Controlled Drug Delivery Systems Research Articles

Design, Development and in vitro Evaluation of Hydrogels Prepared by Free Radical Polymerization of Acrylic Acid (AAc) Containing a Model Antidiabetic Drug

Abstract: Introduction: The controlled release of medicaments in the management of diabetes is desirable to have a better therapeutic activity of the drug. Objectives: In the present study hydrogels were prepared as a controlled drug delivery system taking Rosiglitazone as a model drug. Materials and Methods: Hydrogels were created using the Free Radical Polymerization approach, with the crosslinker N, N′-Methylene bisacrylamide serving as a binding agent for the polymerization. To create a polymeric network, ammonium persulphate has been used as a polymerization inducer for AAc to poly (acrylic acid) in the existence of polyvinyl alcohol (PVP). A maximum of fifteen formulations were created with various concentrations of polymers and crosslinking agents to test the swelling, diffusion coefficients, ESR, and in vitro drug release properties of the drugs tested. The FT-IR and DSC techniques were used to determine the drug's compatibility with the polymers. The XRD studies were carried out to understand the nature of the drug contained within the hydrogel formulation. The morphologies of the surface were determined using SEM. Results and Discussion: A greater swelling was observed in the basic pH range and a marginal swelling was observed in the acidic pH range according to the swelling studies. The ESR affirmed that the pH of the hydrogels was indeed a factor in the swelling of the gels. The results of the diffusion study revealed that the diffusion coefficient has risen as a result of the reduction in cross-linker concentration and the increase in acrylic acid concentration in the solution. The in vitro release of drug data revealed that the swelling has been increased as a result of the increased concentration of acrylic acid, which resulted in the increased release of the drug. However, when the concentrations of PVP and cross-linker were increased, it was discovered that the drug release was decreased. Conclusion: AAc-PVP based hydrogel was found to be a promising controlled drug delivery system for the treatment of Rosiglitazone, according to the findings of this study. Keywords: Hydrogels, PVP Acrylic acid, Free Radical Polymerization, Antidiabetic Drug.

Articulation and Evaluation of Extended-Release Beads using a Sulfasalazine Drug

The present study was focused on optimization of the formulation for the extended-release capsule of mesalamine. Multi particulate system has long been employed to improve the bioavailability of drugs. Mesalamine pellets were prepared by Coating drug solution on sugar sphere followed by functional coating. The release pattern depends upon the pore formation on the outer surface of the unit particle or beads and then slowly and steadily releasing drugs from the inner core. Ethocel grade 7cps was used as a release controlling polymer with the aid of hydrophilic polymer HPMC E5 with pore former to work as a controlled drug delivery system. The functional coated Pellets were used for various parameters like assay and in-vitro dissolution profile. The study confirmed that mesalamine can deliver its effect into lower part of intestine. The finally prepared pellets were used for the treatment of IBD (Ulcerative colitis) Batch 2 had gave optimised result which follow the US specification. Kinetics was applied to the optimized Batch B-2 which was following Higuchi matrix and the mechanism of release was diffusion as the polymer used was HPMC E5 and Tri ethyl citrate –pore former and Ethocel- impenetrable barrier.

Model-based optimization of drug release rate from a size distributed population of biodegradable polymer carriers

In the present study, a comprehensive polymer degradation-drug diffusion model is developed to describe the polymer degradation kinetics and quantify the release rate of an active pharmaceutical ingredient (API) from a size-distributed population of drug-loaded poly(lactic-co-glycolic) acid (PLGA) carriers in terms of material and morphological properties of the drug carriers. To take into account the spatial–temporal variation of the drug and water diffusion coefficients, three new correlations are developed in terms of spatial–temporal variation of the molecular weight of the degrading polymer chains. The first one relates the diffusion coefficients with the time-spatial variation of the molecular weight of PLGA and initial drug loading and, the second one with the initial particle size, and the third one with evolution of the particle porosity due to polymer degradation. The derived model, comprising a system of partial differential and algebraic equations, is numerically solved using the method of lines and validated against published experimental data on the drug release rate from a size distributed population of piroxicam-PLGA microspheres. Finally, a multi-parametric optimization problem is formulated to calculate the optimal particle size and drug loading distributions of drug-loaded PLGA carriers to realize a desired zero-order drug release rate of a therapeutic drug over a specified administration period of several weeks. It is envisaged that the proposed model-based optimization approach will aid the optimal design of new controlled drug delivery systems and, consequently, the therapeutic outcome of an administered drug.

