A composition for treating respiratory diseases and strengthening the
immune system is provided including a synergic mixture of a) oil extracted from seeds of the
plant Nigella sativa diluted in
propylene glycol with b) an alcoholic extract with
ethanol obtained from aerial parts of the
plant Asclepias curassavica. The composition is prepared by (a) extracting seed oil from the
Nigella sativa
plant, adding the extracted seed oil to
propylene glycol; (b) macerating aerial parts of Asclepias curassavica plants in
ethanol with a
resting time if subjected to a water bath or another
resting time without the water bath, straining and filtering; c) mixing a volume of the alcoholic extract of Asclepias curassavica with a volume of oil extracted from the seeds of the
Nigella sativa plant diluted in
propylene glycol; d) shaking and letting it rest.