Drug Release Mechanism Research Articles

Composite Mineralized Collagen/Polycaprolactone Scaffold-Loaded Microsphere System with Dual Osteogenesis and Antibacterial Functions.

Biomaterials play an important role in treating bone defects. The functional characteristics of scaffolds, such as their structure, mechanical strength, and antibacterial and osteogenesis activities, effectively promote bone regeneration. In this study, mineralized collagen and polycaprolactone were used to prepare loaded porous scaffolds with bilayer-structured microspheres with dual antibacterial and osteogenesis functions. The different drug release mechanisms of PLGA and chitosan in PLGA/CS microspheres caused differences in the drug release models in terms of the duration and rate of Pac-525 and BMP-2 release. The prepared PLGA(BMP-2)/CS(Pac-525)@MC/PCL scaffolds were analyzed in terms of physical characteristics, bioactivity, and antibacterial properties. The scaffolds with a dimensional porous structure showed similar porosity and pore diameter to cancellous bone. The release curve of the microspheres and scaffolds with high encapsulation rates displayed the two-stage release of Pac-525 and BMP-2 over 30 days. It was found that the scaffolds could inhibit S. aureus and E. coli and then promote ALP activity. The PLGA(BMP-2)/CS(Pac-525)@MC/PCL scaffold could be used as a dual delivery system to promote bone regeneration.

Synthesis and characterization of Gellan gum-based hydrogels for the delivery of anticancer drug etoposide

Present research work reports the synthesis of Gellan gum (Gg) and methacrylic acid (MA) based grafted hydrogels (Gg-cl-poly(MA)) crosslinked using N, N′– methylene-bis-acrylamide (MBA) and the evaluation of their efficiency to be used as a sustained drug delivery carrier for anticancer drug i.e., etoposide. Various characterization techniques like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed the grafting of Gg with MA and the formation of crosslinked Gg-cl-poly(MA) hydrogel polymer. The synthesized hydrogel showed pH-dependent swelling properties and exhibited a maximum swelling capacity of 867 % under optimized environmental conditions. The Gg-cl-poly(MA) was biocompatible and non-cytotoxic, which was confirmed by the hemolytic and cytotoxic tests. The release dynamics of etoposide from the Gg-cl-poly(MA) polymer matrix was checked under specific physiological conditions. Drug release was found to be significantly higher in the acidic medium, followed by the neutral and alkaline medium. This clearly indicated that etoposide drug release through synthesized hydrogel was stomach-specific and it is effective for the treatment of stomach cancer. The release mechanism of the etoposide drug was a Fickian-type diffusion mechanism in the acidic medium and a non-Fickian-type diffusion mechanism in the neutral and alkaline medium. The release profile of the etoposide was best fitted to the first-order rate model. The results showed that the synthesized hydrogel (i.e., Gg-cl-poly(MA)) was biocompatible, non-toxic, and could be used for the treatment of stomach cancer.

In vitro drug release profiling of Sirolimus polymeric microparticles coated long-acting stents

In the realm of arterial disease interventions, drug-eluting stents (DES) have become a vital therapeutic choice in preventing atherosclerotic plaque formation and restenosis and facilitating vessel healing. Sirolimus-encapsulated poly Lactic-co-Glycolic acid (PLGA) Microparticles (MPs) were developed using solvent evaporation. MPs were freeze-dried with a cryoprotectant and coated on the stent surface using an efficient and reproducible nitrogen-assisted spray coating technique. The MPs displayed a uniform distribution particle size of 4.38 ± 1.1 μm, span value of 0.88 ± 0.02, coating mass transfer efficiency of 13.45 ± 1.1 % on the stent, and a coating time of ≤ 2 min per stent. Post sterilization, the particle size and morphology of the coated stents remained unchanged. Accelerated in vitro drug release profiles were evaluated under different conditions, indicating significant influences based on dissolution methods ranging from 28.2 %±4.3 %, 42.5 %±5.3 %, 76.6 %±4.7 %, and 84.25 %±3.1 % for dialysis bag (DB), vessel simulating flow-through cell (vFTC), flow-through cell (FTC), and sample and separate (SS) technique respectively for 48 h. The drug release mechanism from the coated stents is governed by the combination of the Korsmeyer Peppas and Higuchi models. The developed dissolution method exhibited discriminative effectiveness when evaluated with critical formulation attributes and process parameter variations. The 48 h accelerated drug release studies correlated well with the 6-month real-time release rate with an R2 value of 0.9142 and Pearson’s R2 of 0.9561. Ex-vivo studies demonstrated the permeation of MPs into artery tissues. Stability studies confirmed that MPs coated stents maintained desired properties at 4 °C and 30 °C/65 % RH for 6 months. Overall, these findings contribute to advancing stent technology, suggesting the potential for improvement of arterial interventions and enhanced patient outcomes.

