South Africa's generic drug giant Aspen has hit the acquisition trail again, this time snapping up a selection of drugs and a manufacturing plant from MSD for around $1 billion.

Under the deal, Aspen has bought itself MSD's (Merck in the US and Canada) active pharmaceutical ingredient (API) manufacturing business in the Netherlands and its satellite facility and sales office in the US.

Also, the firms reached an agreement on an option to acquire a portfolio of 11 branded finished dose form molecules from Merck, covering a diverse range of therapeutic areas.

The main brands being acquired are: the hormone replacement therapies Ovestin, Sustanon and Metrigen; the blood thinner Orgaran; corticosteroids Decadron, Oradexon, Metricorten and Meticortelone; the anabolic steroid Deca Durabolin; Thyrax and Strumazol for hyperthyroidism; the oral contraceptives Gracial and Novial; and the vitamin B complex Benutrex.

The products generated revenue of $248 million in MSD's financial year ended December 31, 2012, more than half of which came from Latin America and Asia Pacific, in which Aspen is keen to gain a stronger foothold (alongside Europe).

According to Aspen, the move will complement its existing portfolio and will provide "critical mass" to its offering in a number of markets.

Just last week the firm announced plans to buy global rights (except China, Pakistan and India) to GlaxoSmithKline's thrombosis drugs Arixtra and Fraxiparine/Fraxodi.