Zero-order release from biphasic polymer hydrogels

Intestinal-specific oral delivery of lactoferrin with alginate-based composite and hybrid CaCO3-hydrogel beads

Sodium alginate hydrogel beads and sodium alginate/gellan gum composite hydrogel beads crosslinked by calcium chloride were prepared with different alginate concentrations (3-20 mg·mL-1). Additionally, a simple method for growing CaCO3in situ on the hydrogel to create novel inorganic-organic hybrid hydrogel beads was presented. FT-IR analysis revealed the involvement of hydrogen bonding and electrostatic interactions in bead formation. Swelling behavior in acidic conditions showed a maximum of 13 g/g for composite hydrogels and CaCO3-incorporated hybrid hydrogels. Lactoferrin encapsulation efficiency within these hydrogels ranged from 44.9 to 56.6%. In vitro release experiments demonstrated that these hydrogel beads withstand harsh gastric environments with <16% cumulative release of lactoferrin, achieving controlled release in intestinal surroundings. While composite sodium alginate/gellan gum beads exhibited slower gastrointestinal lactoferrin digestion, facile synthesis and pH responsiveness of CaCO3-incorporated hybrid hydrogel also provide new possibilities for future studies to construct a novel inorganic-organic synergetic system for intestinal-specific oral delivery.

Madhuca indica oil-entrapped buoyant galactomannan hydrogel microspheres for controlling epileptic seizures

A stable Madhuca indica oil-in-water nanoemulsion (99-210 nm, zeta potential: > - 30 mV) was produced employing Tween 20 (surfactant) and Transcutol P (co-surfactant) (3:1). The nanoemulsion (oil: Smix = 3:7, 5:5, and 7:3) were subsequently incorporated into oxcarbazepine-loaded carboxymethylxanthan gum (DS = 1.23) dispersion. The hydrogel microspheres were formed using the ionic gelation process. Higher oil concentration had a considerable impact on particle size, drug entrapment efficiency, and buoyancy. The maximum 92 % drug entrapment efficiency was achieved with the microspheres having oil: Smix ratio 5:5. FESEM study revealed that the microspheres were spherical in shape and had an orange peel-like surface roughness. FTIR analysis revealed a hydrogen bonding interaction between drug and polymer. Thermal and x-ray examinations revealed the transformation of crystalline oxcarbazepine into an amorphous form. The microspheres had a buoyancy period of 7.5 h with corresponding release of around 83 % drug in 8 h in simulated stomach fluid, governed by supercase-II transport mechanism. In vivo neurobehavioral studies on PTZ-induced rats demonstrated that the microspheres outperformed drug suspension in terms of rotarod retention, number of crossings, and rearing activity in open field. Thus, Madhuca indica oil-in-water nanoemulsion-entrapped carboxymethyl xanthan gum microspheres appeared to be useful for monitoring oxcarbazepine release and managing epileptic seizures.

Computational quality-by-design strategy to validate high-performance liquid chromatography method for the estimation of meloxicam in bulk dosage forms and milk samples

Bovine clinical mastitis has significant repercussions for farmers across the globe. Meloxicam, a COX-2 inhibitor, attenuates mastitis symptoms and is also approved for veterinary use. An RP-HPLC (Reverse Phase-High Performance Liquid Chromatography) method development and validation is essential in the pharmaceutical industry to assess API (Active Pharmaceutical Ingredient) quantity present in the pharmaceutical dosage forms. RP-HPLC method of meloxicam was developed and optimized with the aid of QbD (Quality by Design) using Box-Behnken design (BBD). The pH of the aqueous mobile phase, acetonitrile (ACN) percentage, and column temperature were chosen as influence variables, and retention time (RT) and tailing factor (Tf) were selected as response variables. The optimum experimental conditions were selected as pH ~ 3 of the aqueous mobile phase, 65% v/v ACN, and 30˚C as column temperature. The drug was eluted at 6.02 min RT with 1.18 as Tf. The method was subjected to validation for accuracy, linearity, precision, range, sensitivity, and robustness and was found to comply with ICH Q2 (R1) guidelines. The in vitro bioequivalent studies were performed in hydrochloric acid, pH ~ 1.2; acetate buffer, pH ~ 4.5; and phosphate buffer, pH ~ 6.8 for two veterinary brands of meloxicam tablets, and their release profiles were compared by mathematical models. Both the brands, brand 1 and 2 exhibited significant (Unpaired t-test, P < 0.05) differences in dissolution efficiency (DE) and mean dissolution time (MDT) except DE at pH 1.2. However, brands 1 and 2 showed similarity (f2 > 50) in terms of release of meloxicam except at pH 6.8 (f2 = 47.01). The in vitro release of meloxicam followed Peppas kinetics except for brand 2 at pH 6.8, where it followed the Higuchi model. Moreover, the recovery of meloxicam extracted with ACN in the milk sample was estimated to be 99.67 ± 0.58% significantly (Unpaired t-test, P < 0.05) higher than 90.34 ± 6.77% extracted with methanol. In conclusion, the optimized and validated RP-HPLC method of meloxicam may further be used for the analysis of drug content in pharmaceutical dosage forms in addition to biological fluids.

