Interpenetrating polymer network microcapsules of gellan gum and egg albumin entrapped with diltiazem–resin complex for controlled release application

Biofabrication of aminated nanocellulose reinforced polyvinyl alcohol/chitosan nanofibrous scaffold for sustained release of diltiazem hydrochloride

In the modern environment conscious era, there has been a huge demand for the effective green method to fabricate biomaterials for sustained transdermal release of diltiazem hydrochloride to treat hypertension and cardiac failure. In this vein, the present study explores the amination of waste jute sourced nanocellulose (ANC) and its effect as a reinforcing filler to design electrospun polyvinyl alcohol (PVA)/chitosan based polymeric nanofibrous scaffold for drug delivery. The characterization results of FTIR (Fourier Transform Infrared Spectroscopy) confirm the successful chemical modification of nanocellulose (NCC). SEM (Scanning Electron Microscopy) results indicate the morphological modifications in ANC due to grafting. ANC enhances the mechanical properties of scaffold and sustains the release of the loaded drug to 67.89±3.39% as compared to the pure PVA/chitosan scaffold of 92.63±4.63% over a period of 72 h as shown by the results of in-vitro drug release study. Moreover, the incorporation of 0.5 % ANC improves the anti-bacterial activity against both gram-positive (97.4±4.87%, reduction in viable cells count) and gram-negative bacteria (98.5±4.93%, reduction in viable cells count). Further, the skin irritation and MTT assay authenticate the biocompatibility of the developed scaffold. The overall findings hence prove the efficacy of the engineered scaffold as a potential transdermal patch for sustained drug delivery applications.

Effect of intragranular/extragranular tara gum on sustained gastrointestinal drug delivery from semi-IPN hydrogel matrices

The present research was undertaken to develop semi-IPN hydrogel matrix tablets of tara gum (TG) and carboxymethyl TG (CMTG) for sustained gastrointestinal delivery of highly water soluble tramadol hydrochloride (TH). The matrix tablets were developed by a hybrid process of wet granulation and direct compression technique. Carboxymethyl TG was crosslinked with dual cross-linking ions (Al3+/Ca2+). The uncross-linked component of the semi-IPN matrix was either incorporated within the granules (intragranular TG) or incorporated outside the granules (extragranular TG), prior to compression. The effect of intragranular/extragranular TG on the swelling, erosion and TH release characteristics from the semi-IPN hydrogel matrix tablets was investigated. The key finding of the investigation indicated that intragranular TG expedited TH release, while extragranular TG sustained TH release. Moreover, the effect of cross-linking ions on viscosity, rigidity, cross-link density and TH release behavior from hydrogel matrices was investigated. In-vivo pharmacokinetic performance of the optimized extragranular TG semi-IPN hydrogel matrix (F15) indicated sustained TH release in gastrointestinal milieu.

Mussel-inspired self-healing hydrogel based on gelatin and oxidized tannic acid for pH-responsive controlled drug release

A series of mussel-inspired pH-responsive self-healing hydrogels based on gelatin crosslinked by oxidized tannic acid (GLT-OTAs) were prepared and used as controlled drug delivery systems (CDDS). An antiphlogistic drug, indomethacin (IDMC) was used as model drug to be immobilized into the hydrogels. The obtained hydrogel samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical stability, biocompatibility and self-healing property of the hydrogels were estimated, respectively. Swelling and drug release behaviors of these hydrogels were measured in phosphate buffered saline (PBS) with pH 7.4 (simulated intestinal fluid) and HCl solution with pH 1.2 (simulated gastric fluid) at 37 °C. Effect of the OTA content on the structures and characteristics of all samples was discussed. FTIR spectra revealed the covalent cross-linking between gelatin and OTA induced by Michael addition and Schiff base reaction. Both XRD and FTIR all showed the drug (IDMC) was loaded successfully and existed steadily. GLT-OTA hydrogels had satisfactory biocompatibility, superior self-healing. Results also illustrated that the mechanical strength, internal structure, the swelling and drug release behaviors of the GLT-OTAs hydrogel were greatly affected by the OTA content. With increasing the OTA content, the mechanical stability of GLT-OTAs hydrogel became better and better, and their internal structure became more and more compact. The swelling degree (SD) and cumulative drug release of all hydrogel samples tended to decrease with increasing OTA content and both had obvious pH responsiveness. For each hydrogel sample, the cumulative drug release in PBS at pH 7.4 was greater than that in HCl solution at pH 1.2. These results indicated that the obtained GLT-OTAs hydrogel had promising potential to be used as effective pH-responsive and self-healing drug delivery materials.

