B.D.H. Products

Abstract

WE have received from the British Drug Houses, Ltd., London, N.1., copies of their catalogues of fine chemical products and micro-analytical reagents and organic reagents for ‘spot’ tests. The standards of purity adopted for chemical products are described in the B.D.H. book of A. R. Standards and those for pharmaceutical preparations in the book of P.P.P. (pure for pharmaceutical purposes) Standards. In the case of the latter, other considerations as well as purity must be taken into account, for example, ease of weighing for dispensing, and ready solubility with the formation of a clear bright solution. Low limits for lead and arsenic are defined, being in the case of most substances only a few parts (1 to 5) in a million. Other metallic impurities may not be physiologically harmful, but may cause precipitation, coloration, or some other reaction and so create difficulties in dispensing: their limits must therefore be fixed as well. The catalogues of fine chemicals run to nearly 150 pages and include lists of standard reagents, indicators, microscopic stains, and dyes. The same firm has also issued recently revised editions of booklets describing their vitamin A and vitamin D preparations, avoleum, radiostol, radiostoleum, and radio-malt. Advance in our knowledge in the vitamin field has been so rapid that frequent revision of brief summaries of this work is required. The activities of the products are controlled by physiological tests and standardised in terms of the international standards wherever such standards are available.