In-vitro release kinetics of cefadroxil-loaded sodium alginate interpenetrating network beads

Preparation of double-system imprinted polymer-coated multi-walled carbon nanotubes and their application in simultaneous determination of thyroid-disrupting chemicals in dust samples

Dust ingestion is a significant route of human exposure to thyroid-disrupting chemicals (TDCs), and simultaneous determination of multi-contaminants is a great challenge for environmental monitoring. In this study, molecularly imprinted polymer-coated multi-walled carbon nanotubes using thyroxine as the template were synthesized for highly selective TDCs capture. This polymer was prepared by integrating the atom transfer radical polymerization using 2-(3-indol-yl)ethylmethacrylamide as the monomer with the self-polymerization of dopamine. Construction of double-system imprinted cavities could significantly improve their selective recognition performance for TDCs and the coincidence rate reached 88.5 %. The prepared polymers were applied as the solid phase extraction adsorbent to simultaneously determine 7 groups of 35 TDCs. The proposed method showed wide linear range (0.25-1000 ng L-1), low limits of detection (0.02-0.23 ng L-1) and acceptable recoveries (81.8 %-103.5 %). The occurrence and distribution of TDCs were then studied in indoor dust samples (n = 65) collected from four cities in China. We found that tetrabromobisphenol A was the predominant compound and perfluorinated compounds were the most abundant TDCs. In addition, the distribution ratio of TDCs varied between regions. This study provides an efficient technology for direct exposure assessment of multi-contaminants.

State of Innovation in Alginate-Based Materials

This review article presents past and current alginate-based materials in each application, showing the widest range of alginate's usage and development in the past and in recent years. The first segment emphasizes the unique characteristics of alginates and their origin. The second segment sets alginates according to their application based on their features and limitations. Alginate is a polysaccharide and generally occurs as water-soluble sodium alginate. It constitutes hydrophilic and anionic polysaccharides originally extracted from natural brown algae and bacteria. Due to its promising properties, such as gelling, moisture retention, and film-forming, it can be used in environmental protection, cosmetics, medicine, tissue engineering, and the food industry. The comparison of publications with alginate-based products in the field of environmental protection, medicine, food, and cosmetics in scientific articles showed that the greatest number was assigned to the environmental field (30,767) and medicine (24,279), whereas fewer publications were available in cosmetic (5692) and food industries (24,334). Data are provided from the Google Scholar database (including abstract, title, and keywords), accessed in May 2023. In this review, various materials based on alginate are described, showing detailed information on modified composites and their possible usage. Alginate's application in water remediation and its significant value are highlighted. In this study, existing knowledge is compared, and this paper concludes with its future prospects.

Design, development and characterization of interpenetrating polymer network hydrogel bead for controlled release of glipizide drug

In the current study, a novel interpenetrating polymer network (IPN) hydrogel bead was developed by encapsulation of antidiabetic drug glipizide using sodium alginate (SAL) and xanthan gum (XAG) biopolymers by ionotropic gelation technique with calcium chloride as cross-linking agent. In light of the fact that IPN hydrogel beads posses greater benefits in controlling the release of such short acting drug, sodium alginate and xanthan gum IPN hydrogel beads were prepared at different mass ratios (SAL:XAG =10:0, 9:1, 8:2, 7:3, 6:4, 5:5). Similarly, drug-loaded IPN hydrogel beads were also developed. The prepared hydrogel beads were investigated using Fourier transform infrared spectroscopy, X-ray powder diffraction, and thermogravimetric studies to understand the type of interactions between the composite beads. Surface morphology changes were studied by scanning electron microscopy. The particle size, drug entrapment efficiency, and swelling behavior of prepared hydrogel beads were also studied. Based on In-vitro drug dissolution studies, it was observed that SXF4 preparation containing SAL and XAG polymers at 7:3 ratio showed extended drug release of 97.53% at 9 h. This study demonstrated that inclusion of XAG has extended the drug release and able to achieve zero-order drug release profile.

