Donev bought the shares on the floor of the Bulgarian Stock Exchange, the drug manufacturer said in a stock exchange filing.
Donev has directly acquired a total of 260,255 shares in Sopharma, or 0.19% interest, since the start of December.
In a separate filing on Friday, Sopharma said that Donev Investments Holding acquired 350 shares in the company at a price of 2.98 levs apiece. Donev Investments Holding is controlled by Ognyan Donev.
At the end of September, Donev Investments Holding was Sopharma's largest shareholders with a 25.93% stake, while Donev held a stake of under 5% directly.
As at 15:30 CET on Friday, Sopharma shares traded 1.33% higher at 3.04 levs on the Bulgarian Stock Exchange.
(1 euro = 1.95583 levs)