Review on Nanogel as a Novel Platform for Smart Drug Delivery System

One of the most popular applications of nanotechnology in both topical and internal medicine administration to the body is nanogel technology. The materials comprising the nanoparticulate frameworks are less than 100 nm in a single measurement. The goal of this review paper is to provide a concise overview of the most recent developments in the nanogel medicine delivery framework with regard to drug loading and swelling. It categorises according to links (chemical and physical) and responding behaviour. This article is to give a broad overview of nanogels, their innovative use in many contexts, and current synthesis techniques. NGs use drugs for a variety of reasons, including diagnostics, gene targeting, organ targeting, and many more. Different pulmonary, nasal, transdermal, intra-ocular, oral, and parenteral routes can be used to give NGs. The primary goals of this review are to present broad details on NGs, their characteristics, multiple categories, medication targeting strategies, kinds of drug delivery systems, assessment techniques, and cutting-edge uses for NGs in depth. Keywords: Nanogel, DLS, CD, mechanism of drug release, classification, application

Carrier-free nano-prodrugs for minimally invasive cancer therapy.

An anticancer nanodrug with few side effects that does not require the use of a nanocarrier, polyethylene glycol, or other additives has been developed. We have fabricated nano-prodrugs (NPDs) composed only of homodimeric prodrugs of the anticancer agent SN-38, which contains a disulfide bond. The prodrugs are stable against hydrolysis but selectively release SN-38 when the disulfide bond is cleaved by glutathione, which is present in high concentrations in cancer cells. The best-performing NPDs showed good dispersion stability in nanoparticle form, and animal experiments revealed that they possess much higher antitumor activity than irinotecan, a clinically applied prodrug of SN-38. This performance was achieved by improving tumor accumulation due to the size effect and targeted drug release mechanism. The present study provides an insight into the development of non-invasive NPDs with high pharmacological activity, and also offers new possibilities for designing prodrug molecules that can release drugs in response to various kinds of triggers.

Slowing Down the "Magic Bullet": Encapsulation of Imatinib in Fe-MOF for Cardiotoxicity Reduction and Improvement in Anticancer Activity.

Imatinib, a small molecule kinase inhibitor, is used as a cancer growth blocker. However, one of its most serious side effects is congestive cardiac failure. Reducing drug toxicity may be achieved through the use of drug delivery systems. Biocompatible metal-organic framework (MOF) materials, namely FeMIL-100 and FeMIL-101-NH2, were employed as potential imatinib carriers. They efficiently delivered the drug as an anticancer agent while minimizing cardiotoxicity. Notably, the release of imatinib from FeMIL-100 was rapid in acidic conditions and slower in pH-neutral environments, allowing targeted delivery to cancer cells. The carrier's pH-dependent stability governed the drug release mechanism. Two release models-Korsmeyer-Peppas and Weibull-were fitted to the experimental data and discussed in terms of drug release from a rigid microporous matrix. Cytotoxicity tests were conducted on two cell lines: HL60 (a model cell line for acute myeloid leukemia) and H9c2 (a cell line for cardiomyocytes). Overall, the metal-organic framework (MOF) carriers mitigated imatinib's adverse effects without compromising its effectiveness.