Ionotropic Gelation and Chemical Crosslinking as Methods for Fabrication of Modified-Release Gellan Gum-Based Drug Delivery Systems

Hydrogels have a tridimensional structure. They have the ability to absorb a significant amount of water or other natural or simulated fluids that cause their swelling albeit without losing their structure. Their properties can be exploited for encapsulation and modified targeted drug release. Among the numerous natural polymers suitable for obtaining hydrogels, gellan gum is one gaining much interest. It is a gelling agent with many unique features, and furthermore, it is non-toxic, biocompatible, and biodegradable. Its ability to react with oppositely charged molecules results in the forming of structured physical materials (films, beads, hydrogels, nanoparticles). The properties of obtained hydrogels can be modified by chemical crosslinking, which improves the three-dimensional structure of the gellan hydrogel. In the current review, an overview of gellan gum hydrogels and their properties will be presented as well as the mechanisms of ionotropic gelation or chemical crosslinking. Methods of producing gellan hydrogels and their possible applications related to improved release, bioavailability, and therapeutic activity were described.

Advances in fermentative production, purification, characterization and applications of gellan gum

Multiple microbial exopolysaccharides have been reported in recent decade with their structural and functional features. Gellan gum (GG) is among these emerging biopolymers with versatile properties. Low production yield, high downstream cost, and abundant market demand have made GG a high cost material. Hence, an understanding on the various possibilities to develop cost-effective gellan gum bioprocess is desirable. This review focuses on details of upstream and downstream process of GG from an industrial perspective. It emphasizes on GG producing Sphingomonas spp., updates on biosynthesis, strain and media engineering, kinetic modeling, bioreactor design and scale-up considerations. Details of the downstream operations with possible modifications to make it cost-effective and environmentally sustainable have been discussed. The updated regulatory criteria for GG as a food ingredient and analytical tools required to validate the same have been briefly discussed. Derivatives of GG and their applications in various industrial segments have also been highlighted.

Ammonio Methacrylate Copolymer (Type B)-Diltiazem Interactions in Solid Dispersions and Microsponge Drug-Delivery Systems

This paper presents a complex analytical study on the distribution, solubility, amorphization, and compatibility of diltiazem within the composition of Eudragit RS 100-based particles of microspongeous type. For this purpose, a methodology combining attenuated total reflectance Fourier transform infrared (ATR-FTIR) absorption spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy with energy-dispersive X-ray microanalysis (SEM-EDX), and in vitro dissolution study is proposed. The correct interpretation of the FTIR and drug-dissolution results was guaranteed by the implementation of two contrasting reference models: physical drug–polymer mixtures and casting-obtained, molecularly dispersed drug–polymer composites (solid dispersions). The spectral behavior of the drug–polymer composites in the carbonyl frequency (νCO) region was used as a quality marker for the degree of their interaction/mutual solubility. A spectral-pattern similarity between the microsponge particles and the solid dispersions indicated the molecular-type dispersion of the former. The comparative drug-desorption study and the qualitative observations over the DSC and SEM-EDX results confirmed the successful synthesis of a homogeneous coamorphous microsponge-type formulation with excellent drug-loading capacity and “controlled” dissolution profile. Among them, the drug-delivery particles with 25% diltiazem content (M-25) were recognized as the most promising, with the highest population of drug molecules in the polymer bulk and the most suitable desorption profile. Furthermore, an economical and effective analytical algorithm was developed for the comprehensive physicochemical characterization of complex delivery systems of this kind.