Computational Investigation to Design Ofloxacin-Loaded Hybridized Nanocellulose/Lipid Nanogels for Accelerated Skin Repair

The pharmaceutical application of biomaterials has attained a great success. Rapid wound healing is an important goal for many researchers. Hence, this work deals with the development of nanocellulose crystals/lipid nanogels loaded with ofloxacin (OFX) to promote skin repair while inhibiting bacterial infection. Ofloxacin-loaded hybridized nanocellulose/lipid nanogels (OFX-HNCNs) were prepared and evaluated adopting a computational method based on regression analysis. The optimized nanogels (OFX-HNCN7) showed a spherical outline with an encapsulation efficiency (EE), particle size (PS) and zeta potential (ZP) values of 97.53 ± 1.56%, 200.2 ± 6.74 nm and -26.4 ± 0.50 mV, respectively, with an extended drug release profile. DSC examination of OFX-HNCN7 proved the amorphization of the encapsulated drug into the prepared OFX-HNCNs. Microbiological studies showed the prolonged inhibition of bacterial growth by OFX-HNCN7 compared to the free drug. The cytocompatibility of OFX-HNCN7 was proved by Sulforhodamine B assay. Tissue repair was evaluated using the epidermal scratch assay based on cell migration in human skin fibroblast cell line, and the results depicted that cell treated with OFX-HNCN7 showed a faster and more efficient healing compared to the control. In overall, the obtained findings emphasize the benefits of using the eco-friendly bioactive nanocellulose, hybridized with lipid, to prepare a nanocarrier for skin repair.

Development and Characterization of Natural Product Derived Macromolecules Based Interpenetrating Polymer Network for Therapeutic Drug Targeting

Interpenetrating polymer network (IPN)-based bead formulations were exploited by cross-linking different hydrophilic polymers in different combinations and at different ratios. Polyvinyl alcohol, xanthan gum, guar gum, gellan gum, and sodium alginate (Na-alginate) were used in this work as hydrophilic polymers to enhance the solubility of diclofenac sodium and also to target the delivery at preferred locations. IPN beads based on polysaccharides were prepared by the ionic gelation method. Differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy data showed that the IPN microbeads solubilized and encapsulated the drug within the network. We found over 83% encapsulation efficiency of the drug delivery system for the drug, and this efficiency increased with the concentration of the polymer. Ex vivo experiments using the goat intestine revealed that the IPN microbeads were able to adhere to the intestinal epithelium, a mucoadhesive behavior that could be beneficial to the drug pharmacokinetics, while in vitro experiments in phosphate buffer showed that the IPN enabled significant drug release. We believe that these IPN microbeads are an excellent drug delivery system to solubilize drug molecules and ensure adhesion to the intestinal wall, thereby localizing the drug release to enhance bioavailability of poorly soluble drugs.

Development and optimization of Fe3+-crosslinked sodium alginate-methylcellulose semi-interpenetrating polymer network beads for controlled release of ibuprofen

In this study, ionically crosslinked beads of sodium alginate (NaAlg) and methylcellulose (MC) were prepared as semi-interpenetrating polymer networks (semi-IPN) in the size range of 1.97 ± 0.09-1.22 ± 0.13 mm by crosslinking with FeCl₃ and loaded with ibuprofen (IBU), which is a nonsteroidal anti-inflammatory drug. The highest 93.33% entrapment efficiency of IBU was achieved, and the drug release behaviors, mean particle size, and entrapment efficiency of beads were investigated in terms of the polymer composition, a ratio of ibuprofen to polymer, exposure time to crosslinker, and concentration of the crosslinking agent. Semi-IPN formulations prepared were also characterized using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray Diffraction (X-RD), and scanning electron microscopy (SEM). It was observed that IBU-loaded beads displayed better release performance with an increase amount of NaAlg in the structure. Finally, the optimum IBU release was obtained as 93.9% for beads containing 66.7% (w/w) NaAlg, 33.3% (w/w) MC, IBU/polymer ratio of 1/4, FeCl₃ concentration of 0.1 M, and crosslinking time of 90 min. The in vitro release rate was fitted to five empirical equations, and the diffusion exponent n, which indicated that the release mechanism of IBU from beads followed the Anomalous and Case II transport mechanism.