Applications of Tissue Engineering

This article is written from a beginner's perspective to elucidate the concept of tissue engineering through its applications. It elaborates on the role of tissue engineering in burn skin treatment and drug delivery systems for cancer therapy. The first part of this article discusses the challenges and current issues related to burn injuries and the engineered techniques for their treatment. It highlights the need for scaffolds in skin tissue regeneration, along with the materials and methods used for treatment. The second part focuses on drug delivery mechanisms in tissue engineering, specifically in cancer treatments, explaining the carrier and release mechanisms of drugs targeting cancer cells. Most information was gathered from scientific articles, following the selection of focused applications. The basics of these applications were studied and explained in layman's terms, forming the foundation for an application-based learning experience. Personal reflections and comments are synthesized in the conclusion, making it accessible for those who want to learn about tissue engineering at a glance.

A new intracellularly regulated release pattern controlled by coordinated carrier cracking and drug release

To further develop intracellular delivery systems of macromolecular drugs, understanding the cracking mechanisms and drug release behaviors of environment-responsive carriers, as well as their intrinsic linkages, is essential for achieving personalized or diversified delivery of macromolecular drugs. Herein, we designed a class of degradable dendritic mesoporous nanoparticles (DDMSNs), utilizing very large cavities and tetrasulfide bonds in the skeleton to achieve high drug loading and release within tumor cells. To comprehensively understand and develop intracellular drug delivery systems, this study delved deeper into the delivery of tetrasulfide-bonded DDMSNs, including chemical reactions, cracking kinetics, and release kinetics. First, the drug release of the DDMSNs within the cytoplasm was closely related to the chemical reaction of tetrasulfide bonds. Thus, based on experiments, the oxidation–reduction mechanism of tetrasulfide-bonded DDMSNs was explained, and the relationship was elaborated between cracking and drug release of the DDMSNs with different sulfur contents. To further explore this relationship, the cracking behavior, drug-loading capacity and release capacity of the DDMSNs was investigated with the different sulfur contents in different simulated environments, and in MDA-MB-231 cancer cells. Inspired by the reaction kinetic calculations, we analyzed the cracking and drug release behavior of the DDMSNs, and ultimately achieved dual cracking secondary drug release of the carriers by controlling the content of sulfur elements. Here, we report improved biomedical materials for advanced, customized, and intentional intracellular delivery of therapeutic macromolecules, in which theoretical calculations and experimental components were combined to study the mechanism of drug release influenced by carrier cracking, providing essential guidance for designing advanced drug delivery systems through a chemical engineering method.

Preparation and Characterization of Sodium Alginate‐Based Hydrogel for Delivery of Hydrophilic Drug Metformin Hydrochloride

AbstractThis research delves into the development of a hydrogel based on sodium alginate (Na‐Alg), CMTKG and PSA for the controlled release of Metformin Hydrochloride (Metformin HCl), a commonly used drug for the treatment of type 2 diabetes. The hydrogel was synthesized via a free radical mechanism using N, N′‐methylene‐bis(acrylamide) (MBA) as a crosslinker and potassium persulphate (KPS) as an initiator. The hydrogels were analyzed using techniques such as ATR‐FTIR, and SEM. The research also investigated swelling behaviour, drug loading, drug encapsulation efficiency, and release kinetics of Metformin HCl. The finding revealed that the hydrogel exhibited pH‐responsive metformin HCl release, with higher drug release perceived at pH 7.4 compared to pH 1.2. Mathematical models were employed to study the drug release mechanism, indicating diffusion as a mechanism liable for the drug release from the hydrogel. Moreover, the synthesized metformin HCl‐loaded Na‐Alg/PSA/CMTKG hydrogel shows excellent anti‐diabetic activity on α‐amylase and α‐glucosidase enzyme. Henceforth, the formulated hydrogel reveals potential for facilitating the targeted release of Metformin HCl, offering opportunities for improving patient amenability and lessening side effects related to frequent dosing.

