The IAAF said that 400 metres runner Kseniya Aksyonova, javelin thrower Vera Rebrik and 400 metres hurdler Vera Rudakova had meet the "exceptional eligibility criteria" required to be able to compete as neutrals.
They will join 12 others who were previously cleared after satisfying the IAAF's doping review board that they have been training in an environment that passes the necessary anti-doping requirements.
Aksyonova is a former European champion in the 400 metres relay and silver medallist in the individual event. Rebrik is also a former European champion and Rudakova has won several golds in junior world and European championship events.
Their participation is still subject to IAAF formalities and acceptance by meeting organisers.
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The Russian national athletics federation (RUSAF) remains suspended as a result of widespread and systematic doping, meaning that the majority of Russian athletes will miss the world championships in London in August.
The IAAF said a further 27 applications are still being considered.
“I’m grateful to the members of the Doping Review Board for the dedication and diligence they are giving to this on-going review process," said IAAF president Sebastian Coe.
"The importance of this huge task should not be underestimated. There can be no time constraints or deadlines when the protection of clean athletes everywhere is at stake.”
Coe said last month he was disappointed by the lack of progress being made by Russia in cleaning up its anti-doping regime and made it clear that the ban on the country's athletics federation would continue indefinitely.
(Writing by Brian Homewood, editing by Pritha Sarkar)