Formulation optimization and evaluation of oromucosal in situ gel loaded with silver nanoparticles prepared by green biosynthesis

Treating oral diseases remains challenging as API is quickly washed out of the application site by saliva turnover and mouth movements. In situ gels are a class of application forms that present sol-gel transition's ability as a response to stimuli. Their tunable properties are provided using smart polymers responsible for stimuli sensitivity, often providing mucoadhesivity. In this study, antimicrobial in situ gels of thermosensitive and pH-sensitive polymers loaded with silver nanoparticles were prepared and evaluated. The nanoparticles were prepared by green synthesis using Agrimonia eupatoria L. extract. According to the data analysis, the in situ gel with the most promising profile contained 15 % of Pluronic® F-127, 0.25 % of methylcellulose, and 0.1 % of Noveon® AA-1. Pluronic® F-127 and methylcellulose significantly increased the viscosity of in situ gels at 37 °C and shear rates similar to speaking and swallowing. At 20 °C, a behavior close to a Newtonian fluid was observed while being easily injectable (injection force 13.455 ± 1.973 N). The viscosity of the formulation increased with temperature and reached 2962.77 ± 63.37 mPa·s (37 °C). A temperature increase led to increased adhesiveness and rigidity of the formulation. The critical sol-gel transition temperature at physiological pH was 32.65 ± 0.35 °C. 96.77 ± 3.26 % of Ag NPs were released by erosion and dissolution of the gel after 40 min. The determination of MIC showed effect against E. coli and S. aureus (0.0625 mM and 0.5000 mM, respectively). The relative inhibition zone diameter of the in situ gel was 73.32 ± 11.06 % compared to gentamicin sulfate. This work discusses the optimization of the formulation of novel antibacterial in situ gel for oromucosal delivery, analyses the impact of the concentration of excipients on the dependent variables, and suggests appropriate evaluation of the formulation in terms of its indication. This study offers a promising dosage form for local treatment of oral diseases.

Self-assembling Organogels Loaded with Tenoxicam for Local Intensive Pain and Inflammation Cure: In Vitro and In Vivo Correlation

Due to tenoxicam (TX)'s poor aqueous solubility (0.072 mg/ml), it is poorly absorbable in the GIT, and the long-term oral administration of TX may cause severe GIT disturbances. Topical administration of TX can help in bypassing the GIT adverse effects. Therefore, in the present work, we constructed different pluronic/lecithin organogels (PLOs) for topical delivery of TX. PLO was constructed simply via direct mixing of an aqueous pluronic solution with lecithin solution. The prepared PLO formulations were characterized for their physicochemical properties including pH, drug content, visual inspection, viscosity, and spreadability. Also, the in vitro release and kinetic studies were carried out to investigate the mechanism of drug release. Moreover, the in vivo studies were carried out by investigating the anti-inflammatory and analgesic activities using albino male rats. The results showed that the modified PLOs have good physicochemical properties. The viscosity of the modified gels is a direct proportionality with both lecithin and pluronic concentrations. Also, subsequently, the drug release rate is directly proportional to gel viscosity. Moreover, the in vivo studies showed that the modified PLOs (F19) showed a significant ( < 0.05%) paw edema inhibition and pain analgesia compared with other investigated groups. Also, the results indicated that the increase in dose is accompanied by higher activity and a longer duration of action which extended to 12 h. Hence, the modified PLOs are promising safe candidates or vehicles for effective TX loading with sustained delivery behavior.

Development of Sustained Release System Based on High Water-Absorbable Gel Formation Using Croscarmellose Sodium, Alkaline Excipients and HPMC (ACSH SR System); Novel Application of Croscarmellose Sodium as a Gel Former

PURPOSE

Croscarmellose sodium, generally used as a superdisintegrant in pharmaceutical formulations, is hydrolyzed to form the gel structure under basic pH conditions. Utilizing this property of croscarmellose sodium, we developed a novel sustained release (SR) system.

METHODS

Immediate release (IR) and SR tablets containing croscarmellose sodium, alkaline excipients and/or hydroxypropyl methylcellulose (HPMC) were prepared and examined for wet strength and in vitro drug release behavior. In vivo oral drug absorption was evaluated for IR tablets, HPMC tablets and our novel SR tablets in fasted Beagle dogs.

RESULTS

To form the gel structure even under the physiological condition, alkaline excipients were added into the formulation containing croscarmellose sodium. Furthermore, HPMC was used to make the gel structure strong enough against mechanical destructive forces. The novel alkalized croscarmellose sodium-HPMC (ACSH) SR tablet, consisting of croscarmellose sodium, alkaline excipients, and HPMC, successfully sustained the release of acetaminophen, ibuprofen, or nicardipine hydrochloride, compared with the IR tablets. The ACSH SR system provided a better release of acetaminophen than the HPMC tablet without croscarmellose sodium in the release study using a small volume of liquid, suggesting that substantial release and subsequent absorption would be expected in the distal intestinal segments after oral dosing. The in vivo oral absorption study revealed that the ACSH SR system successfully suppressed and prolonged the plasma concentrations of acetaminophen.

CONCLUSION

This novel ACSH SR system prepared with croscarmellose sodium, alkaline excipients, and HPMC, would be a promising SR formulation for enabling substantial drug absorption in the distal intestinal segments.

Development of Diclofenac Sodium 3D Printed Cylindrical and Tubular-Shaped Tablets through Hot Melt Extrusion and Fused Deposition Modelling Techniques

The present study aimed to develop 3D printed dosage forms, using custom-made filaments loaded with diclofenac sodium (DS). The printed tablets were developed by implementing a quality by design (QbD) approach. Filaments with adequate FDM 3D printing characteristics were produced via hot melt extrusion (HME). Their formulation included DS as active substance, polyvinyl alcohol (PVA) as a polymer, different types of plasticisers (mannitol, erythritol, isomalt, maltodextrin and PEG) and superdisintegrants (crospovidone and croscarmellose sodium). The physicochemical and mechanical properties of the extruded filaments were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD) and tensile measurements. In addition, cylindrical-shaped and tubular-shaped 3D dosage forms were printed, and their dissolution behaviour was assessed via various drug release kinetic models. DSC and XRD results demonstrated the amorphous dispersion of DS into the polymeric filaments. Moreover, the 3D printed tablets, regardless of their composition, exhibited a DS release of nearly 90% after 45 min at pH 6.8, while their release behaviour was effectively described by the Korsmeyer-Peppas model. Notably, the novel tube design, which was anticipated to increase the drug release rate, proved the opposite based on the in vitro dissolution study results. Additionally, the use of crospovidone increased DS release rate, whereas croscarmellose sodium decreased it.

