pectins and ziprasidone

Novel diethanolamine-grafted high-methoxyl pectin (DGP)-arabic gum (AG) modified montmorillonite (MMT) composites were developed for intragastric ziprasidone HCl (ZIP) delivery by combining floating and mucoadhesion mechanisms. The ZIP-loaded clay-biopolymer matrices were accomplished by ionotropic gelation protocol utilizing zinc acetate in the presence or absence of covalent crosslinker, glutaraldehyde (GA). Various formulations exhibited excellent drug entrapment efficiency (DEE, %) and sustained drug release profiles, which were influenced by the polymer-blend (DGP:AG) ratios, reinforcing filler (MMT) existence and crosslinking procedure. The optimal composites (F-3) demonstrated DEE of 61% and Q8h of 52% with outstanding buoyancy, mucin adsorption ability and biodegradability. The release profile of F-3 was best fitted in the Korsmeyer-Peppas model with Fickian diffusion driven mechanism. The mucin adsorption to composites F-3 followed Freundlich isotherms. The molar mass between crosslinks of composites (F-3) calculated employing Flory-Rehner equation was increased with temperature. Moreover, the thermal, X-ray and infrared analyses confirmed a compatible environment of drug in the composites, except certain extent of transformation of the crystalline drug to its amorphous form. The SEM studies revealed the spherical morphology of the composites. Thus, the newly developed DGP-AG-MMT composites are appropriate for gastroretentive ZIP delivery over an extended period of time.

Topics: Adhesiveness; Adsorption; Bentonite; Drug Carriers; Drug Liberation; Gastric Mucosa; Gum Arabic; Pectins; Piperazines; Surface Properties; Thiazoles

A novel dual crosslinked low-methoxyl (LM) pectinate-sterculia gum (SG) interpenetrating polymer network (IPN) beads was developed for intragastric ziprasidone delivery. The IPN beads were accomplished by simultaneous ionotropic gelation with zinc acetate and covalent crosslinking with glutaraldehyde. The effects of pectin and SG contents on drug entrapment efficiency (DEE, %), and cumulative drug release after 8h (Q8, %) were studied to optimize the IPN beads using a 3(2) factorial design. The optimized beads encapsulating ziprasidone HCl (F-O) displayed DEE of 87.98±1.15% and Q8 of 58.81±1.50% with excellent buoyancy (floating lag time <2min, % buoyancy at 8h >63%) and good mucoadhesivity with the goat gastric mucosa. In most cases, the drug release behaviour obeyed Higuchi kinetics with anomalous transport mechanism. The Zn-pectinate-SG IPN beads were also characterized by SEM, FTIR, DSC and P-XRD analyses.

Topics: Adhesives; Animals; Calorimetry, Differential Scanning; Drug Liberation; Goats; Microspheres; Mucins; Particle Size; Pectins; Piperazines; Plant Gums; Polymers; Spectroscopy, Fourier Transform Infrared; Sterculia; Surface Properties; Thiazoles; X-Ray Diffraction