Formulation, preparation and in vitro - in vivo evaluation of compression-coated tablets for the colonic-specific release of ketoprofen

ABSTRACT The aim of this study was to formulate and prepare compression-coated tablets for colonic release (CR-tablets), and to evaluate the bioavailability of ketoprofen following the administration of a single dose from mini-tablets with immediate release (IR-tablets) compared to CR-tablets. CR-tablets were prepared based on time-controlled hydroxypropylmethylcellulose K100M inner compression-coating and pH-sensitive Eudragit® L 30D-55 outer film-coating. The clinical bioavailability study consisted of two periods, in which two formulations were administered to 6 volunteers, according to a randomized cross-over design. The apparent cumulative absorption amount of ketoprofen was estimated by plasma profile deconvolution. CR-tablets were able to delay ketoprofen's release. Compared to IR-tablets used as reference, for the CR-tablets the maximum plasma concentration (Cmax) was lower (4920.33±1626.71 ng/mL vs. 9549.50±2156.12 ng/mL for IR-tablets) and the time needed to reach Cmax (tmax) was 5.33±1.63 h for CR-tablets vs. 1.33±0.88 h for IR-tablets. In vitro-in vivo comparison of the apparent cumulative absorption amount of ketoprofen showed similar values for the two formulations. Therefore, the obtained pharmacokinetic parameters and the in vitro-in vivo comparison demonstrated the reliability of the developed pharmaceutical system and the fact that it is able to avoid the release of ketoprofen in the first part of the digestive tract.

Efficacy and safety of two pH-dependent-release mesalamine doses in moderately active ulcerative colitis: a multicenter, randomized, double-blind, parallel-group study

BACKGROUND/AIMS: The therapeutic effect of mesalamine is considered to be dose-dependent; however, no consensus has been reached regarding the optimal doses for individual patients. This study aimed to provide new insight for dose optimization using two doses of pH-dependent release mesalamine for induction of remission of moderately active ulcerative colitis (UC). METHODS: In a multicenter, double-blind, randomized study, 110 patients with moderately active UC were assigned to two groups after treatment with a constant dose of mesalamine. Fifty-five patients were treated with a pH-dependent release formulation of 3.6 or 4.8 g/day for 8 weeks. The primary endpoint was a decrease in the UC disease activity index (UCDAI) adjusted by covariates. RESULTS: In the full analysis set (n=110), the mean decrease in UCDAI was 3.1 in the 3.6 g/day group and 3.4 in the 4.8 g/day group (P>0.05). In a subgroup analysis, the effectiveness of the 4.8 g/day dose was greater in particular populations, such as those who had been previously treated with a lower dose of mesalamine and those with more severe disease. The safety was comparable between the two groups. CONCLUSIONS: The results suggest that treatment with pH-dependent release mesalamine at either 3.6 or 4.8 g/day was effective and safe for the induction of remission in patients with moderately active UC. However, the patients receiving mesalamine at 2.4 g/day but in whom the therapeutic effect is not sufficient and having more severe symptoms (UCDAI 9-10), benefit from higher doses of mesalamine compared to others.