Dosage form and formulation effects on the bioavailability of vitamin E, riboflavin, and vitamin B-6 from multivitamin preparations.
The effects of formulation factors and pharmaceutical dosage form on the bioavailability of RRR-alpha-tocopherol (d-alpha-tocopherol), riboflavin, and pyridoxine hydrochloride were studied after administration of two capsule formulations and a tablet to 12 normal humans. Absorption of RRR-alpha-tocopherol was increased from the Aquabiosorb soft elastic gelatin (SEG) capsule formulation compared with the modified standard-SEG capsule and the commercial tablet. There were no significant differences in bioavailability of riboflavin and pyridoxine hydrochloride between the SEG formulation and the tablet albeit a trend toward consistent absorption was seen from the SEG formulation. The modified-SEG formulation exhibited significantly lower bioavailability for these water-soluble vitamins. The enhanced bioavailability of vitamin E and the trend towards faster and more consistent absorption of riboflavin and vitamin B-6 from the SEG formulation may be related to the surfactant vehicle employed and the attendant wetting properties. The results also suggest ethnic differences in vitamin bioavailability.
D000328:Adult; D001682:Biological Availability; D002214:Capsules; D006801:Humans; D008297:Male; D014677:Pharmaceutical Vehicles; D011736:Pyridoxine / Q000097:blood*; D012256:Riboflavin / Q000097:blood*; D013607:Tablets; D014810:Vitamin E / Q000097:blood*; D014815:Vitamins / Q000008:administration & dosage*
D002214:Capsules; D014677:Pharmaceutical Vehicles; D013607:Tablets; D014815:Vitamins; D014810:Vitamin E; D011736:Pyridoxine; D012256:Riboflavin