Micro-Nano formulation of bile-gut delivery: rheological, stability and cell survival, basal and maximum respiration studies

Probucol (PB) is a drug that exhibits significant hydrophobicity and substantial intra and inter individual variability in oral absorption, with a miniature bioavailability and complex three compartmental pharmacokinetic modelling due to its high lipid affinity, low stability and high octanol to water partition coefficient. Multiple attempts to formulate PB have not produced satisfactory stable matrices, drug-release profile or rheological flow properties for optimum manufacturing conditions, and with positive and none toxic biological effects. Lithocholic acid (LCA) has recently shown to optimise formulation and cell uptake of drugs. Hence, the aim of this study was to design new PB delivery system, using LCA, and examine its morphology, rheology, stability, and cellular effects. PB was formulated with LCA and sodium alginate (PB-LCA-SA) using various microencapsulation methodologies, and best formulation was investigated in vitro and ex vivo. Using our Ionic Gelation Vibrational Jet flow technology, PB-LCA-SA microcapsules showed good stability and significantly enhanced cell viability, cellular respiration, and reduced inflammation suggesting potential LCA applications in PB delivery and biological effects.

The Use of Chitosan, Alginate, and Pectin in the Biomedical and Food Sector-Biocompatibility, Bioadhesiveness, and Biodegradability

Nowadays, biopolymers as intelligent and active biopolymer systems in the food and pharmaceutical industry are of considerable interest in their use. With this association in view, biopolymers such as chitosan, alginate, pectin, cellulose, agarose, guar gum, agar, carrageenan, gelatin, dextran, xanthan, and other polymers have received significant attention in recent years due to their abundance and natural availability. Furthermore, their versatile properties such as non-toxicity, biocompatibility, biodegradability, and flexibility offer significant functionalities with multifunctional applications. The purpose of this review is to summarize the most compatible biopolymers such as chitosan, alginate, and pectin, which are used for application in food, biotechnological processes, and biomedical applications. Therefore, chitosan, alginate, and pectin are biopolymers (used in the food industry as a stabilizing, thickening, capsular agent, and packaging) with great potential for future developments. Moreover, this review highlights their characteristics, with a particular focus on their potential for biocompatibility, biodegradability, bioadhesiveness, and their limitations on certain factors in the human gastrointestinal tract.

Polymeric Mesoporous Silica Nanoparticles for Enhanced Delivery of 5-Fluorouracil In Vitro

There is a need for the improvement of conventional cancer treatment strategies by incorporation of targeted and non-invasive procedures aimed to reduce side-effects, drug resistance, and recurrent metastases. The anti-cancer drug, 5-fluorouracil (5-FU), is linked to a variety of induced-systemic toxicities due to its lack of specificity and potent administration regimens, necessitating the development of delivery vehicles that can enhance its therapeutic potential, while minimizing associated side-effects. Polymeric mesoporous silica nanoparticles (MSNs) have gained popularity as delivery vehicles due to their high loading capacities, biocompatibility, and good pharmacokinetics. MSNs produced in this study were functionalized with the biocompatible polymers, chitosan, and poly(ethylene)glycol to produce monodisperse NPs of 36-65 nm, with a large surface area of 710.36 m2/g, large pore volume, diameter spanning 9.8 nm, and a favorable zeta potential allowing for stability and enhanced uptake of 5-FU. Significant drug loading (0.15-0.18 mg5FU/mgmsn), controlled release profiles (15-65%) over 72 hours, and cell specific cytotoxicity in cancer cells (Caco-2, MCF-7, and HeLa) with reduced cell viability (≥50%) over the non-cancer (HEK293) cells were established. Overall, these 5FU-MSN formulations have been shown to be safe and effective delivery systems in vitro, with potential for in vivo applications.

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.

