Versatile Drug Delivery System Research Articles

Maintaining Supersaturation of Nimodipine by PVP with or without the Presence of Sodium Lauryl Sulfate and Sodium Taurocholate.

Amorphous solid dispersion (ASD) is one of the most versatile supersaturating drug delivery systems to improve the dissolution rate and oral bioavailability of poorly water-soluble drugs. PVP based ASD formulation of nimodipine (NMD) has been marketed and effectively used in clinic for nearly 30 years, yet the mechanism by which PVP maintains the supersaturation and subsequently improves the bioavailability of NMD was rarely investigated. In this research, we first studied the molecular interactions between NMD and PVP by solution NMR, using CDCl3 as the solvent, and the drug-polymer Flory-Huggins interaction parameter. No strong specific interaction between PVP and NMD was detected in the nonaqueous state. However, we observed that aqueous supersaturation of NMD could be significantly maintained by PVP, presumably due to the hydrophobic interactions between the hydrophobic moieties of PVP and NMD in aqueous medium. This hypothesis was supported by dynamic light scattering (DLS) and supersaturation experiments in the presence of different surfactants. DLS revealed the formation of NMD/PVP aggregates when NMD was supersaturated, suggesting the formation of hydrophobic interactions between the drug and polymer. The addition of surfactants, sodium lauryl sulfate (SLS) or sodium taurocholate (NaTC), into PVP maintained that NMD supersaturation demonstrated different effects: SLS could only improve NMD supersaturation with concentration above its critical aggregation concentration (CAC) value while not with lower concentration. Nevertheless, NaTC could prolong NMD supersaturation independent of concentration, with lower concentration outperformed higher concentration. We attribute these observations to PVP-surfactant interactions and the formation of PVP/surfactant complexes. In summary, despite the lack of specific interactions in the nonaqueous state, NMD aqueous supersaturation in the presence of PVP was attained by hydrophobic interactions between the hydrophobic moieties of NMD and PVP. This hydrophobic interaction could be disrupted by surfactants, which interact with PVP competitively, thus hindering the capability of PVP to maintain NMD supersaturation. Therefore, caution is needed when evaluating such ASDs in vitro and in vivo when various surfactants are present either in the formulation or in the surrounding medium.

Design and tuning of a cell-penetrating albumin derivative as a versatile nanovehicle for intracellular drug delivery

Human serum albumin (HSA) is a superior carrier for delivering extracellular drugs. However, the development of a cell-penetrating HSA remains a great challenge due to its low membrane permeability. We report herein on the design of a series of palmitoyl-poly-arginine peptides (CPPs) and an evaluation of their cell-penetrating effects after forming a complex with HSA for use in intracellular drug delivery. The palmitoyl CPPs forms a stable complex with HSA by anchoring itself to the high affinity palmitate binding sites of HSA. Among the CPPs evaluated, a cyclic polypeptide composed of D-dodecaarginines, palmitoyl-cyclic-(D-Arg)12 was the most effective for facilitating the cellular uptake of HSA by HeLa cells. Such a superior cell-penetrating capability is primarily mediated by macropinocytosis. The effect of the CPP on pharmacological activity was examined using three drugs loaded in HSA via three different methods: a) an HSA-paclitaxel complex, b) an HSA-doxorubicin covalent conjugate and c) an HSA-thioredoxin fusion protein. The results showed that cell-penetrating efficiency was increased with a corresponding and significant enhancement in pharmacological activity. In conclusion, palmitoyl-cyclic-(D-Arg)12/HSA is a versatile cell-penetrating drug delivery system with great potential for use as a nano-carrier for a wide diversity of pharmaceutical applications.

Development and Characterization of Solid Lipid Nanoparticles Loaded with a Highly Active Doxorubicin Derivative.

Solid lipid nanoparticles (SLNs) comprise a versatile drug delivery system that has been developed for the treatment of a variety of diseases. The present study will investigate the feasibility of entrapping an active doxorubicin prodrug (a squalenoyl-derivative) in SLNs. The doxorubicin derivative-loaded SLNs are spherically shaped, have a mean diameter of 300–400 nm and show 85% w/w drug entrapment efficiency. The effects on cell growth of loaded SLNs, free doxorubicin and the prodrug have been examined using cytotoxicity and colony-forming assays in both human ovarian cancer line A2780 wild-type and doxorubicin-resistant cells. Further assessments as to the treatment’s ability to induce cell death by apoptosis have been carried out by analyzing annexin-V staining and the activation of caspase-3. The in vitro data demonstrate that the delivery of the squalenoyl-doxorubicin derivative by SLNs increases its cytotoxic activity, as well as its apoptosis effect. This effect was particularly evident in doxorubicin-resistant cells.

