Pearl Therapeutics, a Redwood City, Calif.-based developer of inhaled drugs to treat respiratory diseases like COPD and asthma, just landed $8 million in venture debt from Oxford Finance and Silicon Valley Bank to expand its product line.

The company licensed particle-based technology from San Carlos, Calif.-based Nektar Therapeutics to improve inhaled drug targeting and lung distribution, cutting down on negative side effects. So far, it has not disclosed whether its products are in clinical trials or when they might reach the commercial market.

Pearl previously raised $33.5 million over two rounds of funding. Its most recent investment, amounting to $18 million, came in July 2008. Past backers include New Leaf Ventures, 5AM Ventures and Clarus Ventures.