Nicotine-loaded sodium alginate–magnesium aluminum silicate (SA–MAS) films: Importance of SA–MAS ratio

Abstract

The objective of this work was to investigate the influence of the sodium alginate–magnesium aluminum silicate (SA–MAS) ratio on film properties for nicotine (NCT) mucosal delivery. NCT-loaded SA–MAS films with varying SA–MAS ratios were prepared at acidic and basic pH, which represent the protonated and neutral species of NCT, respectively. The film characteristics, such as NCT content, muco-adhesive properties, NCT release and skin and mucosal membranes NCT permeation were examined. The result showed that increasing the MAS ratio in the films caused an increase in NCT retention and a decrease in the NCT release rate. The NCT release mechanism of the NCT-loaded SA–MAS films prepared at acidic and basic pH was an anomalous transport and a swelling controlled mechanism, respectively, and was primarily impacted by the SA content in the films. The NCT permeation rate across the mucosal membrane decreased with increasing MAS ratio of the films. The mucosal drug permeation kinetics suggested a matrix diffusion controlled mechanism, whereas skin penetration acted as a rate-limiting step of drug permeation. Film preparation pH also affected NCT release and permeation due to the unique charge characteristics of the various NCT species formed. Furthermore, films with a high MAS ratio could adhere to the mucosal membrane. These findings suggest the SA–MAS ratio remarkably influences the characteristics of the NCT-loaded SA–MAS films, and that these films demonstrate a promising mucosal drug delivery system.