Characterization of charged polymer self-assemblies by multidetector thermal field-flow fractionation in aqueous mobile phases

Charged block copolymer self-assemblies, such as charged micelles, have attracted much attention as versatile drug delivery systems due to their readily tunable characteristics such as size and surface charge. However, current column-based analytical techniques are not suitable to fractionate and comprehensively characterize charged micelles in terms of size, molar mass, chemical composition and morphology. Multidetector thermal field-flow fractionation (ThFFF) is shown to be a unique characterization platform that can be used to characterize charged micelles in terms of size, molar mass, chemical composition and morphology in aqueous mobile phases with various ionic strengths and pH. This is demonstrated by the characterization of poly(methacrylic acid)-b-poly(methyl methacrylate) self-assemblies in high pH buffers as well as the characterization of cationic poly(2-vinyl pyridine)-b-polystyrene and poly(4-vinyl pyridine)-b-polystyrene self-assemblies in low pH buffers. Moreover, it is shown that ThFFF is capable of separating charged micelles according to the corona composition. These investigations prove convincingly that ThFFF is broadly applicable to the comprehensive characterization of amphiphilic self-assemblies even when aqueous mobile phases are used.

Solubility of acyclovir in nontoxic and biodegradable ionic liquids: COSMO-RS prediction and experimental verification

The pharmaceutical industry faces a challenge to find potential solvents for drug molecules that are sparingly soluble in water and conventional organic solvents. Recently, ionic liquids (ILs) have attracted great attention as pharmaceutical solvents owing to their unique physicochemical and biological properties. In this study, the solubility of the sparingly soluble drug molecule acyclovir (ACV) in a wide variety of ILs was investigated by conductor-like screening model for real solvents (COSMO-RS) calculations. The predicted solubilities were validated by experimental measurements, and good agreement was found between the predicted and experimental results. The solubility of ACV was greatly affected by the structure of ILs, particularly the anionic moiety. Among the various ILs tested, ACV showed excellent solubility in ammonium-based ILs with an acetate anion. In vitro cytotoxicity of ILs to the MCF-10 normal breast epithelial cell line and cancer cell lines (MDA MB 231 and MCF 7) was investigated. The ammonium-based ILs showed higher IC50 values than the imidazolium-based ILs with the acetate anion. Biodegradability results showed that diethylammonium acetate, triethylammonium acetate, and choline acetate ILs have high levels of biodegradation under aerobic conditions and can be classified as readily biodegradable. These findings will be useful for the design of IL-based drug delivery carriers that can act as versatile and efficient drug delivery systems for sparingly soluble drug molecules.

Asymmetrical Polymer Vesicles for Drug delivery and Other Applications.

Scientists have been attracted by polymersomes as versatile drug delivery systems since the last two decades. Polymersomes have the potential to be versatile drug delivery systems because of their tunable membrane formulations, stabilities in vivo, various physicochemical properties, controlled release mechanisms, targeting abilities, and capacities to encapsulate a wide range of drugs and other molecules. Asymmetrical polymersomes are nano- to micro-sized polymeric capsules with asymmetrical membranes, which means, they have different outer and inner coronas so that they can exhibit better endocytosis rate and endosomal escape ability than other polymeric systems with symmetrical membranes. Hence, asymmetrical polymersomes are highly promising as self-assembled nano-delivery systems in the future for in vivo therapeutics delivery and diagnostic imaging applications. In this review, we prepared a summary about recent research progresses of asymmetrical polymersomes in the following aspects: synthesis, preparation, applications in drug delivery and others.

Monitoring of "on-demand" drug release using dual tumor marker mediated DNA-capped versatile mesoporous silica nanoparticles.

A versatile drug delivery system with dual specific capacity of controllable release and monitoring of the intracellular release process, which extremely maximize therapeutic efficacy on diseased cells while minimizing drug toxicity to healthy cells, was reported for the first time.