Evaluation of gum ghatti-g-poly(itaconic acid) magnetite nanocomposite as an adsorbent material for water purification

A porous hydrogel nanocomposite has been made by grafting poly(itaconic acid) on the polysaccharide, gum ghatti and by embedding magnetite nanoparticles in the copolymer gel matrix. This novel functional material Ggh-g-PIA/Fe₃O₄ was characterized by FTIR, TGA, SEM, EDS, XRD, BET, Zeta potential measurements and VSM techniques. The nanocomposite possesses mesoporous structure with high surface area and exhibits super-paramagnetic behavior due to the presence of magnetite nanoparticles. The hydrogel nanocomposite was evaluated as an adsorbent material for removal of dyes and divalent metal ions. Significant adsorption capacities of 410.2, 387.6, 416.5 and 401.4 mg g^-1 towards methylene blue, rhodamine 6G, Cu (II) and Hg (II) ions respectively were observed. The adsorption isotherms were well described by the Freundlich isotherm model and kinetic studies demonstrated the adsorption to be a pseudo second order kinetic process. Intraparticle diffusion model suggested adsorption to occur by a multi-step diffusion process. Thermodynamic studies indicated a spontaneous and endothermic adsorption. Further, the desorption study indicated the possibility of successful regeneration of the adsorbent. A high removal efficiency, recyclability, convenient recovery after use due to the magnetic nature makes this polysaccharide based nanocomposite an environment friendly adsorbent material for water purification.

Synthesis, characterization and fabrication of sodium carboxymethyl-okra-gum-grafted-polymethacrylamide into sustained release tablet matrix

The objective of the present study was to modify okra gum (Abelmoschus esculentus) by carboxymethylation and subsequent graft-copolymerization, characterize and fabricate into sustained-release tablet matrix. Firstly, okra gum was carboxymethylated using sodium hydroxide and monochloroacetic acid followed by grafting with polymethacrylamide employing synergistic combination of free-radical-initiator and microwave-irradiation. The FTIR, NMR, elemental analysis and viscosity study corroborate the formation of sodium-carboxymethyl-okra gum-grafted-polymethacrylamide copolymer (SCMOG-g-PMA). The maximum degree of carboxymethyl-substitution (DCS) and % grafting (%G) were found to be 0.604 ± 0.011 and 644.1, respectively. Water-uptake-capacity was found to increase by 3.5 fold. The tablet formulation of diclofenac sodium with SCMOG-g-PMA (DCS 0.604 and 423.4% G) showed to exhibit excellent sustained-release capacity with 90% drug-release at 11.7 h and similarity-factor of 72.0. The toxicity and biodegradability study also exhibited the bio-compatible and biodegradable nature of the copolymer, which might make the copolymer suitable for sustained-release drug delivery systems as smart semi-synthetic biopolymer.

In vitro and in vivo evaluation of gellan gum hydrogel films: Assessing the co impact of therapeutic oils and ofloxacin on wound healing

Herein, we report co-encapsulation of ofloxacin with tea tree or lavender oil in gellan gum based hydrogel films by solvent casting ionotropic gelation method as wound dressing. Prepared films were transparent, flexible, and displayed antioxidant activity with superior antibacterial response against common inhabitants of wound i.e. gram positive and negative bacteria. Solid-state characterization of optimized formulation (OL3 and OT3) revealed successful incorporation of drug and oils in hydrogel structure without any noticeable interaction. In vitro release studies showed an initial burst release but remaining portion released in controlled manner over 48 h from the films and furthermore, presence of oils did not affected the ofloxacin release. Optimized formulation containing ofloxacin and 25% w/w lavender/tea tree oil showed 98% wound contraction in rats after ten days of treatment. Histological images displayed completely healed epidermis. Taken together, our prepared hydrogel films demonstrated favorable features with appreciable antibacterial, wound healing activity and could be useful for the treatment of full thickness wounds.