A pH and near-infrared light dual-responsive drug delivery system based on TiO2 nanotube arrays modified with polydopamine and Fe3+

This paper reports a novel drug delivery system based on TiO2 nanotube arrays (TNTs) modified with polydopamine (PDA) and Fe3+, which can load and release alendronate (NaAL), a drug for osteoporosis treatment, in a pH-responsive and near-infrared light-triggered manner. The samples were characterized by electron scanning microscopy(SEM/EDS), Fourier Transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), X-ray Photoelectron Spectroscopy(XPS) and Thermogravimetry(TG). The drug release behavior of the samples was investigated under different pH and light conditions. The results showed that the TNTs-PDA-Fe3+ had improved drug loading capacity compared with the TNTs and TNTs-PDA. The drug release was pH-responsive and near-infrared light-triggered, the drug release from the sample with a pH of 4.6 was much greater than the pH of 11 and 7.4, and the photothermal conversion effificiency of TNTs-PDA-Fe3+-NaAL was 32.9 %. The drug release mechanism was attributed to the coordination bond between Fe3+ and NaAL, and the photothermal effect of the PDA. The cytotoxicity and biocompatibility of the samples were evaluated by MTT assay using mouse embryonic osteoblasts cells. The results indicated that the samples had no obvious cytotoxicity and could promote the cell proliferation and differentiation. The paper concludes that the TNTs-PDA-Fe3+-NaAL system is a potential implantable drug delivery platform for bone-related diseases.

3D Printed Drug Delivery Systems in Action-Magnetic Resonance Imaging and Relaxometry for Monitoring Mass Transport Phenomena.

The hypothesis of the study was that (1) 3D printed drug delivery systems (DDS) could be characterized in situ during drug release using NMR/MRI techniques in terms of mass transport phenomena description (interfacial phenomena), particularly for systems dealing with two mobile phases (e.g., water and low molecular weight liquid polymer); (2) consequently, it could be possible to deduce how these interfacial mass transport phenomena influence functional properties of 3D printed DDS. Matrix drug delivery systems, prepared using masked stereolithography (MSLA), containing poly(ethylene glycol) diacrylate (PEGDA) and low molecular weight polyethylene glycol (PEG) with ropinirole hydrochloride (RH) were studied as example formulations. The PEGDA to PEG (mobile phase) concentration ratio influenced drug release. It was reflected in spatiotemporal changes in parametric T2 relaxation time (T2) and amplitude (A) images obtained using magnetic resonance imaging (MRI) and T1-T2 relaxation time correlations obtained using low-field time-domain nuclear magnetic resonance (LF TD NMR) relaxometry during incubation in water. For most of the tested formulations, two signal components related to PEG and water were assessed in the hydrated matrices by MRI relaxometry (parametric T2/A images). The PEG component faded out due to outward PEG diffusion and was gradually replaced by the water component. Both components spatially and temporally changed their parameters, reflecting evolving water-polymer interactions. The study shows that dynamic phenomena related to bidirectional mass transport can be quantified in situ using NMR and MRI techniques to gain insight into drug release mechanisms from 3D printed DDS systems.

Polyurea-urethane Temperature-responsive Hydrogels for Sustained Delivery of Anti-VEGF Therapeutics.

Temperature-responsive hydrogels, or thermogels, have emerged as a leading platform for sustained delivery of both small molecule drugs and macromolecular biologic therapeutics. Although thermogel properties can be modulated by varying the polymer's hydrophilic-hydrophobic balance, molecular weight and degree of branching, varying the supramolecular donor-acceptor interactions on the polymer remains surprisingly overlooked. Herein, to study the influence of enhanced hydrogen bonding on thermogelation, we synthesized a family of amphiphilic polymers containing urea and urethane linkages using quinuclidine as an organocatalyst. Our findings showed that the presence of strongly hydrogen bonding urea linkages significantly enhanced polymer hydration in water, in turn affecting hierarchical polymer self-assembly and macroscopic gel properties such as sol-gel phase transition temperature and gel stiffness. Additionally, analysis of the sustained release profiles of Aflibercept, an FDA-approved protein biologic for anti-angiogenic treatment, showed that urea bonds on the thermogel were able to significantly alter the drug release mechanism and kinetics compared to usage of polyurethane gels of similar composition and molecular weight. Our findings demonstrate the unrealized possibility of modulating gel properties and outcomes of sustained drug delivery through judicious variation of hydrogen bonding motifs on the polymer structure.