Tailor made alginate hydrogel for local infection prophylaxis in orthopedic applications

Preventing implants associated infections is crucial in orthopedics. Local delivery of antibiotics through implants is a promising strategy to solve this issue. In this study, alginate is tailored to control its swelling, entrapment and release of ciprofloxacin (antibiotic) through the formation of interpenetrating polymer network and composite matrices using gelatin and hydroxyapatite. Developed matrices were characterized by Fourier transform infrared spectroscopy, x-ray diffraction and scanning electron microscopy. The individual tailoring approaches exerted significant influence on the swelling behavior of alginate matrix consequently enhanced the drug entrapment and extended the release period. However, the alginate matrix tailored with the combined approaches resulted in a superior matrix, which had a better control over the burst release of ciprofloxacin. Drug release prolonged from 5h to 240h for composite matrix as compared with alginate matrix showing that alginate combined with gelatin and hydroxyapatite sustained the release for longer periods. This matrix revealed excellent biocompatibility with osteoblast like MG-63 cell lines and showed good antibacterial activity against S. aureus and E. coli.

pH-Responsive carriers for oral drug delivery: challenges and opportunities of current platforms

Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines. This review provides a wide perspective on current status of pH-responsive oral drug delivery systems prepared mainly with organic polymers or inorganic materials, including the strategies used to overcome GI barriers, the challenges in their development and future prospects, with focus on technology trends to improve the bioavailability of orally delivered drugs, the mechanisms of drug release from pH-responsive oral formulations, and their application for drug delivery, such as protein and peptide therapeutics, vaccination, inflammatory bowel disease (IBD) and bacterial infections.

Physicochemical Properties and the Gelation Process of Supramolecular Hydrogels: A Review

Supramolecular polysaccharide-based hydrogels have attracted considerable research interest recently due to their high structural functionality, low toxicity, and potential applications in foods, cosmetics, catalysis, drug delivery, tissue engineering and the environment. Modulation of the stability of hydrogels is of paramount importance, especially in the case of stimuli-responsive systems. This review will update the recent progress related to the rational design of supramolecular hydrogels with the objective of understanding the gelation process and improving their physical gelation properties for tailored applications. Emphasis will be given to supramolecular host⁻guest systems with reference to conventional gels in describing general aspects of gel formation. A brief account of the structural characterization of various supramolecular hydrogels is also provided in order to gain a better understanding of the design of such materials relevant to the nature of the intermolecular interactions, thermodynamic properties of the gelation process, and the critical concentration values of the precursors and the solvent components. This mini-review contributes to greater knowledge of the rational design of supramolecular hydrogels with tailored applications in diverse fields ranging from the environment to biomedicine.

Interpenetrating hydrogels of O-carboxymethyl Tamarind gum and alginate for monitoring delivery of acyclovir

In this work, an interpenetrating hydrogel network was constructed using varying combination of O-carboxymethyl Tamarind gum (CTG) and alginate by Ca⁺² ion induced gelation method. The hydrogels were characterized by FTIR spectroscopy, Field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and differential scanning calorimetry (DSC) analyses. The hydrogels were spherical in shape with rough surface textures. Depending on the alginate: CTG mass ratio, the hydrogel particles entrapped a maximum of ∼70% acyclovir. The drug release from interpenetrating hydrogels was 18-23% in HCl solution (pH1.2) in 2h. The drug release became faster in phosphate buffer solution (pH6.8) as the proportion of CTG was increased from 25% to 50%. However, the drug release was still slower than that observed for hydrogel particles of sodium alginate alone. Overall, the drug release tendency of the particles was higher in phosphate buffer solution than that in HCl solution. The non-Fickian drug release behavior was assumed after fitting the drug release data into Korsmeyer-Peppas model. The drug release was found to control by diffusion and swelling kinetics of the hydrogels. Thus, CTG gum could effectively retard drug release when used in combination with sodium alginate at an optimized mass ratio.

Comparative bio-safety and in vivo evaluation of native or modified locust bean gum-PVA IPN microspheres

Strategically developed natural polymer-based controlled release multiparticulate drug delivery systems have gained special interest for “spatial placement” and “temporal delivery” of drug molecules. In our earlier study, locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (LBG-PVA IPN), carboxymethylated locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (CMLBG-PVA IPN) and acrylamide grafted locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (Am-g-LBG-PVA IPN) were prepared and characterized. The present study deals with accelerating stability testing, comparative bio-safety and single dose in vivo pharmacokinetic study of all three IPN microspheres for controlled oral delivery of buflomedil hydrochloride (BH). From the stability study, it was observed that the particles were stable throughout the study period. From toxicity and biodegradability study it was proved that the microspheres were safe for internal use and complied with bio-safety criterion. From the in vivo pharmacokinetic study in rabbits, it was observed that the CMLBG-PVA IPN microspheres possessed almost similar Tmax value with BH oral suspension. However, in comparison between the LBG-PVA and Am-g-LBG-PVA IPN microspheres, the later showed well controlled release property than the first in biological condition. Thus, this type of delivery system might be useful to achieve the lofty goals of the controlled release drug delivery.