Development and in vitro evaluation of donepezil hydrochloride-loaded thermo-responsive polymer grafted molybdenum disulfide nanosheets: Modeling using response surface methodology

Nanocarriers are utilized to deliver bioactive substances in the treatment of neurodegenerative diseases such as Alzheimer's. In this work, we prepared donepezil hydrochloride-loaded molybdenum disulfide modified thermo-responsive polymer as the thermo-responsive nanocarrier. Then, glycine was grafted to the surface of the polymer to improve the targeting and sustained release. The morphology, crystallinity, chemical bonding, and thermal behavior of nanoadsorbent were fully characterized by field emission scanning electron microscopes, energy dispersive X-ray, X-ray diffraction, Fourier-transform infrared spectroscopy, and thermo-gravimetric measurement. Response surface methodology with the central composite design was applied to optimize the sorption key factors such as pH solution (A: 5-9), contact time (B: 10-30 min), and temperature (C: 30-50 °C). Non-linear isotherm modeling confirmed that the sorption of the drug follows the Ferundlich model based on higher correlation coefficient values (R² =0.9923) and lower errors values (root means square errors: 0.16 and Chi-square: 0.10), suggesting a heterogeneous multilayer surface sorption. The non-linear sorption kinetic modeling revealed that the pseudo-second-order kinetic model well-fitted the sorption data of the drug on the nanoadsorbent surface based on higher R² values (R² =0.9876) and lower errors values (root means square errors: 0.05 and Chi-square: 0.02). The in vitro drug release experiment of donepezil hydrochloride shown that about 99.74 % of drug release was found to be occurred at pH= 7.4 (T = 45 °C) within 6 h, whereas about 66.32 % of drug release occurred at pH= 7.4 (T = 37 °C). The release of donepezil hydrochloride from as prepared drug delivery system has shown a sustained release profile, which was fitted to Korsmeyer-Peppas kinetics.

Amination-modified lignin recovery of aqueous phosphate for use as binary slow-release fertilizer

To address the global phosphorus crisis and solve the problem of eutrophication in water bodies, the recovery of phosphate from wastewater for use as a slow-release fertilizer and to improve the slow-release performance of fertilizers is considered an effective way. In this study, amine-modified lignin (AL) was prepared from industrial alkali lignin (L) for phosphate recovery from water bodies, and then the recovered phosphorus-rich aminated lignin (AL-P) was used as a slow-release N and P fertilizer. Batch adsorption experiments showed that the adsorption process was consistent with the Pseudo-second-order kinetics and Langmuir model. In addition, ion competition and actual aqueous adsorption experiments showed that AL had good adsorption selectivity and removal capacity. The adsorption mechanism included electrostatic adsorption, ionic ligand exchange and cross-linked addition reaction. In the aqueous release experiments, the rate of nitrogen release was constant and the release of phosphorus followed a Fickian diffusion mechanism. Soil column leaching experiments showed that the release of N and P from AL-P in soil followed the Fickian diffusion mechanism. Therefore, AL recovery of aqueous phosphate for use as a binary slow-release fertilizer has great potential to improve the environment of water bodies, enhance nutrient utilization and address the global phosphorus crisis.

Influence of HA on Release Process of Anionic and Cationic API Incorporated into Hydrophilic Gel

The properties of sodium hyaluronate (HA), such as hygroscopicity, flexibility, the ability to form hydrogels, as well as biocompatibility and biodegradability, are beneficial for the applications in pharmaceutical technology, cosmetics industry, and aesthetic medicine. The aim of this study was to prepare HA-based hydrogels doped with active pharmaceutical ingredient (API): a cationic drug—lidocaine hydrochloride or anionic drug—sodium. The interaction between the carrier and the implemented active pharmaceutical substances was evaluated in prepared systems by applying viscometric measurements, performing release tests of the drug from the obtained formulations, and carrying out FTIR and DSC. The data from release studies were analyzed using the zero-, first-, and second-order kinetics and Higuchi, Korsmeyer-Peppas, and Hixon-Crowell models. The respective kinetic parameters: the release rate constants, the half-release time and, in the case of the Korsmeyer-Peppas equation, the n parameter were calculated. The variability between the obtained release profiles was studied by calculating the difference (f1) and the similarity factor (f2) as well as employing statistical methods. It was revealed that the incorporation of the drugs resulted in an increase in the viscosity of the hydrogels in comparison to the respective drug-free preparations. The dissolution study showed that not entire amount of the added drug was released from the formulation, suggesting an interaction between the carrier and the drug. The FTIR and DSC studies confirmed the bond formation between HA and both medicinal substances.

f-block MOFs: A Pathway to Heterometallic Transuranics

A novel series of heterometallic f-block-frameworks including the first examples of transuranic heterometallic ²³⁸ U/²³⁹ Pu-metal-organic frameworks (MOFs) and a novel monometallic ²³⁹ Pu-analog are reported. In combination with theoretical calculations, we probed the kinetics and thermodynamics of heterometallic actinide(An)-MOF formation and reported the first value of a U-to-Th transmetallation rate. We concluded that formation of uranyl species could be a driving force for solid-state metathesis. Density of states near the Fermi edge, enthalpy of formation, band gap, proton affinity, and thermal/chemical stability were probed as a function of metal ratios. Furthermore, we achieved 97 % of the theoretical maximum capacity for An-integration. These studies shed light on fundamental aspects of actinide chemistry and also foreshadow avenues for the development of emerging classes of An-containing materials, including radioisotope thermoelectric generators or metalloradiopharmaceuticals.

