Drug agent delivers MacroChem from obscurity. (MacroChem signs deal giving Upjohn Co. licensing rights to SEPA)

A tiny Bay State biotech company has injected some life into its bottom line with a drug-delivery agent that helps minoxidil, the hair-growth drug, soak deeper into balding scalps.

Billerica-based MacroChem signed a multimillion dollar deal three weeks ago that gives the Upjohn Co. exclusive worldwide licensing rights to the agent, SEPA, with Rogaine, a brand name for minoxidil. Upjohn will pay license fees and royalties, and take SEPA through the human testing phase of its development. MacroChem (OTC: MCHM) hopes the agreement will pave the way for future applications of SEPA in painkillers, anti-inflammatory drugs, cosmetics, over-the-counter drugs and pesticides.

"We're talking markets of billions of dollars," gushed Dr. Carlos M. Samour, chairman and scientific director of MacroChem.

SEPA works by carrying a drug or chemical through the …