Floating capsules containing alginate-based beads of salbutamol sulfate: In vitro–in vivo evaluations

The present study deals with the development and evaluations of stomach-specific floating capsules containing salbutamol sulfate-loaded oil-entrapped alginate-based beads. Salbutamol sulfate-loaded oil-entrapped beads were prepared and capsulated within hard gelatin capsules (size 1). The effects of HPMC K4M and potato starch weight masses on drug encapsulation efficiency (DEE) of beads and cumulative drug release at 10 h (R10 h) from capsules was analyzed by 32 factorial design. The optimization results indicate increasing of DEE in the oil-entrapped beads and decreasing R10 h from capsules with increment of HPMC K4M and potato starch weight masses. The optimized formulation showed DEE of 70.02 ± 3.16% and R10 h of 56.96 ± 2.92%. These capsules showed floatation over 6 h and sustained drug release over 10 h in gastric pH (1.2). In vivo X-ray imaging study of optimized floating capsules in rabbits showed stomach-specific gastroretention over a prolonged period.