Microfluidic aerosol-assisted synthesis of gefitinib anticancer drug nanocarrier based on chitosan natural polymer

An aerosol-assisted approach was devised to synthesize gefitinib anticancer drug-loaded chitosan nanocarriers (GefNCs). The nanocarrier synthesis involves mixing and interacting gefitinib molecules with chitosan natural polymer within a microfluidic chip. The combination was nebulized with an on-chip integrated micropneumatic nebulizer with N2 as the nebulizer gas. The aerosol was collected in a beaker containing a glutaraldehyde cross-linking agent while magnetically stirring. The chip was created by CO2 laser engraving on polymethyl methacrylate sheets. The synthesized GefNCs were characterized using FTIR, DLS, FESEM, and TEM. The FESEM images revealed a nanoparticle size distribution of 18.5 ± 4.6 nm. After adjusting numerous experimental parameters such as chip design, polymer concentration, solution flow rate, and nebulizer gas flow rate, the synthesized nanocarrier's release mechanism was investigated using various kinetic models. The results demonstrated that the release behavior of GefNCs is pH-sensitive and greater at acidic pH values than physiological pH, making the synthesized nanocarrier a potential for targeted gefitinib delivery to cancer cells. Furthermore, the kinetic studies revealed that the drug's release mechanism best matches Fick's diffusion rule. Under optimal conditions, the encapsulation efficiency was 77.8 %. The cytotoxicity of the produced nanocarrier was investigated on the A549 non-small cell lung carcinoma. The MTT test revealed that the produced nanocarrier had a lower IC50 than the free medication. Furthermore, cytotoxicity experiments on empty nanocarriers revealed that the materials utilized to synthesize nanocarriers have no appreciable cytotoxicity. The developed microfluidic-assisted approach provides a quicker synthesis procedure with a high encapsulation efficiency.

Nanosponges-Road Less Explored Changing Drug Delivery Approach: An Explicative Review.

Nanotechnology exhibits a wide range of applications in the domain of disease therapy, diagnosis, biological detection, and environmental safeguards. The cross-linked polymeric nanosponges (NSs) are a nanoscale drug carrier system with a 3D porous structure and high entrapment efficacy. NSs up to the fourth generation are currently accessible and can serve as a delivery system for both hydrophilic and hydrophobic drugs. The delivery system exhibits superiority over alternative methods due to its ability to achieve controlled and targeted drug delivery. The colloidal structure of NSs facilitates the encapsulation of a wide range of agents such as proteins and peptides, enzymes, antineoplastic drugs, volatile oil, vaccines, DNA, etc. NSs efficiently overcome the challenges associated with drug toxicity and poor aqueous solubility. NS formulations have been explored for various applications like gaseous encapsulation, enzyme immobilization, antifungal therapy, poison absorbent, water purification, etc. This review provides a comprehensive analysis regarding methods of synthesis, distinct polymeric NSs, mechanism of drug release, factors affecting NS development, applications, and patents filed in the field of NSs. Herein, the recently developed NS formulations, their potential in cancer therapy, and current progressions of NS for SARS-CoV-2 management are also deliberated with special attention, focusing on the significant challenges and future directions.

Kinetic study of in vitro release of curcumin from chitosan biopolymer and the evaluation of biological efficacy

