Development of novel gastroretentive salbutamol sulfate-loaded sodium alginate-pectin bubble beads prepared by co-axial needle air-injection method and in vivo clinical evaluation by ultrasound studies.

In the present study, the salbutamol sulfate-loaded sodium alginate-pectin (SS-loaded SA-PEC) bubble beads have been optimized and evaluated for drug loading, in vitro drug release, in vivo floating behavior in the stomach, etc. Nine batches (F1-F9) of bubble beads with different SA and PEC contents were prepared by novel co-axial needle air-injection method and related to their percent drug loading efficiency (%DLE) and percent drug release at 4 h (%R4h ) as response factors. The multivariate analysis has shown the effect of SA/PEC ratio, total polymer content, as well as their interaction on %DLE and %R4h . In the quantitative modeling, the satisfactory adjustment of the linear models (along with interaction terms) with the experimental data for both %DLE and %R4h has confirmed the findings of the multivariate analysis. The optimized SS-loaded SA-PEC bubble beads based on 2D (contours), 3D, desirability, and overlay plots has exhibited %DLE of 87.35 ± 2.48% (n = 3 and error = 2.94%) and %R4h of 85.79 ± 2.98% (n = 3 and error = 0.25%). The in vitro drug release studies have shown almost complete (≥85%) SS release from all the batches within 4-6 h in simulated gastric fluid (SGF) pH 1.2. The in vivo clinical findings by ultrasound studies have shown excellent floatation (>6 h) behavior of bubble beads in the upper gastrointestinal tract (GIT) and efficient stomach-specific gastroretention.