Design and optimization of a novel herbosomal-loaded PEG-poloxamer topical formulation for the treatment of cold injuries: a quality-by-design approach

The spectrum of cold injuries ranges from frostnip, chilblains to severe frostbite. Cold injuries occur upon prolonged exposure to freezing temperature and are pathologically a combination of ice crystal formation in the tissue resulting in inflammation, thrombosis and ischemia in the extremities, often necessitating limb amputation in extreme cases due to tissue necrosis. Severe forms of frostbite are a cause of major concern to patients as well as the treating physician. Due to the lack of effective treatment modalities and paucity of research on prophylaxis and therapeutics of cold injuries, we developed a novel herbosomal-loaded PEG-poloxamer topical formulation (n-HPTF) employing quality-by-design (QBD) approach. Natural compounds exhibiting potent therapeutic potential for the management of cold injuries were incorporated in novel lipid vesicles (herbosomes) loaded in PEG-poloxamer polymers. The herbosomal formulation effectively creates an occlusion barrier that promotes epithelial regeneration, desmosome scale-up and angiogenesis and thus promotes rapid healing, indicating controlled release of herbosomes. Optimized novel herbosomes showed entrapment efficiency > 90% and < 300 nm mean particle size and in vitro drug permeation of about 2 µg/cm² followed Higuchi's release kinetics. Skin irritancy study on female Sprague-Dawley rats showed no edema or erythema. In vivo bio-efficacy study revealed significant efficacy (p < 0.05) when compared to the standard treatment groups. Graphical abstract presenting the designing and optimization of novel herbosomal-loaded PEG-poloxamer topical formulation (n-HPTF) and predictive model for the in vivo study of the developed n-HPTF on cold injury rat skin model.

An application of CoFe2O4/alginate magnetic beads: drug delivery system of 5-fluorouracil

Magnetic hyperthermia therapy is expected to play an important role in the treatment of more and more cancers. The synergistic effects of using together hyperthermia and cancer drugs have been shown by literature studies to be more effective than either hyperthermia treatment alone or chemotherapy alone. In addition, magnetic materials that can be used as a contrast agent enable magnetic resonance imaging of the tumor, which is also useful in seeing the treatment progress. This study, which was designed for this purpose, occurred in three parts: In the first part, magnetic CoFe2O4/alginate composite beads were prepared and characterized with thermogravimetric analysis (TGA) and scanning electron microscope (SEM). In the second part, the swelling behaviour of magnetic composite beads was investigated at pH 1.2, pH 7.4 and pH 6.8. It was seen that at pH 7.4 and pH 6.8, that is, near neutral pH, CFA swelled by 81.54% and 82.69%, respectively. In the third part, 5-Fluorouracil was encapsulated at the different ratios in CoFe2O4/alginate composite beads, and release experiments were performed at pH 1.2, pH 7.4 and pH 6.8. 5-FU release was calculated with Korsmeyer-Peppas, Higuchi, first-order, and zero-order models. It was seen that the drug release systems prepared were suitable for all kinetic models. Magnetic CoFe2O4/alginate composite bead, which is the drug carrier, was determined to be suitable for controlled release for 5-Fluorouracil.

L-Arginine-Derived Polyamidoamine Oligomers Bearing at Both Ends β-Cyclodextrin Units as pH-Sensitive Curcumin Carriers

The aza-Michael polyaddition of L-arginine and N,N′-methylene-bis-acrylamide gives the biocompatible and easily cell-internalized polyamidoamine ARGO7. By controlled synthesis, two ARGO7 oligomers, namely a trimer and a pentamer, bearing acrylamide terminal units, were obtained as precursors of the β-cyclodextrin-end-terminated oligomers P3 and P5, which have been shown to encapsulate curcumin at both pH 7.4 and 4.5. After lyophilization, P3- and P5-curcumin complexes gave stable water solutions. The apparent solubility of encapsulated curcumin was in the range 20–51 μg mL⁻¹, that is, three orders of magnitude higher than the water solubility of free curcumin (0.011 μg mL⁻¹). The drug release profiles showed induction periods both at pH levels 4.5 and 7.4, suggesting a diffusive release mechanism, as confirmed by kinetic studies. The release rate of curcumin was higher at pH 7.4 than at pH 4.5 and, in both cases, it was higher for the P5 complex. Encapsulated curcumin was more photostable than the free drug. Molecular mechanics and molecular dynamics simulations explain at atomistic level the formation of aggregates due to favorable van der Waals interactions. The drug molecules interact with the external surface of carriers or form inclusion complexes with the β-cyclodextrin cavities. The aggregate stability is higher at pH 4.5.

Vanillin-crosslinked chitosan/ZnO nanocomposites as a drug delivery system for 5-fluorouracil: study on the release behavior via mesoporous ZrO2-Co3O4 nanoparticles modified sensor and antitumor activity

Herein, a series of vanillin-crosslinked chitosan (Vn-CS) nanocomposites (NCs) containing various contents of ZnO nanoparticles (NPs) was prepared and characterized via FTIR spectroscopy, XRD, TGA, SEM and TEM. Changing the weight% of ZnO NPs in the prepared NCs resulted in an improvement in their antibacterial activity against Gram-negative and Gram-positive bacteria strains compared with the unmodified CS, and the encapsulation efficiency of 5-fluorouracil (5-FU) was found to be in the range of 61.4–69.2%. Subsequently, the release of 5-FU was monitored utilizing the mesoporous ZrO₂–Co₃O₄ NPs modified carbon paste sensor via the square-wave adsorptive anodic stripping voltammetry (SW-AdASV) technique. Also, the release mechanism of 5-FU from each NC was studied by applying the zero-order, first-order, Hixson–Crowell and Higuchi models to the experimental results. The cytotoxicity of prepared NCs and 5-FU-encapsulated NCs was evaluated against the HePG-2, MCF-7 and HCT-116 cancer cell lines, in addition to the WI-38 and WISH normal cell lines using the MTT assay. Notably, 5-FU/CV₁₀ NC exhibited the highest antitumor activity towards all tested cancer cell lines and a moderate activity against WI-38 and WISH normal cell lines with IC₅₀ values of 28.02 ± 2.5 and 31.65 ± 2.7 μg mL⁻¹, respectively. The obtained nanocomposites exhibited suitable selectivity with minimum toxicity against normal cells.

