Bioavailability Assessment of Vitamin A Self-Nanoemulsified Drug Delivery Systems in Rats: A Comparative Study

Objectives: To assess and compare the bioavailability of three different oral dosage forms of vitamin A in rats. The formulations included vitamin A self-nanoemulsified drug delivery (SNEDD) optimized formulation-filled capsule (F1), vitamin A SNEDD optimized formulation compressed tablet (F2) and vitamin A oily solution-filled capsules without any additives (control, F3). Materials and Methods: Bioavailability was assessed after a single oral dose of the three formulations using three groups of rats, each group comprising 6 rats. Blood samples were collected at baseline and over the next 8 h. Plasma was separated and extracted to obtain the drug, which was measured by HPLC. Statistical data analysis was performed using the Student t test and ANOVA with p 0.05 as the minimal level of significance. Results: From the pharmacokinetic parameters, both F1 and F2 showed improved bioavailability compared to F3. The values of AUC ± SD were 3,080.7 ± 190.2, 2,137.1 ± 130.5 and 1,485.2 ± 80.1 ng·h/ml for F1, F2 and F3, respectively. The Tmax was 1 h in case of F1 and F2 as compared to 1.5 h for F3. The Cmax ± SD was 799.5 ± 48.5, 656.2 ± 64.4 and 425.8 ± 33.1 for F1, F2 and F3, respectively. The increase in AUC, Cmax and Tmax was significant (p 0.05). The bioavailability calculated from the AUC for F1 and F2 relative to F3 was 207.4 and 143.8%, respectively. The bioavailability increased almost twofold and 1.4 times for F1 and F2, respectively. Conclusions: The study showed that the newly developed vitamin A SNEDD formulations increased the rate and extent of drug absorption compared to the oily drug solution. The present investigation demonstrated that vitamin A SNEDD optimized formulations, either as filled capsules or as compressed tablets, were superior to its oily solution with regard to their biopharmaceutical characteristics.