ABACAVIR LOADED NANOPARTICLES: PREPARATION, PHYSICOCHEMICAL CHARACTERIZATION AND IN VITRO EVALUATION

Objectives: Abacavir is a nucleoside analog reverse transcriptase inhibitor (NRTI), antiretroviral drug; it is used in treatment of AIDS. The present study deals with the formulation and evaluation of Abacavir nanoparticles. Methods: Abacavir nanoparticles were formulated by solvent displacement method using Eudragit RL-100, chitosan and Poloxamer-188. Nanoparticles were characterized by determining its particle size, drug entrapment efficiency, particle morphological character and in-vitro drug release. Results: Particle size range of nanoparticles was in the range of 121.4-140.6 nm. Zeta potential of formulations was determined, and it was found in range of 16.5-20.45 mv. The in-vitro release of nanoparticles were carried out which exhibited a sustained release of Abacavir from nanoparticles up to 10 hrs. Conclusion: The study concludes that nanoparticles can be a promising drug delivery system for sustained release of Abacavir in terms of increased bioavailability. Peer Review History: Article received on- 15 November Revised on- 10 December Accepted on- 15 December, Available online 15 January 2017 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 4.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Kingsley C Anukam, University of Benin, Nigeria, kanukam@gmail.com Dr. Iman Muhammad Higazy, National Research Center, Egypt, imane.higazy@hotmail.com Similar Articles: NANOSPONGES: A NEW ERA OF VERSATILE DRUG DELIVERY SYSTEM

Taste masking of ofloxacin and formation of interpenetrating polymer network beads for sustained release

The objective of this study was to carry out taste masking of ofloxacin (Ofl) by ion exchange resins (IERs) followed by sustained release of Ofl by forming interpenetrating polymer network (IPN) beads. Drug-resin complexes (DRCs) with three different ratios of Ofl to IERs (1:1, 1:2, 1:4) were prepared by batch method and investigated for in vivo and in vitro taste masking. DRC of methacrylic acid-divinyl benzene (MD) resin and Ofl prepared at a ratio of 1:4 was used to form IPN beads. IPN beads of MD 1:4 were prepared by following the ionic cross-linking method using sodium carboxymethyl xanthan gum (SCMXG) and SCMXG-sodium carboxymethyl cellulose (SCMXG-SCMC). IPN beads were characterized with FT-IR and further studied on sustained release of Ofl at different pH. In vivo taste masking carried out by human volunteers showed that MD 1:4 significantly reduced the bitterness of Ofl. Characterization studies such as FT-IR, DSC, P-XRD and taste masking showed that complex formation took place between drug and resin. In vitro study at gastric pH showed complete release of drug from MD 1:4 within 30min whereas IPN beads took 5h at gastric pH and 10h at salivary pH for the complete release of drug. As the crosslinking increased the release kinetics changed into non-Fickian diffusion to zero-order release mechanism. MD 1:4 showed better performance for the taste masking of Ofl and IPNs beads prepared from it were found useful for the sustained release of Ofl at both the pH, indicating a versatile drug delivery system.

Nanoceria-Mediated Drug Delivery for Targeted Photodynamic Therapy on Drug-Resistant Breast Cancer.

Photodynamic therapy (PDT) has shown great potential for overcoming drug-resistant cancers. Here, we report a multifunctional drug delivery system based on chlorin e6 (Ce6)/folic acid (FA)-loaded branched polyethylenimine-PEGylation ceria nanoparticles (PPCNPs-Ce6/FA), which was developed for targeted PDT to overcome drug-resistant breast cancers. Nanocarrier delivery and FA targeting significantly promoted the cellular uptake of photosensitizers (PSs), followed by their accumulation in lysosomes. PPCNPs-Ce6/FA generated reactive oxygen species (ROS) after near-infrared irradiation (NIR, 660 nm), leading to reduced P-glycoprotein (P-gp) expression, lysosomal membrane permeabilization (LMP), and excellent phototoxicity toward resistant MCF-7/ADR cells, even at ultralow doses. Moreover, we identified NIR-triggered lysosomal-PDT using the higher dose of PPCNPs-Ce6/FA, which stimulated cell death by plasma membrane blebbing, cell swelling, and energy depletion, indicating an oncosis-like cell death pathway, despite the occurrence of apoptotic or autophagic mechanisms at lower drug doses. In vivo studies showed prolonged blood circulation times, low toxicity in mice, and high tumor accumulation of PPCNPs-Ce6/FA. In addition, using NIR-triggered PDT, PPCNPs-Ce6/FA displayed excellent potency for tumor regression in the MCF-7/ADR xenograft murine model. This study suggested that multifunctional PPCNPs-Ce6/FA nanocomposites are a versatile and effective drug delivery system that may potentially be exploited for phototherapy to overcome drug-resistant cancers, and the mechanisms of cell death induced by PDT should be considered in the design of clinical protocols.