Burgeoning Polymer Nano Blends for Improved Controlled Drug Release: A Review

With continual rapid developments in the biomedical field and understanding of the important mechanisms and pharmacokinetics of biological molecules, controlled drug delivery systems (CDDSs) have been at the forefront over conventional drug delivery systems. Over the past several years, scientists have placed boundless energy and time into exploiting a wide variety of excipients, particularly diverse polymers, both natural and synthetic. More recently, the development of nano polymer blends has achieved noteworthy attention due to their amazing properties, such as biocompatibility, biodegradability and more importantly, their pivotal role in controlled and sustained drug release in vitro and in vivo. These compounds come with a number of effective benefits for improving problems of targeted or controlled drug and gene delivery systems; thus, they have been extensively used in medical and pharmaceutical applications. Additionally, they are quite attractive for wound dressings, textiles, tissue engineering, and biomedical prostheses. In this sense, some important and workable natural polymers (namely, chitosan (CS), starch and cellulose) and some applicable synthetic ones (such as poly-lactic-co-glycolic acid (PLGA), poly(lactic acid) (PLA) and poly-glycolic acid (PGA)) have played an indispensable role over the last two decades for their therapeutic effects owing to their appealing and renewable biological properties. According to our data, this is the first review article highlighting CDDSs composed of diverse natural and synthetic nano biopolymers, blended for biological purposes, mostly over the past five years; other reviews have just briefly mentioned the use of such blended polymers. We, additionally, try to make comparisons between various nano blending systems in terms of improved sustained and controlled drug release behavior.

Formulation of Extended-Release Beads of Lamotrigine Based on Alginate and <i>Cassia fistula</i> Seed Gum by QbD Approach

AIM

This study was focused on the formulation of the multi-unit extended-release peroral delivery device of lamotrigine for better management of epilepsy.

BACKGROUND

The single-unit extended-release peroral preparations often suffer from all-or-none effect. A significant number of multi-unit delivery systems have been reported as a solution to this problem. But most of them are found to be composed of synthetic, semi-synthetic or their combination having physiological toxicity as well as negative environmental impact. Therefore, fabrication and formulation of multi-unit extended-release peroral preparations with natural, non-toxic, biodegradable polymers employing green manufacturing processes are being appreciated worldwide.

OBJECTIVE

Lamotrigine-loaded extended-release multi-unit beads have been fabricated with the incorporation of a natural polysaccharide Cassia fistula seed gum in calcium-cross-linked alginate matrix employing a simple green process and 23 full factorial design.

METHODS

The total polymer concentration, polymer ratio and [CaCl2] were considered as independent formulation variables with two different levels of each for the experiment-design. The extended-release beads were then prepared by the ionotropic gelation method using calcium chloride as the crosslinkerions provider. The beads were then evaluated for drug encapsulation efficiency and drug release. ANOVA of all the dependent variables such as DEE, cumulative % drug release at 2h, 5h, 12h, rate constant and dissolution similarity factor (f2) was done by 23 full factorial design using Design-Expert software along with numerical optimization of the independent variables in order to meet USP-reference release profile.

RESULTS

The optimized batch showed excellent outcomes with DEE of 84.7 ± 2.7 (%), CPR2h of 8.41± 2.96 (%), CPR5h of 36.8± 4.7 (%), CPR12h of 87.3 ± 3.64 (%) and f2 of 65.9.

CONCLUSION

This approach of the development of multi-unit oral devices utilizing natural polysaccharides might be inspiring towards the world-wide effort for green manufacturing of sustained-release drug products by the QbD route.

Determination of charge carrier transport properties of gellan gum–lithium triflate solid polymer electrolyte from vibrational spectroscopy

Mobility and number density of charge carriers are important parameters that influence the electrolyte conductivity. Therefore, knowing these parameters quantitatively is of great significance. In this work, solid polymer electrolytes have been prepared by solution casting technique using gellan gum complexes with lithium triflate (LiTf). The conductivity of the electrolyte increases from 3.35 × 10−8 S cm−1 (electrolyte with 10 wt% LiTf) to 5.38 × 10−4 S cm−1 (electrolyte with 40 wt% LiTf). The increase in conductivity was attributed to the increase in mobility and number density of charge carriers in the electrolyte from 6.63 × 10−9 cm2 V−1 s−1 to 1.25 × 10−6 cm2 V−1 s−1 and from 4.00 × 1020 cm−3 to 2.68 × 1021 cm−3, respectively. The electrolyte conductivity is seen to decrease as LiTf salts were added more than 40 wt% concentration due to the decrease of charge carrier mobility to 8.58 × 10−7 cm2 V−1 s−1. The variation of conductivity obtained in this work is dominantly influenced by the mobility of charge carriers in the electrolyte as proven from the Fourier transform infrared approach.

Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

Starch, alginate, and poly(N-isopropylacrylamide) (PNIPAAm) were combined to prepare a semi-interpenetrating network (IPN) hydrogel with temperature sensitivity. Calcium chloride was used as cross-linking agent, the non-toxigenic Aspergillus flavus spores were successfully encapsulated as biocontrol agents by the method of ionic gelation. Characterization of the hydrogel was performed by Fourier-transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), and thermogravimetry analysis (TGA). Formulation characteristics, such as entrapment efficiency, beads size, swelling behavior, and rheological properties were evaluated. The optical and rheological measurements indicated that the lower critical solution temperature (LCST) of the samples was about 29-30 °C. TGA results demonstrated that the addition of kaolin could improve the thermal stability of the semi-IPN hydrogel. Morphological analysis showed a porous honeycomb structure on the surface of the beads. According to the release properties of the beads, the semi-IPN hydrogel beads containing kaolin not only have the effect of slow release before peanut flowering, but they also can rapidly release biocontrol agents after flowering begins. The early flowering stage of the peanut is the critical moment to apply biocontrol agents. Temperature-sensitive hydrogel beads containing kaolin could be considered as carriers of biocontrol agents for the control of aflatoxin in peanuts.

Antibacterial nanostructures derived from oxidized sodium alginate-ZnO

The present study describes synthesis, characterization and antibacterial application of oxidized sodium alginate (OSA)-zinc oxide (ZnO) hybrid nanostructures (OSA-ZnO). In continuation to our previous study on oxidized guar gum (OGG)-ZnO (OGG-ZnO) nanocomposite, in the present study we have chosen OSA to understand the role of polysaccharide charge type in designing the antibacterial material. The nanomaterial has been characterized using UV-visible, FTIR, XRD, SEM and TEM analyses. The nanostructure has shown crystalline nature having hexagonal phase with preferred (101) orientation, while TEM image indicated that the material has ~6 nm particle size. It exhibited very good antibacterial performance against Bacillus subtilis (B. subtilis), Cellulomonas cellulans (C. cellulans), Staphylococcus typhi (S. typhi), and Escherichia coli (E. coli) bacterial strains, ZOI for B. subtilis, C. cellulans, S. typhi, and E. coli being 22, 18, 19.5 and 18.5 mm respectively. Under identical conditions, pure ZnO showed significantly lower ZOI for the corresponding bacterial strains (14, 12.5, 12 and 13.5 mm respectively), while native SA and OSA did not exhibit any biological activity.

Biological Role of Gellan Gum in Improving Scaffold Drug Delivery, Cell Adhesion Properties for Tissue Engineering Applications

Over the past few decades, gellan gum (GG) has attracted substantial research interest in several fields including biomedical and clinical applications. The GG has highly versatile properties like easy bio-fabrication, tunable mechanical, cell adhesion, biocompatibility, biodegradability, drug delivery, and is easy to functionalize. These properties have put forth GG as a promising material in tissue engineering and regenerative medicine fields. Nevertheless, GG alone has poor mechanical strength, stability, and a high gelling temperature in physiological conditions. However, GG physiochemical properties can be enhanced by blending them with other polymers like chitosan, agar, sodium alginate, starch, cellulose, pullulan, polyvinyl chloride, xanthan gum, and other nanomaterials, like gold, silver, or composites. In this review article, we discuss the comprehensive overview and different strategies for the preparation of GG based biomaterial, hydrogels, and scaffolds for drug delivery, wound healing, antimicrobial activity, and cell adhesion. In addition, we have given special attention to tissue engineering applications of GG, which can be combined with another natural, synthetic polymers and nanoparticles, and other composites materials. Overall, this review article clearly presents a summary of the recent advances in research studies on GG for different biomedical applications.

