Development and pharmacokinetic evaluation of Neusilin® US2-based S-SNEDDS tablets for bosentan: Fasted and fed states bioavailability, IVIS® real-time biodistribution, and ex-vivo imaging.

The study reported here aimed to develop and optimize the S-SNEDDS tablet of bosentan (BOS) and to investigate its pharmacokinetic and biodistribution properties. The BOS-loaded SNEDDS have been developed and characterized in a previous study. The BOS-loaded SNEDDS formulation was converted to S-SNEDDS using Neusilin® US2. The S-SNEDDS tablets were obtained using the direct compression technique, and in vitro dissolution, in vitro lipolysis, and ex-vivo permeability studies of the tablets were performed. The S-SNEDDS tablet and reference tablet (Tracleer®) were administered to male Wistar rats at 50 mg/kg dose by oral gavage in fasted and fed state conditions. The biodistribution of the S-SNEDDS tablet was investigated in Balb/c mice using fluorescent dye. The tablets were dispersed in distilled water before administration to animals. The relationship between in vitro dissolution data and in vivo plasma concentration was examined. The S-SNEDDS tablets showed 2.47, 7.49, 3.70, and 4.39 increases in the percentages of cumulative dissolution in FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2, respectively, when compared to the reference, and increased the Cmax and AUC 2.65 and 1.28-fold and 4.73 and 2.37-fold in fasted and fed states, respectively, when compared to the reference. S-SNEDDS tablets also significantly reduced interindividual variability in both fasted and fed states (p < 0.05). The XenoLight™ DiR and VivoTag® 680XL labeled S-SNEDDS tablet formulation increased the real-time biodistribution in the body by factors of 2.4 and 3.4 and organ uptake and total emission increased by factors of 2.8 and 3.1, respectively. The IVIVR has been successfully established for S-SNEDDS tablets (R2 > 0.9). The present study confirms the potential of the S-SNEDDS tablet to enhance the in vitro and in vivo performance of BOS.

Comparison of tablet splitting techniques for dosing accuracy of nebivolol tablets: Hand splitting versus tablet cutter and knife.

Tablet splitting is a common practice in clinical settings to lower doses, facilitate swallowing or save costs. Splitting devices can be used when hand splitting is difficult or painful. However, data on the accuracy of tablet splitting are limited and it presents a number of patient or formulation-related problems. Thirty nebivolol IR tablets on the Turkish market were split by hand, a tablet cutter (Rabir®) or a knife, and tested for weight variation, loss of mass, disintegration, and friability. The accuracy of split tablets was in the range of 75.4-121, 82.4-115, and 86.9-115% when split by hand, the cutter, and knife, respectively. No significant difference in accuracy was determined between the left and right sides split by the cutter (p = 0.222). The differences were significant for hand and knife splittings (p < 0.005). The precision was 9.02, 7.87, and 6.11% (CV%) for hand, tablet cutter, and knife, respectively. Only hand splitting failed to comply with the subdivision test of European Pharmacopoeia. The split portions met USP standards for friability (<1%). Splitting decreased the disintegration time (4.5 vs. 2.2 min). Overall, the accuracy of the tablet cutter was more favorable than hand splitting and knife. The study demonstrated that the splitting technique may result in inaccurate dosing and significant drug fluctuations for nebivolol tablets.