An open-label, randomized, crossover study to evaluate the bioavailability of nanoemulsion versus conventional fat-soluble formulation of cholecalciferol in healthy participants.

BACKGROUND

Nanoemulsion preparations of cholecalciferol available in the market claim to have better bioavailability than the conventional fat-soluble cholecalciferol. However, limited data are available in humans for such preparations. We, therefore, compared the relative bioavailability of two formulations of 60,000 IU cholecalciferol (nanoemulsion oral solution, water-miscible vitamin D3 [test] vs soft gelatin capsules [reference]) in healthy adult participants.

METHODS

In this randomized, open-label, two sequence, single-dose, two-way crossover study (CTRI/2018/05/013839), Indian participants aged 18-45 years received single dose of nanoemulsion and capsule formulations, under fasting conditions. Blood samples collected over 120 h were assessed to determine cholecalciferol concentrations. Pharmacokinetic parameters (area under the concentration-time curve up to 120 h [AUC], maximum observed drug concentration [C], time to reach maximum drug concentration [T], terminal half-life [T], and terminal elimination rate constant [K]) were estimated using baseline corrected data and analyzed using analysis of variance.

RESULTS

Among the 24 eligible participants, the relative bioavailability of nanoemulsion was significantly higher than the capsules by 36% (p = 0.0001) based on AUC. Similarly, C of the nanoemulsion was significantly higher by 43% (p = 0.0001) than that of the capsules. The intra-participant variability for AUC and C were 23.22% and 26.51%, respectively. The T, T, and K were comparable for both the formulations. No adverse effects were noted with either of the two formulations.

CONCLUSIONS

Nanoemulsion oral solution of cholecalciferol showed a greater bioavailability compared with soft gelatin capsules, under fasting conditions, in healthy human participants.