Sustained release of curcumin from the polymeric carrier system chitosan, a natural biopolymer material derived from chitin originated from natural shrimp shell waste, was studied. Six kinetic models, zero order, first order, Korsmeyer–Peppas (KP), Peppas – Sahlin (PS), Higuchi, and Hixson–Crowell, were applied to study the drug release kinetics. The release mechanism of the drug from the curcumin-chitosan composite was evaluated by changing the pH, ionic strength of the release media, and drug concentration. KP and PS models were selected among the studied models to investigate the drug release mechanism from the chitosan biopolymer based on the R2 values (R2 > 0.99). The model constants m in the PS model and n in the KP model stand for the case II relaxation and Fickian diffusion contribution, respectively. The n being < 0.43 in the KP model suggests that the Fickian diffusion governs the drug release. Furthermore, there is a noticeable difference between the values obtained for model parameters m and n in the PS and KP models, indicating that Case II relaxation and Fickian diffusion play crucial roles in the curcumin release mechanism from chitosan. Polymer relaxation has been proven to play a predominant role in releasing curcumin from the composite at lower ionic strengths and higher pH values. Anti-inflammatory activity was tested using the egg-albumin denaturation assay, and the diphenyl-2-picrylhydrazyl assay was carried out to determine the antioxidant activity of the composite. The composite material showed IC50 values of 0.29 mg/ mL and 1.08 mg/ mL for anti-inflammatory and anti-oxidant activities, respectively. The drug composite has shown antibacterial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, which are highly effective against S.aureus. The resulting inhibition zones for S.aureus were 13.34 ± 0.34 mm, 16.34 ± 0.60 mm, and 13.34 ± 0.73 mm for 5, 10, and 20 mg/ml concentrations, respectively. The drug composite’s minimum inhibitory concentration/ minimum bactericidal concentration ratio for S.aureus, K. pneumoniae, and P.aeruginosa was greater than 4, suggesting that they cause bacteriostatic effects.

Drug Release Study of Polyvinyl Alcohol-Gelatin-Montmorillonite Bionanocomposite Hydrogel Drug Delivery Systems Loaded with Clindamycin

One of the challenges facing medical science is the proper formulation of drug delivery systems for the correct transfer of active pharmaceutical ingredients to the body. Polymer and nanocomposite hydrogels have been considered ideal options in the preparation of drug delivery systems due to their proper properties, such as hydrophilicity and biocompatibility. In this, our research, described in this manuscript, the drug release from polyvinyl alcohol (PVA)-gelatin-montmorillonite (MMT) bionanocomposite hydrogel drug delivery systems loaded with clindamycin was studied. The structural and physical properties of prepared nanocomposite hydrogels were investigated using X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmette-Teller (BET) analysis, gel fraction and swelling tests. The results showed that by adding MMT clay to PVA-gelatin hydrogels, the amount of gel fraction increased, and due to the decrease in the size of the pores, the amount of swelling decreased. The results of the drug release tests showed that the release rate of clindamycin was inversely related to the percentage of MMT added to the nanocomposite hydrogel. The results also showed that the shape of the drug delivery system and its dimensions affected the release rate of clindamycin. The dominant mechanism of drug release in all samples was found to be Fickian transport. Considering the favorable in-vitro drug release performance of our PVA-gelatin-MMT nanocomposite hydrogels in the release of clindamycin, it was concluded that they are suitable options for preparing practical drug delivery systems with controlled drug release ability.

Drug-eluting contact lenses: Progress, challenges, and prospects.

Topical ophthalmic solutions (eye drops) are becoming increasingly popular in treating and preventing ocular diseases for their safety, noninvasiveness, and ease of handling. However, the static and dynamic barriers of eyes cause the extremely low bioavailability (<5%) of eye drops, making ocular therapy challenging. Thus, drug-eluting corneal contact lenses (DECLs) have been intensively investigated as a drug delivery device for their attractive properties, such as sustained drug release and improved bioavailability. In order to promote the clinical application of DECLs, multiple aspects, i.e., drug release and penetration, safety, and biocompatibility, of these drug delivery systems were thoroughly examined. In this review, we systematically discussed advances in DECLs, including types of preparation materials, drug-loading strategies, drug release mechanisms, strategies for penetrating ocular barriers, in vitro and in vivo drug delivery and penetration detection, safety, and biocompatibility validation methods, as well as challenges and future perspectives.

