Clarithromycin highly-loaded gastro-floating fine granules prepared by high-shear melt granulation can enhance the efficacy of Helicobacter pylori eradication

Bioadhesive behaviors of HPMC E5: comparative analysis of various techniques, histological and human radiological evidence

Enhancing drug residence duration within the stomach offers distinct advantages for both localized and systemic effects. Numerous strategies have been proposed to extend drug residence time, with mucoadhesive polymers being a notable avenue. In this context, hydroxypropyl methylcellulose E5 has been employed as both a binding agent for granulating contrast metal powder and a mucoadhesive polymer, spanning various concentrations. The in vitro bioadhesion strength of the formulated tablets was gauged against the stomach lining of rabbits, for the quantification of bioadhesive forces. The temporal aspect of bioadhesion was evaluated through two approaches: one centered on gastric fluid dynamics and another proffered by the researchers, focusing on gastric wall kinetics. The results divulged a decline in bioadhesion force concomitant with high polymer concentrations. Histological examination of stained stomach sections revealed mucosal perturbations within the rabbit stomach. These disruptions exhibited an escalating trend in conjunction with elevated polymer concentrations, culminating in extensive disturbance at a 7.5% polymer concentration. The outcomes unveiled a direct relationship between polymer concentration increments and extended contact time. Subsequent radiological tracking of contrast metal behavior within a mature human stomach indicated a residence time of 6 h due to the entrapment of displaced components at disparate locations.

Preparation and Characterization of Patch Loaded with Clarithromycin Nanovesicles for Transdermal Drug Delivery

Clarithromycin (CLR), categorized as a Biopharmaceutical Classification System class II drug, has several gastrointestinal tract side effects and an extremely unpalatable bitter taste. The current study aimed to design transdermal patch-embedded CLR niosomes to overcome the aforementioned CLR-related challenges. Various niosomal formulations were successfully fabricated and characterized for their morphology, size, in vitro release, and antimicrobial efficacy. Subsequently, the CLR niosomes were loaded into transdermal patches using the solvent casting method. The polydispersity index of the niosomes ranged from 0.005 to 0.360, indicating the uniformity of the niosomes. The encapsulating efficiency (EE)% varied from 12 to 86%. The optimal Chol: surfactant ratio for drug release was found to be 0.5:1. In addition, the encapsulation of CLR into niosomal nanovesicles did not reduce the antibacterial activity of the CLR. The niosomal patch had a significantly higher permeability coefficient of CLR than the conventional patch. In addition to that, a shear-thinning behavior was observed in the niosomal gels before loading them into a niosomal patch. The flux (Jss) of the niosomal patch was significantly higher than the conventional patch by more than 200 times. In conclusion, niosome-based transdermal patches could be a promising method for the transdermal drug delivery of class II drugs and drugs experiencing GIT side effects.

Metronidazole Based Floating Bioadhesive Drug Delivery System for Potential Eradication of H. pylori: Preparation and In Vitro Characterization

Metronidazole has the potential to produce local stomach specific action in order to treat Helicobacter pylori induced peptic ulcer disease. The current project executes the development of osmotically controlled bioadhesive metronidazole loaded effervescent floating tablets with optimized floating and swelling behavior. Direct compression technique was used to prepare the tablets. The designed formulations exhibited physico-chemical properties within acceptable optimum limits as per pharmacopeial requirements. The results of tablet floating studies revealed that all formulations, except F1 and F5, had good buoyancy characteristics (TFT > 12 h except F2 and F8 with TFT of 6 h). Formulation F2 containing guar gum in higher concentration with carbopol and formulation F8 containing guar gum in 50% decreased concentration in combination with HPMC and carbopol had enhanced FLT appreciably, with least TFT as compared to formulations F3, F4, and F6 (ANOVA; p ≤ 0.05). Formulation batches of F3, F4, and F6 exhibited appreciable FLT as well as TFT and were optimized formulations. Out of the above mentioned optimized batches, F4 and F6 formulations showed low FLT (4 and 5 s respectively). The results of the swelling study indicated a proportionate increase in the swelling index with increase in time. A significantly higher swelling ratio was found with formulation F6 and F4 compared with that of F7 and F8 (ANOVA; p ≤ 0.05). Additionally, the impact of pH change, agitational intensity, as well as increasing concentration of NaCl was investigated on drug release. It was observed that agitational intensity had no effect on drug release rate while increasing concentration of NaCl produced an increased drug release from the dosage form as compared to the drug release exhibited by the formulations in the absence of NaCl. Overall, this project could have valuable contribution in the fabrication of metronidazole loaded effervescent floating tablets. Gastro-retentive systems are expected to enhance local stomach specific action of anti H. pylori agents based on their buoyancy and swelling behavior.

Preparation of clarithromycin floating core-shell systems (CSS) using multi-nozzle semi-solid extrusion-based 3D printing

Matrix erosion is unavoidable during the release of poorly soluble drugs from gastric floating delivery system (GFDDS), which shortens the floating time and diminishes drug release. We fabricated a core-shell system (CSS) consisting of a low-density drug-loaded shell and a floating core using multi-nozzle semi-solid extrusion (SSE) 3D printing technology. The clarithromycin (CAM) loading capacity of the shell was 81.7%. The floating core paste provided structural support during printing and formed a hollow structure in CAM CSS, which increased the buoyancy in the early stage of drug release. In addition, the floating core had numerous micro-airbags that swelled when the solution penetrated the core, and generated CO₂. The micro-airbag structure and CO₂ generation further increased the buoyancy of CSS. The CAM CSS achieved 74.5% (w/w) drug loading, 8 h sustained release, and immediate and prolonged floating (>10 h). This structure of CSS and floating core provide a novel perspective for constructing a stable gastric floating drug delivery system.

