cadmium, bismuth, ruthenium, gold, platinum, palladium, vanadium, arsenic, antimony, tin, and molybdenum. The contents of heavy metals in active pharmaceutical ingredients and excipients are tested for two reasons due to the toxicity of the...

Color reactions in limit tests

Visually comparing the color intensity of a sample with a standard of known concentration, after reacting both with a selective reagent, is a very old analytical principle. In the second half of the nineteenth century, it was discovered that several (colorless) alkaloids and other pharmaceutical substances produced characteristic colors when treated with certain inorganic reagents. These reactions made possible semiquantitative determinations of the substances, but there was most often no...

Ammonia Release Pharmacopea Method

This method first described by Nash in 1952 has the advantage over many of the other colorimetric formaldehyde methods in that the reaction takes place under relatively mild reaction conditions. One disadvantage, however, is that a reaction is gained not only with free formaldehyde but to some extent also with bound and, although to a limited extent, polymeric formaldehyde. Figure 6.15.1 3,5-diacetyl-1,4-dihydrolutidine. For vaccines for human use, a 1 in 10 dilution of the vaccine to be...

Xanthines European Pharmacopoeia 231

The test identifies the substance to be examined as a member of the group of compounds called the xanthines, and at the present about 10 monograph reference xanthines. Xanthines are compounds that historically have been extracted from plant material containing the core element of xanthine (Figure 3.34.1). Biochemically they are derived from the nucleotide purine (Figure 3.34.2). The different xanthines have various alkyl groups attached to the three nitrogen atoms not participating in the...

Silver European Pharmacopoeia 231

The test identifies the substance to be examined as a salt of silver (Ag+). At the present silver is referenced in only one monograph, silver nitrate. This salt is sold in sticks, called Lapis or Lapis lunaris, and is used for the treatment of warts. Silver can exist both as silver(I) and silver(II), but since the latter is less stable, silver(I) dominates. It is a noble metal meaning that it is most stable in oxidation state 0, its metallic form. So, contrary to most metals, it does not have...

Method b

Test solution (a) in 200 dilution of the vaccine to be examined with R is prepared as described in the pharmacopoea. Solutions containing 0.25 g l, 0.50 g l, 1.00 g l, and 2.00 g l of CH2O by dilution of formaldehyde solution R with R are prepared. To 0.5 ml of the test solution and of each of the reference solutions in test tubes, 5.0 ml of a freshly prepared 0.5 g l solution of methylbenzoethiazolone hydrazone hydrochloride R is added. Tubes are closed, shaken, and allowed to stand for 60...

Free formaldehyde European Pharmacopoeia 2418

The test ensures that the substance to be examined has a total content of formaldehyde (H2CO), which is below the limit defined in the individual monograph. The monograph is named free formaldehyde to exclude its use on formaldehyde groups chemically bound to the substance to be examined. The test is referenced in about 30 monographs all describing vaccines, all of them referencing method (a) and nearly all of them having a free formaldehyde limit of 0.2 g l. Vaccines are inactivated virus...

Precipitate appearance

Precipitates have often been placed in one of three different categories based on their macroscopic appearance. A precipitate can be colloidal, crystalline, or curdy gelatinous. The kind of precipitate given by a specific salt has no correlation to its degree of insolubility but is determined by the particle size distribution of the precipitate, and its affinity toward the water molecules and ions of the surrounding solution. Identification tests are most often designed to give fast results. In...

Calcium European Pharmacopoeia 231

The test identifies the substance examined as a salt of calcium, Ca2 . Reference to calcium is made in about 30 monographs. Owing to the tendency of calcium to form insoluble salts, it is not a common salt of choice for active pharmaceutical ingredients, so the majority of the monographs are for inactive excipients. Among the exceptions are the calcium salts of several amino acids. Being an alkaline earth metal, calcium is found only in the valance two form. Its hydroxide salt is relatively...

Bromides European Pharmacopoeia 231

The test identifies the substance to be examined as a salt of bromide Br- or a substance containing chemically bound bromine that can be released as bromide upon treatment. Reference to bromides is made in about 20 monographs. Test a is dictated in the majority of the monographs, and test b is in only one case dictated alone. Most of the monographs describe bromide salts, ranging from simple inorganic salt to hydrobromides of complex nitrogen bases, and the rest describe organic substances...