Abstract: A method for treating peripheral orthostatic hypotension which comprises administering DL- or L-threo-3,4-dihydroxyphenylserine or a pharmaceutically acceptable acid addition salt thereof to a subject suffering from the disease. The composition may be administered either orally or parenterally.

Abstract: A process for manufacturing a highly concentrated sulfate solution or slurry which comprises neutralizing a sulfuric ester of higher alcohol or its ethoxylate with an aqueous caustic alkali solution, thereby preparing a crude neutralization product containing the sulfate in the range of from 45 wt. % to 55 wt. % and the caustic alkali in the range of from 1.5 wt. % to 3.5 wt. % and having a viscosity less than 50 poise; and commingling the resulting crude neutralization product with the sulfuric ester in the range of from 30 parts by weight to 100 parts by weight per 100 parts by weight of the crude neutralization product and a highly concentrated caustic alkali solution capable of sufficiently neutralizing the sulfuric ester, thereby reducing the quantity of sulfate contained in the resulting mixture in the range of from 60 wt. % to 75 wt. % and the quantity of caustic alkali contained therein less than 0.5 wt. % of the quantity of sulfate.

Abstract: Disclosed is a process for producing a clear aqueous solution of the magnesium salt of an olefin sulfonic acid by (i) sulfonating an olefin with an gaseous sulfur trioxide, (ii) neutralizing the resulting sulfonated olefin with an inorganic alkali consisting of magnesium hydroxide and/or oxide and an organic amine selected from water-soluble alkanol amines in specified amounts and, then, (iii) heating the neutralized mixture at a pH of from 6.0 to 8.0. Thus, a clear aqueous solution of the magnesium salt of an olefin sulfonic acid having no bad odor and no color deterioration can be obtained.