Herein, a series of vanillin-crosslinked chitosan (Vn-CS) nanocomposites (NCs) containing various contents of ZnO nanoparticles (NPs) was prepared and characterized via FTIR spectroscopy, XRD, TGA, SEM and TEM.

Process optimization of Ca2+ cross-linked alginate-based swellable microneedles for enhanced transdermal permeability: More applicable to acidic drugs

We describe a swellable microneedle (SMN) consisting of Ca²⁺ cross-linked alginate, which expands the types of natural polymers available for SMN fabrication. After investigation of different fabrication methods, the alginate in situ hydrogel-based SMN with a flat substrate was successfully constructed, whose gelation was triggered by ethylenediaminetetraacetic acid calcium disodium salt and D-(+)-glucono-1,5-lactone. With the addition of polyvinyl alcohol and trehalose, SMN possessed good mechanical properties. The biocompatibility of SMN was demonstrated through the tests of in vitro cytotoxicity and in vivo skin irritation. With the assistance of SMN, the in vitro transdermal delivery efficiencies of drugs were significantly improved throughout 16 h. 3-O-ethyl ascorbic acid (EAA, pH = 4.81) exhibited a cumulative release of up to 83.83 ± 6.30%, which was consistent with zero-order kinetics, while tranexamic acid (TA, pH = 6.90) showed the most significant increase in delivery efficiency, which was consistent with the Higuchi model and Ritger-Peppas model. The SMN remained intact after the 16 h of EAA transdermal delivery, indicating its better suitability for acidic drugs. We believe that this technology has the potential to expand the range of drugs available for transdermal administration as well as the breadth of patient care applications.

Drug delivery systems of CoFe2O4/chitosan and MnFe2O4/chitosan magnetic composites

The study consists of three parts. In the first part, synthesis and characterization of core-shell magnetic composite beads based on chitosan and containing two different magnetic nanoparticles were carried out. The beads were formed from CoFe₂O₄/chitosan and MnFe₂O₄/chitosan. TGA and SEM were used for the characterization of core-shell materials. In the second part, swelling experiments of magnetic beads were performed. In the third part, 5-Fluorouracil was encapsulated at different rates in two different magnetic materials, release experiments were carried out at pH 7.4, pH 6.8, and pH 1.2, and the model of drug release was determined. Korsmeyer-Peppas, Higuchi, first-order, and zero-order models were used for mathematical modeling. Both prepared systems were found to be suitable for controlled release for 5-Fluorouracil.

Factorial design approach to fabricate and optimize floating tablets based on combination of natural polymer and rice bran wax

Background

The aim of the present research work was to fabricate a novel gastroretentive drug delivery system in the form of tablets using a combination of natural polymer and rice bran wax with an intention to control drug delivery and to enhance the gastric residence time of the model drug Famotidine in the gastrointestinal tract.

Results

The results of the preliminary trial batches prepared by using the hot melt granulation technique resulting in six different formulations showed good physicochemical characteristics and tablets conformed to the Pharmacopoeial specifications. Gastroretentive tablets containing natural polymer showed prolonged drug release comparable to Methocel. The optimized formulation (C3) using 32 factorial design showed FLT 27 ± 2.47 s, SI 92.68 ± 1.36% and % CDR 98.89 ± 0.39% at 12 h. The stability studies indicated the stability of the formulation during storage.

Conclusions

It was concluded that the release profile fitted best to zero-order equation with non-Fickian diffusion mechanism of drug release which demonstrates swelling-controlled drug release mechanism. Thus, the formulated tablets have the potential for improved release and gastroretentive properties.

Graphical Abstract

Polymer Architecture Effects on Poly(N,N-Diethyl Acrylamide)-b-Poly(Ethylene Glycol)-b-Poly(N,N-Diethyl Acrylamide) Thermoreversible Gels and Their Evaluation as a Healthcare Material

Thermoreversible gels which transition between liquid-like and solid-like states when warmed have enabled significant novel healthcare technologies. Poly(N,N-diethyl acrylamide) (PDEA) is a thermoresponsive polymer which can be used as a trigger to form thermoreversible gels, however its use in these materials is limited and crucial design principles are unknown. Herein ABA copolymers with the structure PDEA-b-poly(ethylene glycol) (PEG)-b-PDEA are synthesized to give four block copolymers with varied molecular weight of PDEA and PEG blocks. Rheometry on solutions of the block copolymers reveals that high molecular weight PEG blocks are required to form thermoreversible gels with predominantly solid-like behavior. Furthermore, small-angle X-ray scattering elucidates clear differences in the nanostructure of the copolymer library which can be linked to distinct rheological behaviors. A thermoreversible gel formulation based on PDEA (20 kDa)-b-PEG (10 kDa)-b-PDEA (20 kDa) is designed by optimizing the polymer concentration and ionic strength. It is found that the gel is mucoadhesive, stable, and non-toxic, as well as giving controlled release of a hydrophobic drug. Overall, this study provides insight into the effect of polymer architecture on the nanostructure and rheology of PDEA-b-PEG-b-PDEA and presents the development of a highly functional thermoreversible gel with high promise for healthcare applications.