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.

Peripheral Regional Anesthesia Using Local Anesthetics: Old Wine in New Bottles?

During the past decade, numerous efforts were undertaken aiming at prolonging the analgesic effect of regional anesthesia. With the development of extended-release formulations and enhanced selectivity for nociceptive sensory neurons, a very promising contribution to the development of pain medications has been achieved. At present, liposomal bupivacaine is the most popular, non-opioid, controlled drug delivery system, but its duration of action, which is still controversially discussed, and its expensiveness have decreased initial enthusiasm. Continuous techniques can be seen as an elegant alternative for providing a prolonged duration of analgesia, but for logistic or anatomical reasons, they are not always the best choice. Therefore, focus has been directed towards the perineural and/or intravenous addition of old and established substances. As for perineural application, most of these so-called 'adjuvants' are used outside their indication, and their pharmacological efficacy is often not or only poorly understood. This review aims to summarize the recent developments for prolonging the duration of regional anesthesia. It will also discuss the potential harmful interactions and side effects of frequently used analgesic mixtures.

Facile preparation of pH-sensitive biocompatible alginate beads havening layered double hydroxide supported metal-organic framework for controlled release from doxorubicin to breast cancer cells

In the present study, a pH-sensitive controlled drug delivery system was prepared from alginate beads impregnated with AlCu layered double hydroxides (LDH) supported copper metal-organic framework (Alg-DOX-Cu MOF-LDH beads) for controlled release from doxorubicin (DOX) to breast cancer cells. The physicochemical properties of Alg-DOX-Cu MOF-LDH beads were determined by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), field emission scanning electron microscopy (FE-SEM), and Zeta potential. The in vitro release studies showed that the Alg-DOX-Cu MOF-LDH beads had more controlled drug release than the DOX-Cu MOF-LDH and in vitro release of DOX from both carriers showed pH-response release behavior. The kinetic adsorption studies also confirmed that the drug release from the DOX-Cu MOF-LDH and Alg-DOX-Cu MOF-LDH beads well obey the Korsmeyer-Peppas model. Meanwhile, in vitro cytotoxicity and DAPI tests on L929 (non-cancerous cells) and MCF-7 (human breast cancer cells) clearly showed that the prepared AlCu LDH and Cu MOF-LDH systems had good biocompatibility. Whereas, Alg-DOX-Cu MOF-LDH beads had higher cytotoxicity effects as a result of the controlled release of DOX to MCF-7 cells. These results suggested that the Alg-DOX-Cu MOF-LDH beads can be used as an excellent drug delivery system for cancer therapy and other biomedical applications.

“FORMULATION AND EVALUATION OF TRANSDERMAL PATCH OF AMLODIPIN BESYLATE”

A Transdermal patch is a medicated adhesive patch that is placed on the skin to deliver a distinct dose of medication through the skin and into the blood stream. The transdermal drug delivery system is one of novel drug delivery system which overcomes arise from the traditional dosage form. The preformulation studies involves description, solubility, melting point of the drug were found to be comparable with the standard. Based on the preformulation studies the drug was suitable for making the transdermal formulation. In this transdermal drug delivery system F5 was having greater % drug release. The formulation F5 shows better extended release up to 24hrs when compared to other formulations. So it was concluded that the formulation F5 prepared by using Eudragit RS100 and HPMC is the better formulation for control release of drug up to 24hrs of time. However, the best formulation F-5 follows first order kinetics and the mechanism of diffusion. Results of the present study encouraged that it can be used as controlled drug delivery system and frequency of administration can be minimized.