Novel chenodeoxycholic acid-sodium alginate matrix in the microencapsulation of the potential antidiabetic drug, probucol. An in vitro study

CONTEXT

We previously designed, developed and characterized a novel microencapsulated formulation as a platform for the targeted delivery of Probucol (PB) in an animal model of Type 2 Diabetes.

OBJECTIVE

The objective of this study is to optimize this platform by incorporating Chenodeoxycholic acid (CDCA), a bile acid with good permeation-enhancing properties, and examine its effect in vitro. Using sodium alginate (SA), we prepared PB-SA (control) and PB-CDCA-SA (test) microcapsules.

RESULTS AND DISCUSSION

CDCA resulted in better structural and surface characteristics, uniform morphology, and stable chemical and thermal profiles, while size and rheological parameters remained unchanged. PB-CDCA-SA microcapsules showed good excipients' compatibilities, as evidenced by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy studies. CDCA reduced microcapsule swelling at pH 7.8 at both 37 °C and 25 °C and improved PB-release.

CONCLUSION

CDCA improved the characteristics and release properties of PB-microcapsules and may have potential in the targeted oral delivery of PB.

Development of mucoadhesive microbeads using thiolated sodium alginate for intrapocket delivery of resveratrol

Resveratrol (Res), a polyphenolic phytoalexin, had shown a promising therapeutic efficacy towards treatment of periodontal disease in vitro. This work aims to develop Res microbeads with strong mucoadhesion using thiolated alginate (TA) for local treatment of periodontal pockets. TA was synthesized by conjugating sodium alginate (A) with thioglycolic acid. Product was evaluated by IR and DSC. Both A and A:TA Res microbeads with different ratios were prepared by ionotropic gelation method. Formulations were evaluated regarding their entrapment efficiency (%EE), swelling index (SI), in vitro drug release and kinetics. Selected formula was examined for its mucoadhesion by ex vivo wash-off method, surface morphology using scanning electron microscope (SEM) and stability against light. Clinical evaluation is running.Formation of TA was confirmed. %EE for all formulations ranged from 83.72 to 104.54%. Results revealed a significant lower SI for TA rich formulation (A/TA 1:1) along with slower release rate and zero-order kinetics, in addition to powerful mucoadhesion; 26% remaining of microbeads after 1h, compared to 2% for A microbeads. SEM micrographs showed a rough surface with drug precipitation. The formula maintained its %EE after 5h exposure to direct sunlight. A/TA 1:1 mucoadhesive Res microbeads could be exploited as a prolonged drug release devices for intrapocket application.

Encapsulation of sorbitan ester-based organogels in alginate microparticles

Leaching of the internal apolar phase from the biopolymeric microparticles during storage is a great concern as it undoes the beneficial effects of encapsulation. In this paper, a novel formulation was prepared by encapsulating the sunflower oil-based organogels in alginate microparticles. Salicylic acid and metronidazole were used as the model drugs. The microparticles were prepared by double emulsion methodology. Physico-chemical characterization of the microparticles was done by microscopy, FTIR, XRD, and DSC studies. Oil leaching studies, biocompatibility, mucoadhesivity, in vitro drug release, and the antimicrobial efficiency of the microparticles were also performed. The microparticles were found to be spherical in shape. Gelation of the sunflower oil prevented leaching of the internal phase from the microparticles. Release of drugs from the microparticles followed Fickian kinetics and non-Fickian kinetics in gastric and intestinal environments, respectively. Microparticles showed good antimicrobial activity against both Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria. The results suggested that the developed formulations hold promise to carry oils without leakage of the internal phase. Encapsulation of organogels within the microparticles has improved the drug entrapment efficiency and improved characteristics for controlled delivery applications.