The fabrication of a highly efficient hydrogel based on a functionalized double network loaded with magnesium ion and BMP2 for bone defect synergistic treatment

Although the use of bioactive ions and proteins are crucial for bone defect repair, delivering them in a stable and controlled manner remains challenging. To achieve controlled delivery of osteogenic active factor, we developed a novel double network (DN) hydrogel capable of co-delivering Mg²⁺ ions and BMP2 in a controlled localized manner. This DN hydrogel was composed of poly (acrylamide) and chitosan, in which the poly (acrylamide) was cross-linked via covalent bond and the chitosan was grafted using bisphosphonate (BP) to form metal coordination bonds with Mg²⁺ ions. Due to this dynamic dissociation and re-association of the "BP-Mg²⁺" coordination bond, it was possible to deliver Mg²⁺ ions in a stable and controlled manner. Additionally, the obtained DN hydrogel exhibited an effective tensile strength (0.62 MPa), perfect stretchability (973% fracture strain), and good creep and recovery properties due to the dynamic cross-linking effect of "BP-Mg²⁺". Additionally, the hydrogel could synergistically promote the proliferation and differentiation of mouse embryo osteoblast precursor cells (MC3T3-E1 cells) in vitro via the BMP2/Wnt pathway. In the skull defect rat model, this positive delivery government of Mg²⁺ ions and BMP2 synergistically accelerated bone regeneration. In conclusion, this dynamic cross-linked hydrogel containing Mg²⁺ ions established a new platform for the sustained release of osteogenesis factor and accelerated the bone regeneration process.

Ligand Decorated Primaquine Loaded Nanocarriers for Liver Targeting for Triggered Anti-Malarial Activity

OBJECTIVE

The aim of the current research is to formulate a nano delivery system for effective delivery of primaquine for liver targeting to achieve the potential anti-malarial activity. Another objective of current development is to formulate a lactobionic acid conjugated polyphosphazene based nano delivery of primaquine for liver targeting to distinguish anti-malarial activity.

METHOD

The particle size, entrapment efficiency, in-vitro drug release pattern, hepatotoxicity, MTT assay, erythrocyte toxicity assay, histopathology study, HepG2 cell uptake study, anti-- malarial study, and organ-distribution was also carried out to estimate the activity and potential features of a nanoparticle system.

RESULTS

The results obtained from the above analysis justify the efficiency and effectiveness of the system. The NMR studies confirm the conjugation pattern and the TEM represents the spherical morphological features of nanoparticles. The controlled release pattern from the in-vitro release study was observed and found to be 73.25% of drug release in 20 hrs and in the nano-size range (61.6± 1.56 nm) by particle size analysis.SGOT level, SGPT, ALP, and Parasitemia level of optimized drug-loaded PEGylated lactobionic acid conjugated polyphosphazene derivatized nanoparticles (FF) was found to lie in the safe range, showing that the formulation is non-toxic to the liver. Primaquine drug-loaded PEGylated lactobionic acid conjugated polyphosphazene polymeric nanoparticles showed higher cell uptake on HepG2 cell lines as compared to the drug-loaded in PEGylated polyphosphazene polymeric nanoparticles and plain drug.Percentage cell viability of drugloaded PEGylated lactobionic acid conjugated polyphosphazene derivatized nanoparticles was decreased by enhancing the concentration of prepared nanoparticle system accessed by MTT assay.

CONCLUSION

From the studies, it can be concluded that the optimized formulation of drug-loaded PEGylated lactobionic acid conjugated polyphosphazene derivatized nanoparticles showed high liver targeting, least toxicity to the liver, controlled release of the drug, higher anti-malarial activity against hepatocytes at a low dose, more effectiveness, and can be treated as a potential candidate for anti-malarial therapy.

Innovative Eco-Friendly Hydrogel Film for Berberine Delivery in Skin Applications

Hydrogel formulations (masks or patches, without tissue support) represent the new frontier for customizable skin beauty and health. The employment of these materials is becoming popular in wound dressing, to speed up the healing process while protecting the affected area, as well as to provide a moisturizing reservoir, control the inflammatory process and the onset of bacterial development. Most of these hydrogels are acrylic-based at present, not biodegradable and potentially toxic, due to acrylic monomers residues. In this work, we selected a new class of cellulose-derived and biodegradable hydrogel films to incorporate and convey an active compound for dermatological issues. Films were obtained from a combination of different polysaccharides and clays, and berberine hydrochloride, a polyphenolic molecule showing anti-inflammatory, immunomodulatory, antibacterial and antioxidant properties, was chosen and then embedded in the hydrogel films. These innovative hydrogel-based systems were characterized in terms of water uptake profile, in vitro cytocompatibility and skin permeation kinetics by Franz diffusion cell. Berberine permeation fitted well to Korsmeyer-Peppas kinetic model and achieved a release higher than 100 µg/cm2 within 24 h. The latter study, exploiting a reliable skin model membrane, together with the biological assessment, gained insights into the most promising formulation for future investigations.

Preparation, Properties and Potential of Carrageenan-Based Hard Capsules for Replacing Gelatine: A Review

Intense efforts to develop alternative materials for gelatine as a drug-delivery system are progressing at a high rate. Some of the materials developed are hard capsules made from alginate, carrageenan, hypromellose and cellulose. However, there are still some disadvantages that must be minimised or eliminated for future use in drug-delivery systems. This review attempts to review the preparation and potential of seaweed-based, specifically carrageenan, hard capsules, summarise their properties and highlight their potential as an optional main component of hard capsules in a drug-delivery system. The characterisation methods reviewed were dimensional analysis, water and ash content, microbial activity, viscosity analysis, mechanical analysis, scanning electron microscopy, swelling degree analysis, gel permeation chromatography, Fourier-transform infrared spectroscopy and thermal analysis. The release kinetics of the capsule is highlighted as well. This review is expected to provide insights for new researchers developing innovative products from carrageenan-based hard capsules, which will support the development goals of the industry.

Controlled Release of Flavor Substances from Sesame-Oil-Based Oleogels Prepared Using Biological Waxes or Monoglycerides

The flavor substances in sesame oil (SO) are volatile and unstable, which causes a decrease in the flavor characteristics and quality of SO during storage. In this study, the effect of gelation on the release of flavor substances in SO was investigated by preparing biological waxes and monoglycerides oleogels. The results showed that the release of flavor substances in SO in an open environment is in accordance with the Weibull equation kinetics. The oleogels were found to retard the release of volatiles with high saturated vapor pressures and low hydrophobic constants in SO. The release rate constant k value of 2-methylpyazine in BW oleogel is 0.0022, showing the best retention effect. In contrast, the addition of gelling agents had no significant retention effect on the release of volatiles with low saturated vapor pressures or high hydrophobic constants in SO, and even promoted the release of these compounds to some extent. This may be due to the hydrophilic structural domains formed by the self-assembly of gelling agents, which reduces the hydrophobicity of SO. This work provides a novel approach for retaining volatile compounds in flavored vegetable oils. As a new type of flavor delivery system, oleogels can realize the controlled release of volatile compounds.

