VALENCIA, Calif. (AP) — MannKind Corp. said Monday it completed the previously announced buyout of a quantity of bulk insulin and a license to make bulk insulin from Pfizer Inc. for $3 million. The company is using the insulin for its inhaled insulin candidate Afresa, which is now under Food and Drug Administration review. Also, MannKind entered into an agreement to maintain and store the remainder Pfizer’s bulk insulin inventory and bought an option to buy the remaining inventory. Last year, Pfizer started switching its Exubera inhaled insulin patients to MannKind’s experimental product. The companies had been partners until Pfizer pulled Exubera from the market in 2007 after it posted dismal sales. Shares of MannKind fell 46 cents, or 5.4 percent, to $8.05 in morning trading. The stock has traded between $2 and $9.25 over the last 52 weeks. Pfizer shares are unchanged at $15.