An optimized probucol microencapsulated formulation integrating a secondary bile acid (deoxycholic acid) as a permeation enhancer

The authors have previously designed, developed, and characterized a novel microencapsulated formulation as a platform for the targeted delivery of therapeutics in an animal model of type 2 diabetes, using the drug probucol (PB). The aim of this study was to optimize PB microcapsules by incorporating the bile acid deoxycholic acid (DCA), which has good permeation-enhancing properties, and to examine its effect on microcapsules' morphology, rheology, structural and surface characteristics, and excipients' chemical and thermal compatibilities. Microencapsulation was carried out using a BÜCHI-based microencapsulating system established in the authors' laboratory. Using the polymer sodium alginate (SA), two microencapsulated formulations were prepared: PB-SA (control) and PB-DCA-SA (test) at a constant ratio (1:30 and 1:3:30, respectively). Complete characterization of the microcapsules was carried out. The incorporation of DCA resulted in better structural and surface characteristics, uniform morphology, and stable chemical and thermal profiles, while size and rheological parameters remained similar to control. In addition, PB-DCA-SA microcapsules showed good excipients' compatibilities, which were supported by data from differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray studies, suggesting microcapsule stability. Hence, PB-DCA-SA microcapsules have good rheological and compatibility characteristics and may be suitable for the oral delivery of PB in type 2 diabetes.

Novel artificial cell microencapsulation of a complex gliclazide-deoxycholic bile acid formulation: a characterization study

Gliclazide (G) is an antidiabetic drug commonly used in type 2 diabetes. It has extrapancreatic hypoglycemic effects, which makes it a good candidate in type 1 diabetes (T1D). In previous studies, we have shown that a gliclazide-bile acid mixture exerted a hypoglycemic effect in a rat model of T1D. We have also shown that a gliclazide-deoxycholic acid (G-DCA) mixture resulted in better G permeation in vivo, but did not produce a hypoglycemic effect. In this study, we aimed to develop a novel microencapsulated formulation of G-DCA with uniform structure, which has the potential to enhance G pharmacokinetic and pharmacodynamic effects in our rat model of T1D. We also aimed to examine the effect that DCA will have when formulated with our new G microcapsules, in terms of morphology, structure, and excipients' compatibility. Microencapsulation was carried out using the Büchi-based microencapsulating system developed in our laboratory. Using sodium alginate (SA) polymer, both formulations were prepared: G-SA (control) at a ratio of 1:30, and G-DCA-SA (test) at a ratio of 1:3:30. Complete characterization of microcapsules was carried out. The new G-DCA-SA formulation was further optimized by the addition of DCA, exhibiting pseudoplastic-thixotropic rheological characteristics. The size of microcapsules remained similar after DCA addition, and these microcapsules showed no chemical interactions between the excipients. This was supported further by the spectral and microscopy studies, suggesting microcapsule stability. The new microencapsulated formulation has good structural properties and may be useful for the oral delivery of G in T1D.

Locust bean gum in the development of sustained release mucoadhesive macromolecules of aceclofenac

The study shows the development and optimization of locust bean gum (LBG)-alginate mucoadhesive macromolecules containing aceclofenac through ionotropic-gelation using 3(2) factorial design. The effect of amount of LBG and sodium alginate on drug entrapment efficiency (%DEE), % mucoadhesion at 8h (M8) and % in vitro drug release at 10h (%Q10h) were optimized. The percentage yield, average size and DEE of macromolecules were found within the range of 93.19 to 96.65%, 1.328 ± 0.11 to 1.428 ± 0.13 μm, and 56.37 to 68.54%, respectively. The macromolecules were also characterized by SEM, FTIR and DSC. The in vitro drug release from these macromolecules (84.95 ± 2.02 to 95.33 ± 1.56% at 10h) exhibited sustained release (first-order) pattern with super case-II transport mechanism. The swelling and mucoadhesivity of these macromolecules were affected by pH of the medium. The design established the role of derived polynomial equations and plots in predicting the values of dependent variables for the preparation and optimization.

