The natural health product company confirmed in a stock market statement that the proposed transaction was approved by shareholders at an AGM yesterday.
Earlier this month, it was agreed that Alliance Pharma would pay up to US$17.5mln for the worldwide rights to Vamousse - with US$13mln coming upfront, followed by US$4.5mln of contingent payments tied to sales milestones.
Tyratech shares were up around 10% on Thursday while Alliance also edged into positive territory.
Alliance chief executive John Dawson said: "The completion of this acquisition provides Alliance a third International star brand with best in class technology.
“There is also real potential for further growth through our substantial global network of distributors."
Following the sale, Tyratech intends to focus on opportunities in the animal health, for control of insects and parasites, where it sees a possible US$6bn market.