A Co-blended Locust Bean Gum and Polymethacrylate-NaCMC Matrix to Achieve Zero-Order Release via Hydro-Erosive Modulation.

Locust bean gum (LBG) was blended with a cellulose/methacrylate-based interpolyelectrolyte complex (IPEC) to assess the hydro-erosive influence of addition of a polysaccharide on the disposition and drug delivery properties inherent to IPEC matrix. The addition of LBG modulated the drug (levodopa) release characteristics of the IPEC by reducing excessive swelling and preventing bulk erosion. After 8 h in pH 4.5 dissolution medium, gravimetric analysis established that IPEC tablet matrix eroded by 30% of the initial weight due to bulk erosion while LBG-blended IPEC (LBG-b-IPEC) demonstrated surface erosion accounting to 62% of initial weight (596→226.8 mg). Mathematical modeling of the drug release data depicted a transformation from non-Fickian mechanism (IPEC matrices) to zero-order drug release pattern (LBG-b-IPEC matrices) with the linearity of release profile being close to 1 (R (2) = 0.99). Physicochemical characterizations employing Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) explicated that LBG interacted with IPEC by its hydrophilic groups associating with the existing water-holding bodies of IPEC to produce compact matrices. The lattice atomistic modeling elucidated that LBG acted as a linker with the formation of intra- and intermolecular hydrogen bonds generating a highly stabilized polysaccharide-polyelectrolytic structure which influenced the improved properties observed.