Controlled drug delivery systems for improved efficacy and bioavailability of flavonoids

In past decades, experiments have been done to find the properties of plant polyphenols and their protective role in various diseases. In the present study, a brief review has been done on flavonoids protective role in different diseases and controlled drug delivery systems that can be feasible for improving flavonoids bioavailability as well as their efficacy in the biological system.Keywords searched in PubMed, and Google Scholar are Flavones and cardiovascular diseases, flavones and neurodegenerative diseases, isoflavones and neurodegenerative diseases, Flavonoids and ageing, Flavonoids and diseases, total flavonoid content in vegetables, total flavonoid content in fruits, controlled drug delivery system and flavonoids and the significant recent articles are selected for writing this review.Flavonoids are active components present in plant products that have been found to exert several health benefits, especially in retarding the deleterious effects of CVD, cancer, ageing, diabetes, and neurodegenerative diseases. The different clinical studies have also supported the above notions, and in this commentary, we have highlighted some important findings in the field of flavonoid research. Even though it has various bioactive efficacy, most flavonoids have less bioavailability, requiring controlled drug delivery methods that can also improve flavonoids' bioavailability and stability. pH-, electro-, infrared radiation-, redox- responsive methods of controlled drug release systems are some of the valuable techniques for improving the rate of drug release and bioavailability at the targeted site.Research is warranted in this field for improving and developing various materials that can be utilized in the formation of scaffolds/polymers that improves drug loading and controlled drug release properties at the targeted site.This review will help the readers to design new strategies in flavonoid research with the help of controlled drug release methods for increased bioavailability and rate of drug release/ controlled drug release.

Synthesis of biodegradable antimicrobial pH-sensitive silver nanocomposites reliant on chitosan and carrageenan derivatives for 5-fluorouracil drug delivery toward HCT116 cancer cells

The current research relies on a one-pot green biosynthesis of silver nanoparticles (SNPs) with various ratios of silver (Ag) in the existence of N, N, N-trimethyl chitosan chloride (TMC) and carboxymethyl kappa-carrageenan (CMKC), to investigate the effectiveness of the synthesized silver nanocomposites (SNCs) as pH sensitive biodegradable carrier for orally intestinal delivery of 5-fluorouracil (5-FU) drug. FTIR, XRD, TEM and FE-SEM/EDX methods were utilized to demonstrate the structure of the prepared polyelectrolyte complex PEC (TMC/CMKC) and SNCs (TMC/CMKC/Ag). The results showed that the 5-FU encapsulation effectiveness inside all of the prepared SNCs samples was improved by increasing the concentration of Ag, reaching 92.16 ± 0.57 % with 3 % Ag. In vitro release behavior of 5-FU loaded SNC 3 % (TMC/CMKC/Ag 3 %), displayed slow and sustained release reaching 96.3 ± 0.81 % up to 24 h into pH 7.4 medium. The successful release of 5-FU from the loaded SNC 3 % was confirmed through occurrence of strong cytotoxicity, with an IC50 value of 31.15 μg/ml, and high % of apoptotic cells (30.66 %) within the treated HCT116 cells. Besides, SNC 3 % showed good biodegradability and antimicrobial properties against different bacterial strains. Overall, SNC 3 % can be suggested as an effective system for both controlled drug delivery and antibacterial action.

Electro-stimulated drug release by methacrylated hyaluronic acid-based conductive hydrogel with enhanced mechanical properties

Recently, the design of stimuli-responsive hydrogels for controlled drug delivery systems has been extensively investigated to meet therapeutic needs and optimize the release pattern of the drug. Being a natural polyelectrolyte, hyaluronic acid (HA) is excellent potential to generate new opportunities for electro-responsive drug carrier applications. In the current study, HA-based electroconductive hydrogel was developed as a novel smart drug carrier for anti-inflammatory drug release by the combination of in-situ and post polymerization mechanisms. HA was modified through methacrylation reaction to introduce photocrosslinkable groups into its structure and then reduced graphene oxide (rGO) was encapsulated into methacrylated HA (HA/MA) hydrogel by using the photopolymerization technique. In the post polymerization process, polyaniline (PANI) was incorporated/loaded into HA/MA-rGO polymeric network produced in previous step. The produced HA/MA-rGO-PANI hydrogel exhibited sufficient electrical conductivity providing the desirable electro-responsive ability for Ibuprofen (IBU) release. Furthermore, it has superior mechanical performance compared to pure (HA/MA) and rGO containing (HA/MA-rGO) hydrogels. IBU release from the hydrogel was successfully triggered by electrical stimulation and the cumulative drug release also enhanced by increasing of the applied voltage. These results highlighted that the novel HA/MA-rGO-PANI hydrogel could be a promising candidate for electrical-stimulated anti-inflammatory release systems in neural implant applications.

Stimuli-responsive injectable chitosan-based hydrogels for controlled drug delivery systems.

