Abstract: An aqueous emulsion for use in veterinary medicine which contains beta carotene and can be administered parenterally from a sterile multi-dose container contains acetylcysteine in an amount of between 1 and 8 wt.-% as a substance which stabilizes the emulsion and protects preservatives and beta carotene from being decomposed. The beta carotene-containing emulsion can additionally contain at least one antioxidant and at least one preservative. As the antioxidant, ascorbyl palmitate or alpha-tocopherol can be added. The emulsion can further contain a solubilizer, for example isopropyl myristate or Solutol® HS 15.

Abstract: A method for the production of indolyl lactones of the formula ##STR1## wherein R.sub.1 is hydrogen, halogen, or an alkoxy group having 1 to 4 C atoms and R.sub.3 is hydrogen, characterized in the manner that one reacts a 2-hydroxymethylindole of the formula ##STR2## wherein R.sub.1 has the above named meaning and R.sub.2 is an alkanoyl group or a phenyl alkanoyl group, with an .alpha.-diazoester of the formula ##STR3## wherein R.sub.3 has the above named meaning and R.sub.4 is an alkyl group having 1 to 4 C atoms and a, benzyl group, to a 3-indolyl acetic acid ester of the formula ##STR4## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the above named meanings, saponifies the thus obtained 3-indolyl acetic acid ester of the formula (IV) to the 3-indolyl acetic acid of the formula ##STR5## wherein R.sub.1 and R.sub.3 have the above named meaning, and the latter is dehydrated to indolyl lactone with the formula (I).

Abstract: The process is directed to the production of 1-acyl-2-methyl-indolyl-3-alkanoic acids having the general formula ##STR1## wherein R.sub.1 represents hydrogen, halogen, an alkoxy group or an aryloxy group, n is 1, 2 or 3, and R.sub.2 represents an aromatic group. A lactone having the general formula ##STR2## wherein R.sub.1 and n have the meanings stated above, is acylated by being reacted in a polar solvent in the presence of sodium hydride with an acid derivative having the general formula ##STR3## wherein R.sub.2 has the meaning stated above and X represents a halogen, to form a compound having a lactone ring and having the general formula ##STR4## wherein R.sub.1, R.sub.2, and n have the meanings stated above. The last-mentioned compound is hydrogenolyzed in the presence of a hydrogenation catalyst to open the lactone ring.