An Integrated Biophysical Model for Predicting the Clinical Pharmacokinetics of Transdermally Delivered Compounds

The delivery of therapeutic drugs through the skin is a promising alternative to oral or parenteral delivery routes because dermal drug delivery systems (D³S) offer unique advantages such as controlled drug release over sustained periods and a significant reduction in first-pass effects, thus reducing the required dosing frequency and level of patient noncompliance. Furthermore, D³S find applications in multiple therapeutic areas, including drug repurposing. This article presents an integrated biophysical model of dermal absorption for simulating the permeation and absorption of compounds delivered transdermally. The biophysical model is physiologically/biologically inspired and combines a holistic model of healthy skin with whole-body physiology-based pharmacokinetics through dermis microcirculation. The model also includes the effects of chemical penetration enhancers and hair follicles on transdermal transport. The model-predicted permeation and pharmacokinetics of select compounds were validated using in vivo data reported in the literature. We conjecture that the integrated model can be used to gather insights into the permeation and systemic absorption of transdermal formulations (including cosmetic products) released from novel depots and optimize delivery systems. Furthermore, the model can be adapted to diseased skin with parametrization and structural adjustments specific to skin diseases.

Demonstration of Advanced Data Mining Tools for Optimization of Pellets Employing Modified Extrusion-pelletization Technique

Background:

The multi particulate drug delivery system is preferred due to its numerous advantages but the batch to batch consistency and to achieve desired physical properties are the major challenges in the formulation of such dosage form.

Objective:

The objective of the present study was to explore the concept of quality by design for the development of galantamine HBr controlled release pellets using a modified palletization technique.

Methods:

Compritol 888 and Ethocel were chosen as hydrophobic release retardants, while Avicel was chosen as pelletization aid. A compatibility study was conducted between the drug and excipients. Drug loaded extrudes were prepared by using a mixture of isopropyl alcohol, and dichloromethane. Before converting the wet extrudes into pellets, pregelatinized starch was sprinkled on them to improve the physical properties of the pellets. The pellets were characterized for size, shape, and flow. The critical evaluation parameter was the drug dissolution pattern in distilled water. The dissolution data were treated with advanced data mining techniques. The in-vivo profile was predicted employing pharmacokinetic parameters of the drug and in-vitro drug release data of optimized batch pellets.

Results:

The failure mode and effect analysis revealed that the amount of Compritol 888 ATO and Ethocel were the most critical formulation parameters. The results of FTIR and DSC revealed compatibility between the drug and the excipients. The spherical pellets exhibited good flow. The drug dissolution studies of the batches, prepared according to the central composite design, revealed modified drug release. Multiple regression analysis and analysis of variance were performed to identify statistically significant factors. Contour plots demonstrated the impact of the amount of Compritol 888 and ethyl cellulose. The Design-Expert software was used to identify optimized formulation. The predicted in-vivo plasma concentration-time profile revealed the modified drug release up to 12h.

Conclusions:

Compritol and Ethocel were able to retard the drug release up to 12 hrs in distilled water. The innovative finding of this study is the use of a dry binder (pregelatinized starch) to improve the characteristics of pellets. Other dry binders are expected to show a similar effect. The newer processing technique can be of use in the industry.

A garlic oil-based organo-hydrogel for use in pH-sensitive drug release

In this study, six different organo-hydrogels containing agar-glycerol (AG)-based garlic oil (GO) were synthesized using two different crosslinkers (N,N, methylenebisacrylamide (MBA), glutaraldehyde (GA)) to ensure the controlled release of ceftriaxone (Ce) and carboplatin (Cp). Synthesized organo-hydrogels were characterized by FT-IR. Afterward, swelling behaviors were investigated in DI, tap water, ethanol, acetone, ethanol/DI water (1:1), acetone/DI water (1:1) and gasoline environments and different pH. As a result of hemolysis, blood clotting and antioxidant analysis, organo-hydrogels have been shown to have blood compatibility and antioxidant properties. Ce and Cp release properties of the prepared organo-hydrogels were also determined. The highest Ce release rate was obtained to be 37.8% for p (AG-g-GO)³ at pH 8.0 after 7 days. However, the highest Cp release rate was found to be 95.4% for p (AG-g-GO)³ at pH 7.4 after 1 day.

Green Synthesis of Thermo-Responsive Hydrogel from Oil Palm Empty Fruit Bunches Cellulose for Sustained Drug Delivery

Drug delivery is a difficult task in the field of dermal therapeutics, particularly in the treatment of burns, wounds, and skin diseases. Conventional drug delivery mediums have some limitations, including poor retention on skin/wound, inconvenience in administration, and uncontrolled drug release profile. Hydrogels able to absorb large amount of water and give a spontaneous response to stimuli imposed on them are an attractive solution to overcome the limitations of conventional drug delivery media. The objective of this study is to explore a green synthesis method for the development of thermo-responsive cellulose hydrogel using cellulose extracted from oil palm empty fruit bunches (OPEFB). A cold method was employed to prepare thermo-responsive cellulose hydrogels by incorporating OPEFB-extracted cellulose and Pluronic F127 (PF127) polymer. The performance of the synthesized thermo-responsive cellulose hydrogels were evaluated in terms of their swelling ratio, percentage of degradation, and in-vitro silver sulfadiazine (SSD) drug release. H8 thermo-responsive cellulose hydrogel with 20 w/v% PF127 and 3 w/v% OPEFB extracted cellulose content was the best formulation, given its high storage modulus and complex viscosity (81 kPa and 9.6 kPa.s, respectively), high swelling ratio (4.22 ± 0.70), and low degradation rate (31.3 ± 5.9%), in addition to high t50% value of 24 h in SSD in-vitro drug release to accomplish sustained drug release. The exploration of thermo-responsive cellulose hydrogel from OPEFB would promote cost-effective and sustainable drug delivery system with using abundantly available agricultural biomass.