In the last decade, injectable hydrogels have attracted a lot of attention due to their excellent functional properties in the field of drug delivery for precise, non-invasive and focused tissue locations. Therefore, designing drug delivery systems (DDS) responsive to hydrogel stimuli to release a drug to an external stimulus with various advantages, can be very challenging. Due to their biocompatibility, mucosal adhesion, and hemostatic activity, chitosan (Chitosan)-based hydrogels offer a lot of potential for tissue engineering and drug delivery. It can be difficult to manage the structure of these stimuli-responsive CS hydrogels or they may require additional crosslinking agents, such as hydrogels with dual pH and thermo-responsiveness. Therefore, it is crucial to create these hydrogels for medicinal applications.

Hyaluronic acid-coated gold nanoparticles as a controlled drug delivery system for poorly water-soluble drugs.

Hyaluronic acid (HA) is a natural linear polysaccharide which has been widely used in cosmetics and pharmaceuticals including drug delivery systems because of its excellent biocompatibility. In this study, we investigated the one-pot synthesis of HA-coated gold nanoparticles (AuNP-HA) as a drug delivery carrier. The HAs with different molecular weights were produced by e-beam irradiation and employed as coating materials for AuNPs. Sulfasalazine (SSZ), a poorly water-soluble drug, was used to demonstrate the efficiency of drug delivery and the controlled release behaviour of the AuNP-HA. As the molecular weight of the HA decreased, the drug encapsulation efficiency of the SSZ increased up to 94%, while drug loading capacity of the SSZ was maintained at the level of about 70%. The prepared AuNP-HA-SSZ exhibited slow release of the SSZ over a short time and excellent sensitivity to different pHs and physiological conditions. The SSZ release rate was the lowest in simulated gastric conditions and the highest in simulated intestinal conditions. In this case, the AuNP-HA protects the SSZ from release under the acidic pH conditions in the stomach; on the other hand, the drug release was facilitated in the basic environment of the small intestine and colon. The SSZ was released under simulated intestinal conditions through anomalous drug transport and followed the Korsmeyer-Peppas model. Therefore, this study suggests that AuNP-HA is a promising orally-administered and intestine-targeted drug delivery system with controlled release characteristics.

A REVIEW ON NANOSPONGES AND POLYMERS USED IN THEIR PRODUCTION

Nanosponges are a novel targeted drug delivery technology. Nanosponges are cross-linked polymers that are nanostructured within a threedimensional network. They are mainly used as controlled drug delivery systems for pharmaceutical applications. In cancer applications, these nanosponges complexes are drug-loaded and release targeting peptides that are tightly bound to the radiation-induced cell surface layer of tumour receptors. Upon contact, the nanosponges adhere to the surface of tumour cells and begin to release drug molecules. Nanosponges also have the potential for the treatment of SARS-CoV-2. Such nanosponges are derived from membranes of human cells/tissues that are naturally attacked by SARS-CoV-2. These nanosponges can bind and destroy viruses and induce clinical improvement through cytokine neutralization. Thus nanosponges can successfully protect hosts from any kind of invading cells

Chitosan-vancomycin hydrogel incorporated bone repair scaffold based on staggered orthogonal structure: a viable dually controlled drug delivery system.

In clinical practice, challenges remain in the treatment of large infected bone defects. Bone tissue engineering scaffolds with good mechanical properties and antibiotic-controlled release are powerful strategies for infection treatment. In this study, we prepared polylactic acid (PLA)/nano-hydroxyapatite (nHA) scaffolds with vertical orthogonal and staggered orthogonal structures by applying 3D printing technology. In addition, vancomycin (Van)-based chitosan (CS) hydrogel (Gel@Van) was loaded on the scaffold (PLA/nHA/CS-Van) to form a local antibiotic release system. The microstructure of the composite scaffold had high porosity with interconnected three-dimensional networks. The mechanical properties of the PLA/nHA/CS-Van composite scaffold were enhanced by the addition of CS-Van. The results of the water contact angle analysis showed that the hydrophilicity of the drug-loaded scaffold improved. In addition, the composite scaffold could produce sustained release in vitro for more than 8 weeks without adverse effects on the proliferation and differentiation of mouse embryonic osteoblasts (MC3T3-E1), which confirmed its good biocompatibility. During the in vitro antimicrobial study, the composite scaffold effectively inhibited the growth of Staphylococcus aureus (S. aureus). Therefore, our results suggest that the PLA/nHA/CS-Van composite scaffold is a promising strategy for treating infected bone defects.

