Valencia biotech MannKind Corp. on Tuesday announced that it has received a $1 million milestone payment from Receptor Life Sciences Inc. of Seattle for completing initial formulation studies.

The payment is part of a licensing agreement between the two companies to develop multiple inhaled therapeutic products for the treatment of conditions like chronic pain and inflammatory disorders.

“The results of these studies have further validated the versatility of our formulation technology,” MannKind Chief Executive Matthew Pfeffer said in a statement. “We are pleased with the progress to date and look forward to the next phase of product development in our collaboration with RLS.”

As part of the contract, MannKind is responsible for initial studies, while Receptor will oversee manufacturing and commercialization for the future drugs. However, the deal does not include MannKind’s only approved product in its portfolio – Afrezza – an inhalable insulin used to control blood sugar levels in diabetics that has been struggling in sales.

MannKind shares closed down 1 cent, or less than a percent, to 63 cents on the Nasdaq.