Chitosan nanoparticles making their way to clinical practice: A feasibility study on their topical use for acne treatment

Chitosan Nanocarrier Entrapping Hydrophilic Drugs as Advanced Polymeric System for Dual Pharmaceutical and Cosmeceutical Application: A Comprehensive Analysis Using Box-Behnken Design

“…The folding, referred to as loop conformation of the CS chain, also resulted in fewer amino groups being exposed to the TPP anions, lower crosslinking, and eventually the formation of CS-TPP nanoparticles with larger PS. These findings are in agreement with Abd-Allah et al [23]. The effect of the CS solution pH and CS concentration on PS at a CS: TPP mass ratio of 4:1 is demonstrated in the 3D surface plot in Figure 2B, showing that the effect of pH on PS had a much higher impact upon the formulation using a higher concentration of CS.…”

“…This rapid dispersion leads to the formation of small compact nanoparticles. However, upon increasing CS concentration, the molecules become entangled in such a way that it hinders TPP anions dispersion within CS molecules, thus inefficient crosslinking occurs, and hence larger particles are formed [23,54]. Moreover, at a low CS: TPP mass ratio (2:1), the presence of excess TPP anions above equilibrium leads to interaction with the amino groups in CS and the formation of enlarged particles with lower surface charge.…”

“…Most importantly, CS exhibits permeability enhancing properties due to its cationic nature which enhances skin penetration through interacting with the oppositely charged SC, loosening the tight junction, thus enhancing penetration to subcutaneous adipocytes [20,21]. CS nanoparticles are commonly assembled via ionic crosslinking between positive amino groups present in the CS chains with an oppositely charged agent such as sodium tripolyphosphate (TPP)-a multivalent non-toxic anion (TPP) [22][23][24][25]. Due to the aforementioned advantages, it is used as a carrier for a wide array of drugs including herbal extracts [26,27], antimicrobial agents [28], antiviral drugs [29], and anticancer agents [30].…”

“…The factors (independent variables) employed were (A) CS concentration, (B) pH of CS solution, and (C) CS: TPP mass ratio. Low, medium, and high levels of each individual factor presented as −1, 0, and +1, respectively, with their actual values are shown in Table 1 The independent variables range was selected according to previously published literature [22,23,34,35]. Three distinctive zones: clear solution, opalescent suspension, and aggregates, were observed when TPP was added to different concentration of CS.…”

“…Opalescent suspension indicated presence of very small particles, achieved at a final CS concentration between 0.1 and 0.3%, and TPP concentration between 0.02 and 0.1% [22]. The effect of different pH values (from pH of 3 up to 6) of CS solution on PS, PDI, and ZP have been previously studied [23,34,35]. For this reason, the effect of pH within the pre-selected range was used in the current model.…”