Modified Caffeine Release System and Its Immunomodulatory Effects on Breast Tumor Cells and Blood Phagocytes

Caffeine is an alkaloid present in a wide variety of plants. Currently the most consumed psychostimulant worldwide, its consumption is associated with several health benefits, including modulation of the innate and adaptive immune response, reduction of oxidative cellular stress, and decreased incidence of some cancers, including breast cancer. Breast cancer is the most common cause of cancer among women and the second leading cause of cancer death in women worldwide. The interaction between biomaterials and drugs has enabled a great advance in science for developing controlled drug delivery systems and has been used to treat numerous pathologies. This work aimed to evaluate the immunomodulatory effects of caffeine associated or not with polyethylene glycol adsorbed in microemulsion (MLP) on MCF-7 cells, phagocytic cells (MN), and coculture. For biological assays, ATCC (American Type Culture Collection, USA) cell lines of breast adenocarcinoma (MCF-7) and phagocytes (MN) obtained from voluntary donors were used. The cells (MN and MCF-7) and coculture were treated with caffeine and MLP and incubated for rheological characterization analyses: flow curve and viscosity, oxidative stress: superoxide anion assay (), and activity of the enzyme superoxide dismutase (Cu-Zn-SOD). Caffeine and MLP increased viscosity and blood and MCF-7 cells and affected the immunomodulation of oxidative stress metabolism of MN and MCF-7 cells treated with caffeine and associated caffeine to the MLP. These data suggest that caffeine is associated or not with MLP-induced immunomodulatory effects on MN phagocytes and MCF-7 cells, demonstrating the antitumor activity via oxidative stress and can be a complementary alternative for treating breast cancer.

Engineering dual-stimuli responsive poly(vinyl alcohol) nanofibrous membranes for cancer treatment by magnetic hyperthermia

The development of new cancer treatment options, such as multifunctional devices, allows for a more personalized treatment, avoiding the known severe side effects of conventional options. In this context, on-demand drug delivery systems can actively control the rate of drug release offering a precise control of treatment. Magnetically and thermally controlled drug delivery systems have been explored as on-demand devices to treat chronic diseases and cancer tumors. In the present work, dual-stimuli responsive systems were developed by incorporating Fe3O4 magnetic nanoparticles (NPs) and poly(N-isopropylacrylamide) (PNIPAAm) microgels into electrospun polymeric fibers for application in cancer treatment. First, Fe3O4 NPs with an average diameter of 8 nm were synthesized by chemical precipitation technique and stabilized with dimercaptosuccinic acid (DMSA) or oleic acid (OA). PNIPAAm microgels were synthesized by surfactant-free emulsion polymerization (SFEP). Poly(vinyl alcohol) (PVA) was used as a fiber template originating fibers with an average diameter of 179 ± 14 nm. Stress tests of the membranes showed that incorporating both microgels and Fe3O4 NPs in electrospun fibers increases their Young's modulus. Swelling assays indicate that PVA membranes have a swelling ratio of around 3.4 (g/g) and that the presence of microgels does not affect its swelling ability. However, with the incorporation of Fe3O4 NPs, the swelling ratio of the membranes decreases. Magnetic hyperthermia assays show that a higher concentration of NPs leads to a higher heating ability. The composite membrane with the most promising results is the one incorporated with DMSA-coated NPs, since it shows the highest temperature variation, 5.1 °C. To assess the membranes biocompatibility and ability to promote cell proliferation, indirect and direct contact cell viability assays were performed, as well as cell adhesion assays. Following an extract method viability assay, all membrane designs did not reveal cytotoxic effects on dermal fibroblasts and melanoma cancer cells, after 48 h exposure and support long-term viability. The present work demonstrates the potential of dual-stimuli composite membranes for magnetic hyperthermia and may in the future be used as an alternative cancer treatment particularly in anatomically reachable solid tumors.

