Injection lipolysis: Combining ingredients yields best fat-reducing results

March 1, 2009

Injection lipolysis may work best when phosphatidylcholine is combined with deoxycholate, an expert says.

Key Points

Phosphatidylcholine, when it is combined with deoxycholate for injection lipolysis, "may lead to reduced swelling and fewer nodules," says Adam Rotunda, M.D., a Newport Beach, Calif., dermatologist.

Italian study

When phosphatidylcholine is included with the other agent commonly used, sodium deoxycholate, the effect was the same, but the inflammation and immune reaction was less.

Patients treated with injection lipolysis often have localized adverse effects including swelling, erythema, and sometimes the development of nodules that may last for months.

The study was conducted because of Dr. Rotunda's own work. A few years ago, he and a group at the University of California, Los Angeles, looked at the effect of phosphatidylcholine and deoxycholate together, and the effect of deoxycholate alone in cell culture and a pigskin model.

The work led to a patent for a deoxycholate-alone formulation, and that patent is now being investigated by a start-up firm, Kythera Biopharmaceuticals, Inc., in Calabasas, Calif. The company has the product in phase 2 trials.

The Italian trial enrolled 40 patients, of whom 37 completed the trial. The investigators injected the thighs of the subjects, using each thigh as a control for the other. One side was injected with the combination, the other with deoxycholate alone.

Results

After four treatments, each spaced eight weeks apart, the results were significant, they say.

Thirty-three of the 37 patients had fat reduction, and there was no statistically significant difference between the two sides. The patients had a mean reduction of about 7 percent from baseline in circumferential thigh measurements (6.46 percent for the combination, 6.77 percent for deoxycholate alone), and an almost 40 percent mean reduction from baseline in ultrasound fat-thickness measurements (36.87 percent and 36.06 percent, respectively).

Side effects

Most patients experienced localized burning and swelling immediately following the procedure. Many also developed erythema and transient nodules.

The nodules were present for a longer period of time in those treated with deoxycholate alone, and there was more swelling. Dr. Salti and colleagues hypothesized that the phosphatidylcholine emulsifies free fat and carries it away.

Dr. Rotunda says this is raising an important question. Presuming that injection lipolysis is found to be effective, there is no reason to complicate treatments by giving two agents when one is effective - unless the second agent really is beneficial.

"We need more data to understand the hypothesis that phosphatidylcholine works by shuttling away the deoxycholate-ablated fat, as suggested by Dr. Salti and colleagues," Dr. Rotunda tells Dermatology Times.

Disclosure: Dr. Rotunda has received consulting fees from Kythera.