Fabrication and Characterization of Composite Meshes Loaded with Antimicrobial Peptides

Biomaterials-centered infection or implant-associated infection plays critical roles in all areas of medicine with implantable devices. The widespread over use of antibiotics has caused severe bacterial resistance and even super bugs. Therefore, the development of anti-infection implantable devices with non-antibiotic-based new antimicrobial agents is indeed a priority for all of us. In this study, antimicrobial composite meshes were fabricated with broad-spectrum antimicrobial peptides (AMPs). Macroporous polypropylene meshes with poly-caprolactone electrospun nanosheets were utilized as a substrate to load AMPs and gellan gum presented as a media to gel with AMPs. Different amounts of AMPs were loaded onto gellan gum to determine the appropriate dose. The surface morphologies, Fourier-transform infrared spectroscopy spectra, in vitro release profiles, mechanical performances, in vitro antimicrobial properties, and cytocompatibility of composite scaffolds were evaluated. Results showed that AMPs were loaded into the meshes successfully, the in vitro release of AMPs in phosphate-buffered saline was prolonged, and less than 60% peptides were released in 10 days. The mechanical properties of composite meshes were also within the scope of several commercial surgical meshes. Composite meshes with the AMP loading amount of over 3 mg/cm² showed inhibition against both Gram-negative and Gram-positive bacteria effectively, while they presented no toxicity to mammalian cells even at a loading amount of 10 mg/cm². These results demonstrate a new simple and practicable method to offer antimicrobial properties to medical devices for hernia repair.

Recent trends on gellan gum blends with natural and synthetic polymers: A review

Gellan gum (GG), a linear negatively charged exopolysaccharide,is biodegradable and non-toxic in nature. It produces hard and translucent gel in the presence of metallic ions which is stable at low pH. However, GG has poor mechanical strength, poor stability in physiological conditions, high gelling temperature and small temperature window.Therefore,it is blended with different polymers such as agar, chitosan, cellulose, sodium alginate, starch, pectin, polyanaline, pullulan, polyvinyl chloride, and xanthan gum. In this article, a comprehensive overview of combination of GG with natural and synthetic polymers/compounds and their applications in biomedical field involving drug delivery system, insulin delivery, wound healing and gene therapy, is presented. It also describes the utilization of GG based materials in food and petroleum industry. All the technical scientific issues have been addressed; highlighting the recent advancement.

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 30 min whereas IPN beads took 5 h at gastric pH and 10 h 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.

Efeito da modificação química na solubilidade e intumescimento de microesferas à base de goma do cajueiro carboximetilada e quitosana

Resumo Esferas de goma do cajueiro carboximetilada e quitosana foram produzidas via complexação polieletrolítica. As esferas foram modificadas quimicamente de modo a obter-se sistemas estáveis em meio ácido e que apresentassem uma resposta de intumescimento diferenciado frente à variação de pH. As esferas foram modificadas por reacetilação da quitosana e por reticulação com epicloridrina, glutaraldeído e genipina. As esferas reticuladas foram caracterizadas por meio de técnicas como: espectroscopia de absorção no infravermelho, análise termogravimétrica, microscopia eletrônica de varredura e quanto à solubilidade em pH 1,2 e ao intumescimento. As esferas de goma do cajueiro carboximetilada e quitosana reacetilada, e as esferas reticuladas com epicloridrina apresentaram baixa resistência à dissolução em pH 1,2. Entretanto, as esferas reticuladas com glutaraldeído e genipina apresentaram resistência à dissolução e baixo coeficiente de difusão. As esferas reticuladas com genipina apresentaram um grau de intumescimento maior do que as esferas reticuladas com glutaraldeído nas concentrações de 3% e 5% (massa/volume). As esferas reticuladas com genipina apresentaram intumescimento responsivo à variação de pH e estabilidade em pH 1,2, indicando que esses sistemas possuem potencial para uso em sistemas de liberação controlada de fármacos por via oral.