A review on microsphere for novel drug delivery system

Microspheres are characteristically free flowing powders consisting of proteins or synthetic polymers which are biodegradable in nature and ideally having a particle size less than 200 µm. A well designed controlled drug delivery system can overcome some of the problems of conventional therapy and enhance the therapeutic efficacy of a given drug. There are various approaches in delivering a therapeutic substance to the target site in a sustained controlled release fashion. One such approach is using microspheres as carriers for drugs. It is the reliable means to deliver the drug to the target site with specificity, if modified, and to maintain the desired concentration at the site of interest without untoward effects. Microspheres received much attention not only for prolonged release, but also for targeting of anticancer drugs at tumor site. In future by combining various other strategies, microspheres will find the central place in novel drug delivery, particularly in diseased cell sorting, diagnostics, gene and genetic materials, safe, targeted and effective in vivo drug delivery and supplements as miniature versions of diseased organ and tissues in the body.

Novel Approaches For Colon Site-Specific Drug Delivery: An Overview Of Recent Advancements

Nowadays, various routes of administration have been explored for the effective delivery of the drug to the target site. The oral route is considered to be the most convenient for the administration of drugs to patients. But it has a serious drawback in conditions where localized delivery of the drug in the colon is required. The colon-targeted drug delivery system (CDDS) is a potential approach for systemic and topical drug delivery in treating inflammatory bowel diseases such as ulcerative colitis, Crohn’s disease, colon cancer, and amoebiasis. CDDS would provide direct treatment at the site of the disease, reduced dose, and reduced systemic adverse effects. CDDS should be able to release the drug into the colon, indicating that neither drug release nor absorption should take place in the stomach or small intestine, nor should the bioactive agent be degraded there. Instead, the drug should only be released and absorbed when it reaches the colon. The colon is a site for both local and systemic drug delivery. This review mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time-dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure-controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery systems. The review is also focused on the possible benefits and issues associated with the novel colon-targeted drug delivery system. Recent advancements in various approaches for designing colon-targeted drug delivery systems and their pharmaceutical applications are covered with a particular emphasis on formulation technologies.

Preparation and Characterization of Hydrogel Beads for Controlled Release of Amoxicillin

Amoxicillin trihydrate-loaded hydrogel beads were prepared and characterized as a controlled drug delivery system to improve patient compliance. An ionotropic gelation process was used to prepare the hydrogel beads using calcium chloride (CaCl2) as a crosslinking agent. The effects of CaCl2, sodium alginate, poloxamer 407 (PL) concentration, and preparation temperature were investigated. Spherical hydrogel beads were obtained with high encapsulation efficiency (85.74±1.09) %. FTIR analyses confirmed the compatibility of amoxicillin with the used excipients. In vitro swelling and cumulative drug release studies were performed over 24 hours in HCl medium, pH 1.2. Prepara-tion temperature was found to influence both the index of beads swelling (SI) and the cumulative release of amoxicil-lin. The study demonstrated the capability of PL to enhance the cumulative release of amoxicillin, correlating with swelling behavior. The proposed hydrogel beads have the potential as a promising drug delivery system for controlled release of amoxicillin, over 24 hours, and thus reduced dosing frequency.

Injectable Multifunctional Natural Polymer-Based Hydrogels for the Local Delivery of Therapeutic Agents

Mini Review Injectable Multifunctional Natural Polymer-Based Hydrogels for the Local Delivery of Therapeutic Agents Xue Bai 1，Annalisa Tirella1,2,* 1 Division of Pharmacy and Optometry, School of Health Science, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK. 2 BIOtech-Center for Biomedical Technologies, Department of Industrial Engineering, University of Trento, Via delle Regole 101, Trento 38123, Italy. * Correspondence: annalisa.tirella@unitn.it , annalisa.tirella@manchester.ac.uk (Annalisa Tirella). Received: 13 November 2022 Accepted: 15 November 2022 Published: 21 December 2022 Abstract: Hydrogels are water-based polymeric three-dimensional network with advantageous properties for the delivery of bioactive components, ranging from small therapeutic agents to therapeutic cells. Natural-based hydrogels have great potential as delivery vehicles for the local controlled release of therapeutic agents at the target site. Injectable hydrogels are designed to load therapeutic agents by simple mixing within the polymer solutions, as well as use nanoparticles able to respond to specific external conditions, such as temperature and pH. Herein, we present an overview of the properties of natural injectable hydrogels and recent developments for their use to control the local release of therapeutic agents; as well as strategies to crosslink in-situ multifunctional injectable hydrogels that act as therapeutical depot system. The mini review focuses on alginate-based injectable hydrogels as controlled drug delivery systems, presenting advantages and challenges of their application in cancer therapy