Immediate-release tablet formulation of rebamipide and a pharmacokinetic study in healthy human subjects.

OBJECTIVE: To develop an immediate-release tablet preparation containing rebamipide (RBM) and perform the bioavailability assessment in the healthy human subjects. MATERIALS AND METHODS: Raw RBM powder was characterized using differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy (SEM). RBM tablets were manufactured by the wet granulation method, and their dissolution behavior was compared with the reference tablet (Mucosta). A phase I study (n = 47; sequence-randomized, open-label, single-dose, and two-way cross-over design) was designed for oral administration of a test formulation (F4) and Mucosta to healthy human male subjects, and pharmacokinetic parameters including the maximum plasma concentration (Cmax) and area under the curve from 0 to 12 hours (AUC0-12h) were compared. RESULTS: RBM powder had a multimodal size distribution with typical crystallinity, and the needle-like and elongated morphologies of RBM were visualized using SEM. Various tablet formulations (F1 - F6) were successfully manufactured using wet granulation method. F4 formulation was selected based on the dissolution profile most equivalent to that of Mucosta. F4 was stable for 6 months under accelerated and long-term storage conditions. Based on one-way analysis of variance, the AUC0-12h (F(1,92) = 2.40, p = 0.13) and tmax (F(1,92) = 0.04, p = 0.85) were not significantly different; however, the Cmax (F(1,92) = 5.45, p = 0.022) showed significant difference between F4 and reference tablets. CONCLUSION: Despite similar in vitro dissolution profiles, in vivo pharmacokinetic results revealed a partial difference between F4 and reference tablets. Thus, further study on formulation development is still needed.

Optimization of a solidified micelle formulation for enhanced oral bioavailability of atorvastatin calcium using statistical experimental design.

To enhance the oral bioavailability of atorvastatin calcium (ATV), a novel solidified micelle (S-micelle) was developed. Two surfactants, Gelucire 48/16 (G48) and Tween 20 (T20), were employed for micelle formation, and two solid carriers (SC), Florite PS-10 (FLO) and Vivapur 105 (VP105), were selected as solid carriers. The S-micelle was optimized using a Box-Behnken design with three independent variables, including G48:T20 (X1, 1.8:1), SC:G48 + T20 (X2, 0.65:1), and FLO:VP105 (X3, 1.4:0.6), resulting in a droplet size (Y1) of 198.4 nm, dissolution efficiency at 15 min in the pH 1.2 medium (Y2) of 47.6%, Carr's index (Y3) of 16.9, and total quantity (Y4) of 562.5 mg. The optimized S-micelle resulted in good correlation showing percentage prediction values less than 10%. The optimized S-micelle formed a nanosized dispersion in the aqueous phase, with a higher dissolution rate than raw ATV and crushed Lipitor®. The optimized S-micelle improved the relative bioavailability of oral ATV (25 mg equivalent/kg) in rats by approximately 509 and 271% compared to raw ATV and crushed Lipitor®, respectively. In conclusion, the optimized S-micelle possesses great potential for the development of solidified formulations for improved oral absorption of poorly water-soluble drugs.

Synthesis and anticancer activities of new 3-allylthio-6-(mono or disubstituted)aminopyridazines.

A new series of 3-allylthio-6-(mono or disubstituted) aminopyridazines was synthesized by reacting 3-allylthio-6-chloropyridazine with several amines to develop new anticancer agents. These new compounds showed antiproliferative activities against lung cancer (A549), hepatoblastoma (Hep3b), prostate cancer (PC3), colon cancer (SW480) and cervical cancer (HeLa) cells in MTT assays, and could be promising candidates for chemotherapy of carcinomas. Compound 5 (3-allylthio-6-homopiperidinylaminopyridazine) showed higher potencies than 5-FU for inhibiting the growth of these cell lines. This suggests the potential anticancer activity of compound 5.