Alginate/hyaluronic acid/gelatin ternary blended films as pH-sensitive drug carriers: In vitro ampicillin release and kinetic studies

Researchers continuously focused on the fabrication of innovative drug delivery systems to prevent microbial infections while minimizing systemic side effects. Among these, pH-sensitive antibiotic release systems based on bio-based materials have gained great attention due to their ability to precisely modulate drug kinetics and enhance therapeutic efficacy. Herein, pH-sensitive alginate/hyaluronic acid/gelatin ternary blended films were fabricated for the controlled release of ampicillin. Swelling capacity, hydrolytic degradation profile, pH reversibility and in vitro ampicillin release behavior of produced films were investigated in both simulated gastric (pH 1.2) and intestinal (pH 7.4) environments. The cumulative release amount of ampicillin at pH 1.2 (61.0 ± 1.07 mg drug/g polymer) was greater than that of at pH 7.4 (43.0 ± 1.05 mg drug/g polymer) proved that release behavior of ampicillin for produced films is pH-dependent. Based on the fitted release data, best fit was found as the first-order kinetic model with the highest R2 values of 0.966 and 0.962 for both pH conditions. According to Korsmeyer-Peppas model, drug release mechanism is also controlled by case II-transport. Furthermore, produced films demonstrated excellent cytocompatibility. All results revealed that obtained films could be a promising drug carrier to traditional targeting systems for site-specific, pH-sensitive ampicillin delivery in both gastric and intestine.

Modulation of mechanical properties of low molecular weight supramolecular hydrogels of calcium cholate by drugs of varying hydrophobicity: Effect on drug release, antioxidant, and antibacterial properties

Bile salt based low-molecular-weight supramolecular hydrogels (LMWSH) serve as an appealing framework for drug delivery applications, owing to their natural origin, biocompatibility, and the peculiar distribution of hydrophobic and hydrophilic domains. In this work, LMWSH based on an ionotropic gel of sodium cholate assisted by Ca2+ ions (CaC) was developed as a drug delivery system for both hydrophilic and hydrophobic drugs. Diosgenin, Quercetin, Rutin, and Amygdalin were chosen as model drugs, having varying hydrophobicity. The mechanical strength of the CaC hydrogel is enhanced by increasing the hydrophobicity of the loaded drug. The close-knit mesh design of CaC hydrogels loaded with hydrophobic drugs resulted in controlled drug release compared to the hydrophilic drugs. Drug-loaded CaC hydrogels exhibited good swelling and thixotropy, making them suitable for injectable formulations. In kinetic drug release, both relaxation and diffusion mechanisms play a pivotal role. The antioxidant and antibacterial activity of the loaded drugs increased synergistically in the hydrogels. Thus, due to these properties, the hydrogels can be safely used as topical gels against wound healing. This study shows that bile salts exhibit potential to enhance the delivery of both hydrophobic and hydrophilic drugs, making them promising candidates for biomedical applications.

To Formulate and Evaluate the Metformin Hydrochloride Floating Tablet

The aim of the research was to create a gastro retentive system for prolonged release of metformin HCl in the proximal part of the gastrointestinal tract (GIT) in the form of an oral floating tablet. Metformin HCl is an antidiabetic biguanide with poor bioavailability and an absorption window in the upper GIT. Floating tablets were prepared using a wet granulation method containing the natural polymers guar gum and kcarrageenan and the synthetic polymer HPMC K100 (HPMC) either alone or in combination. Sodium bicarbonate and citric acid were used as gas generators. Floating tablets were evaluated for weight variation, hardness and friability, drug content, swelling index, in vitro buoyancy and in vitro drug release. The formulation is optimized based on buoyancy, matrix integrity and in vitro drug release in simulated gastric fluid at pH 1.2. A formulation formulated with a combination of 6 wt. % k-carrageenan and 11 wt. % guar gum showed good gel strength, stable and continuous buoyancy for 12 hours, minimal buoyancy delay of 58 seconds, and good matrix integrity during dissolution period. The drug release of the optimized formulation followed the Korsmeyer- Peppas model and the mechanism was non-Fickian/divergent. PXRD and DSC studies showed partial amorphization of the drug. The mechanism of drug release appeared to be a diffusion mechanism. Stability studies have shown that the drug does not degrade when stored for 3 months at 40˚C.