Sublingual tablets containing spray-dried carvedilol-loaded nanocapsules: development of an innovative nanomedicine

The aim of this study was to propose the use of spray-dried mucoadhesive carvedilol-loaded nanocapsules in the formulation of sublingual tablets. There is no previous report describing the preparation of tablets containing spray-dried nanocapsules or tablets containing nanocapsules, neither prepared by direct compression nor for sublingual administration. Tablets of 6 mm of diameter and 2.7 ± 0.2 mm of height were obtained with a mean weight of 44 ± 4 mg, carvedilol content of 0.164 ± 0.017 mg, and a disintegration time less than 25 min. They were produced using a force of 4.7 ± 1.6 kgf. The release profile of carvedilol from the tablets was evaluated using the dialysis bag method. In parallel, the release of nanocapsules from the tablet structure into the release medium was evaluated using dynamic light scattering. Nanocapsules that were released from the tablets into the release medium exhibited similar particle size distributions after recovery as in their original liquid suspension, without losing their original ability to control drug release. Therefore, sublingual tablets may be produced from spray-dried drug-loaded nanocapsules using a direct compression technique, providing a useful pharmaceutical approach for drugs that undergo first pass metabolism, such as carvedilol.