A novel vaginal drug delivery system: anti-HIV bioadhesive film containing abacavir

Women are very much susceptible for acquired immunodeficiency syndrome (AIDS) and other sexually transmitted diseases (STDs), mainly due to unprotected heterosexual vaginal intercourse and for some other social and economical disadvantages. Our aim was to formulate and optimize vaginal film of abacavir, a potent nucleoside reverse transcriptase inhibitor, for the treatment of AIDS and HIV. Abacavir films were prepared by solvent evaporation method using sodium alginate (Na-alginate) as the main polymer, Hydroxypropyl Methylcellulose E 15 (HPMC E 15) as the copolymer and glycerol as a humectant. Abacavir sulphate (ABC) was used here as a drug. Films were optimized for various physicochemical parameters such as tensile strength, % elongation at break, swelling capacity, drug content (mg/cm(2)), thickness, folding endurance, bioadhesion, pH, moisture content and SEM. Drug polymer interaction was studied by FTIR Spectra. The drug release study was accomplished in dissolution apparatus. In vivo study was also carried out. This newly formed film was one kind of sustain release type and can be considered as a novel drug carrier system for the treatment of AIDS and other STDs. It was suitable for local as well as systemic effect. The films showed good physicochemical property with good aesthetic appeal.

Therapeutic applications of hydrogels in oral drug delivery

INTRODUCTION

Oral delivery of therapeutics, particularly protein-based pharmaceutics, is of great interest for safe and controlled drug delivery for patients. Hydrogels offer excellent potential as oral therapeutic systems due to inherent biocompatibility, diversity of both natural and synthetic material options and tunable properties. In particular, stimuli-responsive hydrogels exploit physiological changes along the intestinal tract to achieve site-specific, controlled release of protein, peptide and chemotherapeutic molecules for both local and systemic treatment applications.

AREAS COVERED

This review provides a wide perspective on the therapeutic use of hydrogels in oral delivery systems. General features and advantages of hydrogels are addressed, with more considerable focus on stimuli-responsive systems that respond to pH or enzymatic changes in the gastrointestinal environment to achieve controlled drug release. Specific examples of therapeutics are given. Last, in vitro and in vivo methods to evaluate hydrogel performance are discussed.

EXPERT OPINION

Hydrogels are excellent candidates for oral drug delivery, due to the number of adaptable parameters that enable controlled delivery of diverse therapeutic molecules. However, further work is required to more accurately simulate physiological conditions and enhance performance, which is important to achieve improved bioavailability and increase commercial interest.

Alginate Particles as Platform for Drug Delivery by the Oral Route: State-of-the-Art

Pharmaceutical research and development aims to design products with ensured safety, quality, and efficacy to treat disease. To make the process more rational, coherent, efficient, and cost-effective, the field of Pharmaceutical Materials Science has emerged as the systematic study of the physicochemical properties and behavior of materials of pharmaceutical interest in relation to product performance. The oral route is the most patient preferred for drug administration. The presence of a mucus layer that covers the entire gastrointestinal tract has been exploited to expand the use of the oral route by developing a mucoadhesive drug delivery system that showed a prolonged residence time. Alginic acid and sodium and potassium alginates have emerged as one of the most extensively explored mucoadhesive biomaterials owing to very good cytocompatibility and biocompatibility, biodegradation, sol-gel transition properties, and chemical versatility that make possible further modifications to tailor their properties. The present review overviews the most relevant applications of alginate microparticles and nanoparticles for drug administration by the oral route and discusses the perspectives of this biomaterial in the future.

Designing improved poly lactic-co-glycolic acid microspheres for a malarial vaccine: incorporation of alginate and polyinosinic-polycytidilic acid

Vaccination using proteins and peptides is currently gaining importance. One of the major drawbacks of this approach is the lack of an efficient immune response when the antigens are administered without adjuvants. In this study, we have taken the advantage of a combined adjuvant system in order to improve the immunogenicity of the SPf66 malarial antigen. For that purpose, we have combined poly (lactic-co-glycolic) acid microspheres, alginate, and polyinosinic polycytidilic acid. Our results show that microspheres can enhance the IgG production obtained with Freund's complete adjuvant. We have attributed this improvement to the presence of polyinosinic polycytidilic acid, since formulations comprising this adjuvant overcame the immune response from the others. In addition, our microspheres produced both IgG1 and IgG2a, leading to mixed Th1/Th2 activation, optimal for malaria vaccination. In conclusion, we have designed a preliminary formulation with a high potential for the treatment of malaria.