HPMC-based gastroretentive dual working matrices coated with Ca(+2) ion crosslinked alginate-fenugreek gum gel membrane.

Novel alginate-fenugreek gum (FG) gel membrane coated hydroxypropylmethylcellulose (HPMC) based matrix tablets were developed for intragastric quetiapine fumarate (QF) delivery by combining floating and swelling mechanisms. The effects of polymer blend ratios [HPMC K4M:HPMC E15] and citric acid contents on time taken for 50% drug release (t50%, min) and drug release at 8h (Q8h, %) were studied to optimize the core tablets by 3(2) factorial design. The optimized tablets (F-O) exhibited t50% of 247.67±3.51min and Q8h of 71.11±0.32% with minimum errors in prediction. The optimized tablets were coated with Ca(+2) ions crosslinked alginate-FG gel membrane by diffusion-controlled interfacial complexation technique. The biopolymeric-coated optimized matrices exhibited superior buoyancy, preferred swelling characteristics and slower drug release rate. The drug release profiles of the QF-loaded uncoated and coated optimized matrices were best fitted in Korsmeyer-Peppas model with anomalous diffusion driven mechanism. The uncoated and coated tablets containing QF were also characterized for drug-excipients compatibility, thermal behaviour and surface morphology by FTIR, DSC and SEM analyses, respectively. Thus, the newly developed alginate-FG gel membrane coated HPMC matrices are appropriate for intragastric delivery of QF over a prolonged period of time with greater therapeutic benefits.

Mucoadhesive-floating zinc-pectinate-sterculia gum interpenetrating polymer network beads encapsulating ziprasidone HCl.

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.

Alginate-sterculia gum gel-coated oil-entrapped alginate beads for gastroretentive risperidone delivery.

Novel floating-mucoadhesive oil-entrapped alginate beads coated with crossslinked alginate-sterculia gum gel membrane was developed for gastroretentive risperidone delivery. Oil-entrapped alginate beads containing risperidone as core were prepared by ionotropic gelation technique. Effects of polymer to drug ratio and oil to water ratio on drug entrapment efficiency (%) and cumulative drug release after 8h (%) were studied to optimize the core beads by a 3(2) factorial design. The optimized beads (F-O) demonstrated drug entrapment efficiency of 83.73±0.81% and cumulative drug release of 70.84±0.27% after 8h. The biopolymeric-coated optimized beads exhibited excellent buoyancy, better ex vivo mucoadhesion and slower drug release rate. The drug release profiles of risperidone-loaded uncoated and coated beads were best fitted in Korsmeyer-Peppas model with Fickian diffusion mechanism. The beads were also examined for the drug-excipients compatibility, drug crystallinity and surface morphology by FTIR, P-XRD and SEM analyses, respectively.

Alginate gel-coated oil-entrapped alginate-tamarind gum-magnesium stearate buoyant beads of risperidone.

A novel alginate gel-coated oil-entrapped calcium-alginate-tamarind gum (TG)-magnesium stearate (MS) composite floating beads was developed for intragastric risperidone delivery with a view to improving its oral bioavailability. The TG-blended alginate core beads containing olive oil and MS as low-density materials were accomplished by ionotropic gelation technique. Effects of polymer-blend ratio (sodium alginate:TG) and crosslinker (CaCl2) concentration on drug entrapment efficiency (DEE, %) and cumulative drug release after 8 h (Q8h, %) were studied to optimize the core beads by a 3(2) factorial design. The optimized beads (F-O) exhibited DEE of 75.19±0.75% and Q8h of 78.04±0.38% with minimum errors in prediction. The alginate gel-coated optimized beads displayed superior buoyancy and sustained drug release property. The drug release profiles of the drug-loaded uncoated and coated beads were best fitted in Higuchi kinetic model with Fickian and anomalous diffusion driven mechanisms, respectively. The optimized beads yielded a notable sustained drug release profile as compared to marketed immediate release preparation. The uncoated and coated Ca-alginate-TG-MS beads were also characterized by SEM, FTIR and P-XRD analyses. Thus, the newly developed alginate-gel coated oil-entrapped alginate-TG-MS composite beads are suitable for intragastric delivery of risperidone over a prolonged period of time.