Delivery system for berberine chloride based on the nanocarrier ZnAl-layered double hydroxide: Physicochemical characterization, release behavior and evaluation of anti-bacterial potential

Layered double hydroxide (LDH) has attracted major interest as one of the most versatile drug delivery systems especially for adsorption capacity and/or controlled delivery property of bioactive agents owing to their combining features of biohybrid. ZnAl synthesized layered double hydroxide can offer a platform to immobilize various types of bioactive compounds, particularly berberine chloride (BBC). However, the immobilization reaction of berberine chloride into ZnAl-LDH was performed by direct co-precipitation method at different ratios of BBC/LDH. BBC–ZnAl-LDH biohybrids were characterized in terms of structure, surface morphology, in vitro drug release profile and antibacterial assay against various bacterial cells. The BBC biomolecules were attached by coordinate bond. Structural and microstructural characterization confirms that interaction of BBC with ZnAl-LDH occurs by adsorption rather than intercalation of BBC within LDH layers. The BBC release profiles from BBC–ZnAl-LDH had a longer release duration compared to the physical mixture, and the drug release seemed faster with the low ratio of BBC/LDH. BBC−ZnAl-LDH can be internalized into bacterial cells. In vitro experiments in PBS medium showed that BBC−ZnAl-LDH biohybrid had higher cytotoxicity and inhibitory effects against three pathogenic bacteria; Staphylococcus aureus CIP 543154, Pseudomonas aeruginosa A22 and Bacillus subtilus ILP 1428B upon the drug release profiles and its destructive potential depends on the loading BBC on the LDH layers. Nonetheless these results prove that the prepared BBC–ZnAl-LDH biohybrids retain the anti-bacterial character of the BBC molecules and are therefore potential modified drug delivery system (DDS).

Highly Versatile Polyelectrolyte Complexes for Improving the Enzyme Replacement Therapy of Lysosomal Storage Disorders.

Lysosomal storage disorders are currently treated by enzyme replacement therapy (ERT) through the direct administration of the unprotected recombinant protein to the patients. Herein we present an ionically cross-linked polyelectrolyte complex (PEC) composed of trimethyl chitosan (TMC) and α-galactosidase A (GLA), the defective enzyme in Fabry disease, with the capability of directly targeting endothelial cells by incorporating peptide ligands containing the RGD sequence. We assessed the physicochemical properties, cytotoxicity, and hemocompatibility of RGD-targeted and untargeted PECs, the uptake by endothelial cells and the intracellular activity of PECs in cell culture models of Fabry disease. Moreover, we also explored the effect of different freeze-drying procedures in the overall activity of the PECs. Our results indicate that the use of integrin-binding RGD moiety within the PEC increases their uptake and the efficacy of the GLA enzyme, while the freeze-drying allows the activity of the therapeutic protein to remain intact. Overall, these results highlight the potential of TMC-based PECs as a highly versatile and feasible drug delivery system for improving the ERT of lysosomal storage disorders.

Protein Nanoparticle as a Versatile Drug Delivery System in Nanotechnology

Protein Nanoparticle as a Versatile Drug Delivery System in Nanotechnology

Precise Microscale Polymeric Networks through Piezoelectronic Inkjet Printing.