Preparation of High-Drug-Loaded Clarithromycin Gastric-Floating Sustained-Release Tablets Using 3D Printing

The high-drug-loaded sustained-release gastric-floating clarithromycin (CAM) tablets were proposed and manufactured via semisolid extrusion (SSE)-based 3D printing. The physical and mechanical properties, such as dimensions, weight variation, friability, and hardness, were accessed according to the quality standards of Chinese Pharmacopoeia (Ch.P). The interactions among the drug-excipients were evaluated via differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) techniques. Next, the rheological properties of the paste and the effect of the excipients and solvents were evaluated. Finally, a very high drug-loading of up to 81.7% (w/w) with the sustain release time of 8 h (125 mg) and 12 h (250 mg) was achieved. The results revealed the potential of SSE for achieving a high drug loading and identified the suitable properties of the paste for SSE-based 3D printing.

Analysis of available surface area can predict the long-term dissolution profile of tablets using short-term stability studies

Generally, since at least 6 months are usually needed for accelerated testing of tablet at 40 °C/75% relative humidity (RH), it would be crucial important to predict the dissolution profiles during long-term storage period by using samples stored with shorter periods such as 3 months. In this study, we developed a new method for predicting changes in dissolution from tablets during long-term storage-based changes in the available surface area [S (t)]. In addition, we discussed the dissolution behavior and mechanisms using S (t). The results revealed drastic delays in dissolution in samples stored at 40 °C/75% RH for 7 weeks. Considering changes of S (t) patterns, this delay was derived from changes of the tablet surface. New parameters, namely T_22.1 and T_63.2, calculated from the S (t) profile tended to increase with an increased duration of testing. Concerning the long-term prediction model using short-term data, a nonlinear model was deemed appropriate because good agreement was observed between the value predicted using the model and the measured value for samples stored at 40 °C/75% RH for 6 months. Therefore, using the new evaluation method based on S (t), we can predict changes in dissolution during long-term storage using short-term methods.

Plant exine capsules based encapsulation strategy: A high loading and long-term effective delivery system for nobiletin

The properties of high loading capacity and long-term absorption are of great significance in the field of nutraceuticals or drugs delivery. Herein, we developed an innovative method to achieve these expected effects using plant exine capsules, a kind of natural pollen grains, which could provide large internal cavities for loading and robust exine against harsh conditions. In our work, we firstly made a soluble mixture of glycerol monostearate (GM) and nobiletin (NOB) inside the cavities of plant exine capsules by ultrasound with high temperature to obtain a supersaturated state of NOB, which could be characterized by XRD, DSC and FTIR. After that, the loaded capsules were cooled to room temperature. Alginate hydrogels were then selected for encapsulating and further controlling NOB release in simulated gastric and intestinal conditions. As a result, it demonstrated that our approach was able to reach an extremely high NOB loading capacity of 770 ± 40 mg/g using sunflower pollen grains (SPGs). Meanwhile, the existence of GM, SPGs and alginate hydrogels all retarded the release of the NOB synergistically, thus taking a slow release effect in the stomach while a long-term effective absorption in the intestine. Taken together, our processing method of encapsulating hydrophobic nutraceuticals provides an important insight for broadening the applications of nutraceutical or drug encapsulation and delivery.

Twin-screw extrusion of sustained-release oral dosage forms and medical implants

Most of published reviews of twin-screw extrusion focused on its application for enhancing the bioavailability of amorphous solid dispersions while few of them focused on its use for manufacturing sustained-release oral dosage forms and medical implants, despite the considerable interest and success this process has garnered both in academia and in the pharmaceutical industry. Compared to conventional batch processing, twin-screw extrusion offers the advantages of continuous processing and the ability to prepare oral dosage forms and medical implants that have unique physicochemical and drug release attributes. This review provides an in-depth analysis of the formulation composition and processing conditions of twin-screw extrusion and how these factors affect the drug release properties of sustained-release dosage forms. This review also illustrates the unique advantages of this process by presenting case studies of a wide variety of commercial sustained-release products manufactured using twin-screw extrusion.

Development of genipin-crosslinked fucoidan/chitosan-N-arginine nanogels for preventing Helicobacter infection

AIM

This study aims to validate the anti-Helicobacter pylori efficacy of amoxicillin-loaded nanoparticles and nanogels with pH-responsive and site-specific drug release properties against H. pylori infection.

MATERIALS & METHODS

Genipin-crosslinked low molecular weight fucoidan/chitosan-N-arginine nanogels (FCSA) were prepared for targeted delivery of amoxicillin to the site of H. pylori infected AGS gastric epithelial cells.

RESULTS

The negatively charged nanogels (n-FCSA) adhered to H. pylori and exhibited pH-responsive drug release property to reduce cytotoxic effects in H. pylori infected AGS cells.

CONCLUSION

These in vitro findings suggest that n-FCSA nanogels are potential carriers for H. pylori specific delivery of antibacterial agents, and provide the basis for further studies on the clinical use of the nanogels.