Cost Function Analysis Applied to Different Kinetic Release Models of Arrabidaea chica Verlot Extract from Chitosan/Alginate Membranes

Abstract

This work focuses on the mathematical analysis of the controlled release of a standardized extract of A. chica from chitosan/alginate (C/A) membranes, which can be used for the treatment of skin lesions. Four different types of C/A membranes were tested: a dense membrane (CA), a dense and flexible membrane (CAS), a porous membrane (CAP) and a porous and flexible membrane (CAPS). The Arrabidae chica extract release profiles were obtained experimentally in vitro using PBS at 37 °C and pH 7. Experimental data of release kinetics were analyzed using five classical models from the literature: Zero Order, First Order, Higuchi, Korsmeyer–Peppas and Weibull functions. Results for the Korsmeyer–Peppas model showed that the release of A. chica extract from four membrane formulations was by a diffusion through a partially swollen matrix and through a water filled network mesh; however, the Weibull model suggested that non-porous membranes (CA and CAS) had fractal geometry and that porous membranes (CAP and CAPS) have highly disorganized structures. Nevertheless, by applying an explicit optimization method that employs a cost function to determine the model parameters that best fit to experimental data, the results indicated that the Weibull model showed the best simulation for the release profiles from the four membranes: CA, CAS and CAP presented Fickian diffusion through a polymeric matrix of fractal geometry, and only the CAPS membrane showed a highly disordered matrix. The use of this cost function optimization had the significant advantage of higher fitting sensitivity.

Evaluation of Physically and/or Chemically Modified Chitosan Hydrogels for Proficient Release of Insoluble Nystatin in Simulated Fluids

“…NYSm concentrations in PBS solutions were determined, and the release efficiency of the drug was assessed as a function of time. The experimental data were further processed by mathematically fitting with the PFO model, which describes a process dependent on concentrations (Equation (7)) [ 52 ] and the Fick’s Law/K–P semi-empirical equation (Equation (8)), in order to establish the type of NYSm release mechanism (Fickian or non-Fickian diffusion) and the stability behavior of the systems [ 53 ]: S r (%) = S 0 (1 − exp (−k r × t), M t /M ∞ = k pr · t n , where S r and S 0 represent the amount of drug released at time t and the initial amount of the drug in solution, k r is the release constant, M t /M ∞ is the fraction of drug release at a specific contact time t, M t and M ∞ refer to the drug released at time t and at infinite time, respectively, k pr and n represent the gel characteristic constant and the diffusion coefficient, respectively. The type of drug release mechanism can be evaluated considering the n parameter value as follows: Fickian diffusion for n values smaller than 0.5, unidirectional or Fickian diffusion if n is equal to 0.5, anomalous or non-Fickian transport for n values higher than 0.5, Case II transport for n = 1 and supercase II transport for n > 1 [ 48 ].…”

Amphiphilic Chitosan Porous Membranes as Potential Therapeutic Systems with Analgesic Effect for Burn Care

“…Based on the obtained values, lidocaine release capacities over time were calculated, according to the calibration curve previously established ( Figure S2 ). The release data were further processed by applying pseudo-first order (PFO) kinetic model, used to describe the diffusional release mechanisms from porous systems (Equation (7)) [ 41 , 42 ]. Additionally, Korsmeyer–Peppas (K–P) model was used to investigate the lidocaine release mechanism, by processing the first 60% of the experimental data, aiming to describe the lidocaine diffusion mechanisms from the chitosan matrix (Equation (8)) [ 42 ]: where S 0 is the initial amount of the drug and S r represent the cumulative amount of the drug release at time t, k r is the pseudo-first order release constant, M t /M ∞ represents the drug release fraction at time t (M t and M ∞ being the amount of drug released at time t and at infinite time, respectively), k pr is the kinetic K–P constant and n is the characteristic diffusion (release) coefficient, providing information about the type of the release mechanism (n < 0.5—quasi-Fickian diffusion; n = 0.5—unidirectional/Fickian diffusion; 0.5 < n < 1—non-Fickian transport; n = 1—Case II non-Fickian transport; n > 1—non-Fickian supercase II transport [ 43 ].…”

Electrospun zein nanofibers loaded with curcumin as a wound dressing: enhancing properties with PSS and PDADMAC layers

“…where M t represents the amount of released drug over time (t), M 0 is the initial drug amount in the system, k is the drug release constant, and n is the release exponent, revealing the drug release mechanism [46].…”

“…Based on the results, the Korsmeyer-Peppas kinetic model could best describe the release behavior (R 2 > 0.95). In this model, n was less than 0.5 for the coated samples, meaning that the drug diffuses through the partially swollen matrix and solutionfilled networks [46,76,77].…”