"The results indicate that the oral absorption and bioavailability of CoQ10 could be significantly enhanced by the complexation with gamma-cyclodextrin, suggesting the potential use of gamma-cyclodextrin for an oral capsule formulation containing CoQ10 powder," wrote lead author Keiji Terao in the journal Nutrition Research (Vol. 26, pp. 503-508).
There is an ever-growing body of scientific data that shows substantial health benefits of CoQ10 supplementation for people suffering from angina, heart attack and hypertension. Clinical trials have also reported benefits for cardiomyopathy and congestive heart failure.
However, the formulation of the CoQ10 is known to play a key role in its bioavailability. Since the coenzyme is lipophilic (fat-loving) its absorption is enhanced in the presence of lipids. Therefore, when taken as a supplement apart from meals, the absorption of some formulations is lower.
Trials with CoQ10 supplements in powder and oil-suspension forms are reported to result in small or negligible responses in plasma CoQ10 concentrations.
"In fact, the oral bioavailability of currently available CoQ10 formulations including a nanoparticle and a solid dispersion is very low, although reports have differed widely," said Terao and co-authors. "Thus, there is a need to develop improved formulations for the oral delivery of CoQ10."
CycloChem and Wacker-Chemie are both gamma-cyclodextrin producers, with Wacker claiming to be the world's leading producer of cyclodextrin products, marketed under the Cavamax brand name.
The new research compared bioavailability of a CoQ10-gamma-CD complex (Cavamax W8/CoQ10, Wacker-Chemie) with CoQ10- microcrystalline cellulose (MCC) formulation. The CoQ10 was purchased from Mitsubishi Gas Chemical Company.
"Several commercial CoQ10 formulations in the market have been developed with MCC as the standard excipient," explained the researchers.
The scientists recruited 22 healthy volunteers (12 men, age 20-50, free of medication) and gave them a 150 mg capsule containing 30 mg CoQ10 under fasting conditions. The study was of an open-label, crossover design, with a two-week washout period in the middle before the volunteers were given the other formulation.
Six to eight hours after taking the capsules, CoQ10 levels in the blood of the participants, measured by high-performance liquid chromatography (HPLC), were found to have risen by an average of 48 per cent with the CoQ10-gamma-CD capsule, while the CoQ10-MCC capsule was associated with an average plasma CoQ10 rise of 14 per cent.
"These enhancing effects of the complexation of CoQ10 with gamma-CD on oral bioavailability of CoQ10 in healthy volunteers could be attributed to the solubilising effect and the fast dissolution rate," said the researchers.
"These results indicate that the oral absorption and bioavailability of CoQ10 in healthy adult volunteers could be significantly enhanced by complexation with gamma-CD, suggesting the potential use of gamma-CD as formulation aid for orally administered CoQ10," they concluded.
Work on formulation and increasing bioavailability for the ingredient is not new, with many companies offering solutions to the problem. For dietary supplements, BASF unveiled two new grades, SoluQ10 5% and Coenzyme Q10 10% DC, at the end of April. The former, it said, is a solubilizate of CoQ10 said to have excellent liquid dosing properties for use in softgels, while the latter is a 10% DC stable, fast-acting powder for direct compression into tablets.
The company says this means manufacturers no longer need go through the wet granulation and compaction processes that are necessary when working with conventional powders.
US distributor Blue California is also offering a new line of water-soluble coenzyme Q10 ingredients said to be more bioavailable than standard forms of the co-enzyme. CoQ10-WS is said to be a free-flowing, water-soluble powder, available in both 10 and 20 percent concentrations. It is suitable for use in beverages, tablets and capsules.
DSM meanwhile has its All-Q brand that uses a starch-based powder as a carrier for 10 per cent purity CoQ10, making the normally fat-soluble ingredient stable for formulation in water-based beverages, dairy products or energy drinks, the company said.
Others have set their sights on similar functionality. For instance, AquaNova has applied its nanotech system known as NovaSol to CoQ10, whereby the active substance is contained within product micelles. This is said to make it more bioavailable, and lend the active ingredient fat and water solubility, which means it can be added to clear liquids without affecting the clarity.