Application of Poly (Agar-Co-Glycerol-Co-Sweet Almond Oil) Based Organo-Hydrogels as a Drug Delivery Material

In this study, it was aimed to investigate the synthesis, characterization and drug release behaviors of organo-hydrogels containing pH-sensitive Agar (A), Glycerol (G), Sweet Almond oil (Wu et al. in J Mol Struct 882:107-115, 2008). Organo-hydrogels, which contained Agar, Glycerol and different amounts of Sweet Almond oil, were synthesized via the free-radical polymerization reaction with emulsion technique using glutaraldehyde or methylene bis acrylamide crosslinkers. Then, the degree of swelling, bond structures, blood compatibility and antioxidant properties of the synthesized organo-hydrogels were examined. In addition, Organo-hydrogels which loaded with Ceftriaxone and Oxaliplatin were synthesized with the same polymerization reaction and release kinetics were investigated. In vitro release studies were performed at media similar pH to gastric fluid (pH 2.0), skin surface (pH 5.5), blood fluid (pH 7.4) and intestinal fluid (pH 8.0), at 37 °C. The effects on release of crosslinker type and sweet almond oil amount were investigated. Kinetic parameters were determined using release results and these results were applied to zero and first-order equations and Korsmeyer-Peppas and Higuchi equations. Diffusion exponential was calculated for drug diffusion of organo-hydrogels and values consistent with release results were found.

Evaluation of wound healing potential of new composite liposomal films containing coenzyme Q10 and d-panthenyl triacetate as combinational treatment

Conventional formulations can not achieve wound healing efficiently and fail to accelerate wound regeneration. To overcome these problems, it was planned to develop nanoformulations that perform a positive effect on the wound healing duration and are suitable for topical use. In this study, liposomal film formulations that encapsulated d-panthenyl triacetate (PTA) and coenzyme Q10 (CoQ10) were optimized by using response surface methodology (RSM) and were analyzed for their wound healing efficacy and cytotoxicity on fibroblast (CCD1079 Sk) and keratinocyte (HEKa) cells. Swelling index, puncture strength, and puncture deformation values, which were choosen as dependent variables for the liposomal film formulation were found as 556.9% ± 21.3, 3.98 ± 0.98 N/mm², and 6.57% ± 1.12, respectively. Cumulative release of 65.32% for PTA and 12.23% for CoQ10 was obtained after 24 hours of in vitro release study in sink conditions. The in vitro cytotoxicity and wound healing assay results suggested that optimum formulation could be used safely on fibroblast and keratinocyte cells and provided wound closure entirely after 24 h. Consequently, the optimum liposomal film containing PTA and CoQ10 formulations could be proposed as an innovative approach in wound healing treatment, considering their release, mechanical properties, stability, and effectiveness.

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

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

Synthesis and characterization of novel organo-hydrogel based agar, glycerol and peppermint oil as a natural drug carrier/release material

The very recent Covid-19 pandemic has made the need to understand biocompatible polymers as support material in drug delivery systems and controlled release clearer, especially for organo-hydrogels. This study aims to synthesize various new polymeric materials called gels, hydrogels, and organo-hydrogels according to the monomer used and to investigate their use as drug release systems. The agar-glycerol (AG) pair was used to synthesize the polymers, N, N, methylene bisacrylamide (MBA, m) and glutaraldehyde (GA, g) were used as cross-linkers and peppermint oil (PmO) was included to obtain the organo-hydrogels. Therefore, one AG gel and two p (AG-m) and p (GA-g) hydrogels were synthesized within the scope of the study. Six different organo-hydrogels based on p(AG-m-PmO) or p (AG-g-PmO) were also synthesized by varying the amount of peppermint oil. Paracetamol and carboplatin were selected as the sample drugs. Synthesized gels, hydrogels and organo-hydrogels were characterized by FTIR and SEM analysis. Additionally, swelling behaviors of the synthesized gels were investigated in different media (ID water, tap water, ethanol, acetone, ethanol/ID water (1:1), acetone/ID water (1:1) and gasoline) and at different pHs. Moreover, it was determined that organo-hydrogels were blood compatible and had antioxidant properties based on hemolysis, blood clotting and antioxidant analysis. Therefore, the release of paracetamol (a known antipyretic-painkiller, recommended and used in the treatment of Covid-19) and carboplatin (widely used in cancer treatment) were studied. Evidently, as the amount of PMO oil increases, the -OH groups in organo-hydrogels will increase and the chemical and physical bonding rates will increase; therefore it was observed that increasing peppermint oil in the organo-hydrogels structure to 0.3 mL stimulated the release of the drugs. For instance, maximum paracetamol release amount from p(AG-g-PmO) and p(AG-m-PmO) organo-hydrogels was calculated to be 72.3% at pH 7.4 and 69.8% at pH 2.0, respectively. The maximum carboplatin release amount from p(AG-g-PmO) and p(AG-m-PmO) organo-hydrogels was calculated to be 99.7% at pH 7.4 and 100% at pH 7.4, respectively. It was concluded that the synthesized organo-hydrogels might easily be used as drug carrier and controlled drug release materials.

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Novel organo-hydrogels were synthesized using agar, glycerol and peppermint oil for drug carrier and controlled release.

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Biocompatibility and antioxidant properties of organo-hydrogels were investigated.

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Covid-19 and cancer sensitive drugs (Paracetamol and Carboplatin) were accomplished.

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The superior properties of the synthesized organo-hydrogels make them useful in biomedical, pharmaceutical and drug delivery systems applications.