Microsized particles are versatile drug delivery systems with applications as inhalants, implants, and vaccines. An ideal fabrication technique is envisioned to provide particles with controlled size dimensions and is facile, without excessive loss of drug during incorporation, modulated morphologies and release kinetics. In this work, we report on the utilization of a set of polymeric building blocks such as allyl- functionalized polycarbonates, semibranched poly(glycidol allylglycidyl ether)s, and dithiol-PEG cross-linkers to form microsized networks in controlled size dimensions of 18-12 μm, 12-8 μm, and 1-2 μm with modulated morphologies and hydrophilicity based on the ratio of the polycarbonate or polyglycidol building blocks. Piezoelectric ink jet printing allows for the direct printing of these polymeric structures onto substrates, after which the printed droplet is cross-linked via UV light using thiol-ene click reactions. By varying the ratio of the allyl-functionalized building block droplets from being purely prepared either from polycarbonate (PC), polyglycidol (PG) backbones or in a ratio of 70/30 of functionalized polycarbonates and polyglycidols, the droplets can be either printed in DMSO or water. Preliminary studies to control the particle sizes not only through the droplet volume but also by reducing the polymer concentration by 20%, resulted in another set of 70/30 polycarbonate/polyglycidol micron sized networks with an observed corresponding size reduction of 20%. With this, we have developed a facile technique to prepare microsized hydrogel particles with homogeneous and attractive size dimensions that can be directly prepared without using lithography methodologies. The strength of the approach is the set of unique polymeric building blocks that in combination with the new technique allows for a modulation of hydrophilicity and morphologies to form promising drug delivery candidates to carry and release synthetic as well as biological cargo.

Bio-inspired nanovesicles as a versatile drug delivery system for imaging-guided cancer therapy

Bio-inspired nanovesicles as a versatile drug delivery system for imaging-guided cancer therapy

Intracellular pH-Triggered, Targeted Drug Delivery to Cancer Cells by Multifunctional Envelope-Type Mesoporous Silica Nanocontainers.

In this work, a novel type of pH-sensitive multifunctional envelope-type mesoporous silica nanocontainers (SBDAPF) was constructed for targeted drug delivery to cancer cells. Poly(N-succinimidyl acrylate) was coated on the mesoporous silica nanoparticles surface via an acid-labile acetal linker to obtain the SBA particles for pH-triggered drug release. A model drug doxorubicin (DOX)-loaded SBA system (SBDA) showed low premature drug release at neutral pH and effective stimuli-responsive release under the acidic conditions. To provide the colloidal stability and avoid nonspecific uptake of normal or healthy cells, the SBDA nanocontainers were modified with a poly(ethylene glycol) (PEG) polymer to form a protection layer. Furthermore, folic acid was introduced as a targeting component and anchored on the PEG outer layer to achieve the cancer-targeting ability. In vitro study demonstrated that SBDAPF could selectively adhere to the surface of cancer cells through the specific binding with folate receptor and be internalized into cells, subsequently releasing the entrapped DOX with high efficiency in slightly acidic intracellular microenvironment to finally kill cancer cells. Such a versatile drug delivery system as SBDAPF should have a potential application in cancer therapy.

Galactose-based Thermosensitive Nanogels for Targeted Drug Delivery of Iodoazomycin Arabinofuranoside (IAZA) for Theranostic Management of Hypoxic Hepatocellular Carcinoma.

In this study, galactose-based nanogels were prepared by reversible addition-fragmentation chain transfer process to facilitate the targeted delivery of iodoazomycin arabinofuranoside (IAZA), a clinical drug for imaging solid hypoxic tumors, and evaluate its role in hypoxia-selective (radio)theranostic (therapy + diagnostic) management of therapy-resistant cancer cells. The nanogels have a cross-linked temperature-responsive core and a dense carbohydrate shell. Their thermoresponsive nature allowed the controlled encapsulation of IAZA drug for targeted delivery and release in hypoxic hepatocellular carcinoma via asialoglycoprotein receptor-mediated uptake. The synthesized nanogel-IAZA delivery systems demonstrated a stable, nonburst release of IAZA over 10 h with up to 0.6 mM loading capacity of IAZA within the nanogel. The cytotoxicity evaluations of the nanogels demonstrated that they are relatively nontoxic in multiple cell lines. The radiosensitization studies indicated that IAZA in encapsulated form offers a superior radiosensitization of hypoxic cells (sensitizer enhancement ratio for IAZA alone, 1.33; 1.62 for nanogel encapsulated IAZA). These studies suggest that galactose-based nanogels may serve as a versatile drug delivery system for IAZA (and other azomycin-based agents) and enable its hypoxia-selective multimodal theranostic applications to manage hypoxic solid (hepatocellular) tumors by facilitating position/single photon emission tomography-based imaging, external beam radiation therapy, and in situ molecular radiotherapy.

