The assay of preparations containing pilocarpine and the characters of pilocarpine nitrate and hydrochloride / by H.D. Jowett.

  • Jowett, H. A. D. (Hooper Albert Dickinson)
Date:
[1899?]
Catalogue details

Licence: Public Domain Mark

Credit: The assay of preparations containing pilocarpine and the characters of pilocarpine nitrate and hydrochloride / by H.D. Jowett. Source: Wellcome Collection.

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    a salt described as “ pure pilocarpine nitrate ” molted at 141-7°, and when recrystallised from alcohol in different fractions gave no con¬ siderable alteration in the melting point. They have also examined samples of pilocarpine hydrochloride on the market and found in¬ dications of the presence of more than one alkaloid. They remark that a possible explanation given, viz., that the impurity present was jaborine, requires more definite proof. Petit and Polonowsky* have examined the salts of pilocarpine and give the following constants : — /Prisms soluble in 7 parts of water , at 18°, in 146 parts alcohol (95 p.c) 1 llocarpme nitrate .j at 18o. Melting point 177°-178° l [a] D = + 82-2°. (Anhydrous prisms, soluble in 0*4 Pilocarpine hydrochloride parts of water, in 10 parts alcohol. ( Melting point 200°. [a]D = + 91°. They also state that commercial specimens examined contained an impurity, stated to be pilocarpidinc, to as large an extent as 50 per cent. These results, however, relate to chemically pure products, and it is not always advisable to insist on this degree of purity for chemicals required for medicinal use, owing to the extra expense incurred not being commensurate with the corresponding thera¬ peutic advantage. These results, therefore, required confirmation and also investiga¬ tion as to the ease with which such impurities are removed, and the effect of small amounts of such impurity on the physical constants of the pure salt. The question has also been raised as to the identity of the alkaloid pilocarpine, when obtained from different species of jaborandi leaves, the results of Paul and Cownley being insufficient to answer this question. In the present communication I give a method for determining the amount of pilocarpine in the total alkaloid, then proof of the identity of pilocarpine from different sources, and finally the characters and tests for pilocarpine nitrate and hydrochloride. Assay of Preparations containing Pilocarpine. Several methods are available for extracting the total alkaloid from jaborandi or its preparations, and any of these may be used to obtain the mixture of amorphous bases. The varnish obtained is dissolved in a small quantity of a saturated alcoholic solution of pilocarpine nitrate, and to this solution is f Juurn. de Pharmacie [6J, 5, 370, 430, 475, and [6], 6, 8.