At a special meeting held to discuss the proposal last week 92.55 per cent of Penwest’s shareholders voting in favour of the merger.
The deal, plans for which were first announced in August, will give Endo full control of the Timerex extended releases (ER) delivery technology which it licenses for its top-selling pain treatment Opana ER.
At the time, Endo said that the key motivation, which is being carried out though its West Acquisition Corp subsidiary, was to allow it to retain more of its earnings from the product ahead of its loss of patent protection in 2013.
Newark-based Endo also indicated that the potential application of the technology to other formulations was another driver for the deal.