Formulation and Evaluation of Mucoadhesive Buccal Tablets of Repaglinide

Objective: Delivery of the desired drug as mucoadhesive drug delivery systems has been subject of interest since 1980s. The various advantages associated with these systems made the buccal drug delivery as a novel route of drug administration. Buccal region offers an attractive route for the administration of systemic drug delivery. The objective of the study was to develop mucoadhesive buccal tablets of repaglinide. Methodology: The tablets were prepared by wet granulation method using a combination of mucoadhesive polymers like chitosan, hydroxyethyl cellulose, guar gum and carbopol 934P in different ratios. Results: Buccal tablets were evaluated by different methods for parameters such as thickness, hardness, weight uniformity, drug content uniformity, surface pH, ex vivo mucoadhesive strength, ex vivo residence time, in vitro drug release, ex vivo drug permeation. The tablets were evaluated for in vitro release in phosphate buffer of pH 6.8 for 12 h. In order to determine the mode of release, the data was subjected to zero order, first order, Higuchi and Korsmeyer-Peppas model. The mucoadhesive strength was evaluated by measuring the force required to detach the tablets from sheep buccal mucosal membrane. Carbopol 934P showed maximum mucoadhesion and required maximum force for detachment; the force required for detachment was directly proportional to its content. DSC and XRD study of the pure drug indicated that the drug is in the crystalline form. But in the formulations, peaks indicated that the drug is in the amorphous form. FTIR spectroscopic studies indicated that there is no drug-excipient interaction. Conclusion: The prepared formulations showed good mucoadhesive strength and ability to sustain the drug release over 12 h; hence, these are the versatile drug delivery systems for repaglinide.

Self-assembled core-shell nanoparticles for combined chemotherapy and photodynamic therapy of resistant head and neck cancers.

Combination therapy enhances anticancer efficacy of both drugs via synergistic effects. We report here nanoscale coordination polymer (NCP)-based core-shell nanoparticles carrying high payloads of cisplatin and the photosensitizer pyrolipid, NCP@pyrolipid, for combined chemotherapy and photodynamic therapy (PDT). NCP@pyrolipid releases cisplatin and pyrolipid in a triggered manner to synergistically induce cancer cell apoptosis and necrosis. In vivo pharmacokinetic and biodistribution studies in mice show prolonged blood circulation times, low uptake in normal organs, and high tumor accumulation of cisplatin and pyrolipid. Compared to monotherapy, NCP@pyrolipid shows superior potency and efficacy in tumor regression (83% reduction in tumor volume) at low drug doses in the cisplatin-resistant human head and neck cancer SQ20B xenograft murine model. We elucidated the in vitro/vivo fate of the lipid layer and its implications on the mechanisms of actions. This study suggests multifunctional NCP core-shell nanoparticles as a versatile and effective drug delivery system for potential translation to the clinic.

Robust and versatile pectin-based drug delivery systems

Pectin-based resistant, interactive and versatile hydrogel vehicles for oral administration have been prepared. These systems are thought to be versatile enough to allow the inclusion of substances (such as the surfactants tested: Pluronic, Tween, Na Lauryl sulphate) that may contribute to tailor the drug release patterns. Tolbutamide, that shows a discrete and pH-dependent solubility in water, has been employed as a model drug to test the capability of these matrices to overcome such drug-imposed restraints. The incorporation of different surfactants produced pectin-based hydrogels of difficult manipulation. In order to improve this drawback, two different strategies have been developed: blending with agarose or freeze-drying. The presence of agarose yields robust systems that can be handled and tested as prepared, in the fresh state. Freeze-drying not only allows to shape pure pectin and blend systems, but also generates a porous structure whose microstructure, determined by the different components included, influences on the drug release behavior. Tolbutamide release kinetics from freshly prepared matrices can be fitted to the Higuchi model while the freeze-dried ones adjust to the Korsmeyer–Peppas model; hence the hydrogel chains rearrangement processes rule the release during the rehydration process.