Floating Drug Delivery Systems: An Emerging Trend for the Treatment of Peptic Ulcer

Design and Evaluation of New Gel-Based Floating Matrix Tablets Utilizing the Sublimation Technique for Gastroretentive Drug Delivery

A gel-based floating matrix tablet was formulated and evaluated using the sublimation technique to enhance gastroretentive drug delivery. Anhydrous theophylline was employed as the active pharmaceutical ingredient, combined with sublimation agents and hydroxypropyl methylcellulose as the gel-forming polymer. The resulting tablets exhibited high porosity, immediate floatation, and sustained buoyancy for over 8 h. Optimization of the floating behavior and drug release profiles was achieved by adjusting the viscosity of and hydroxypropyl methylcellulose and the concentration of sublimation agents, specifically ammonium carbonate and menthol. These agents were selected for their effectiveness in creating a porous structure, thus reducing tablet density and enhancing floatation. Higher HPMC viscosity resulted in increased floating force, slower drug release, and improved swelling properties due to a slower erosion rate. A critical assessment of the balance between tablet porosity, mechanical strength, and drug release kinetics indicates that ammonium carbonate provided superior tablet hardness and lower friability compared to menthol, favoring a controlled release mechanism. The release dynamics of theophylline were best described by the anomalous (non-Fickian) diffusion model, suggesting a combined effect of diffusion and erosion. This research advances the development of gastroretentive drug delivery systems, highlighting the potential of sublimation-based floating matrix tablets for sustained drug release.

Advanced polymers and recent advancements on gastroretentive drug delivery system; a comprehensive review

Oral route of drug administration is typically the initial option for drug administration because it is both practical and affordable. However, major drawback of this route includes the release of drug at a specified place thus reduces the bioavailability. This could be overcome by utilising the gastroretentive drug delivery system (GRRDS). Prolonged stomach retention improves bioavailability and increases solubility for medicines that are unable to dissolve in high pH environments. Many recent advancements in the floating, bio adhesive, magnetic, expandable, raft forming and ion exchange systems have been made that had led towards advanced form of drug delivery. From the past few years, floating drug delivery system has been most commonly utilised for the delivery of drug in a delayed manner. Various polymers have been utilised for manufacturing of these systems, including alginates, chitosan, pectin, carrageenan's, xanthan gum, hydroxypropyl cellulose, carbomer, polyethylene oxide and sodium carboxy methyl cellulose. Chitosan, pectin and xanthan gum have been found to be most commonly used polymers in the manufacturing of drug inclusion complex for gastroretentive drug delivery. This study aimed to define various types and advanced polymers as well as also highlights recent advances and future perspectives of gastroretentive drug delivery system.

Assessing the Synergistic Activity of Clarithromycin and Therapeutic Oils Encapsulated in Sodium Alginate Based Floating Microbeads

We developed alginate-based floating microbeads of clarithromycin with therapeutic oils for the possible eradication of Helicobacter pylori (H. pylori) infections by enhancing the residence time of the carrier at the site of infection. In pursuit of this endeavor, the alginate was blended with hydroxy propyl methyl cellulose (HPMC) as an interpenetrating polymer to develop beads by ionotropic gelation using calcium carbonate as a gas generating agent. The developed microbeads remained buoyant under gastric conditions for 24 h. These microbeads initially swelled and afterwards decreased in size, possibly due to the erosion of the polymer. Furthermore, swelling was also affected by the type of encapsulated oil, i.e., swelling decreased with increasing concentrations of eucalyptus oil and increased with increasing concentrations of oleic acid. Antibacterial assays of the formulations showed significant antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli); these assays also showed synergistic activity between clarithromycin and therapeutic oils as evident from the higher zone of inhibition of the microbeads as compared to the pure drug and oils. Scanning electron microscopy (SEM) images revealed a smoother surface for oleic acid containing the formulation as compared to eucalyptus oil containing the formulation. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed the development of a stable formulation, while Fourier transform infrared spectrophotometry (FTIR) studies did not reveal any interaction between the polymers and the active ingredients. Optimized formulations (CLM3 and CLM6) were designed to release the drug in a controlled manner in gastric media by Fickian diffusion. Conclusively, the developed microbeads are a promising carrier to overcome the narrow therapeutic index and low bioavailability of clarithromycin, while the presence of therapeutic oils will produce synergistic effects with the drug to eradicate infection effectively.

Preparation and Characterization of Controlled-Release Floating Bilayer Tablets of Esomeprazole and Clarithromycin

Controlled-release effervescent floating bilayer tablets reduce dosage frequency and improve patient compliance with enhanced therapeutic outcomes. Generally, two different tablets of clarithromycin and esomeprazole, respectively, are given for the treatment of Helicobacter pylori infection and it might be worth incorporating both in a single tablet. In the current study, controlled-release floating bilayer tablets of clarithromycin and esomeprazole (F1−F4) were developed with different rates of polymeric materials by a direct compression method. During the formulation, Fourier-transform infrared spectroscopy (FTIR) analysis was performed for possible interactions between drugs and excipients. No interactions between drugs and excipients were noted. Moreover, the bilayer tablets’ thickness, diameter, friability, hardness, weight variation, dissolution, and percent purity were found within the acceptable limits. The floating lag time and total floating time of all formulations were found to be < 25 s and 24 h, respectively. The release of both the clarithromycin and esomeprazole started at the same time from the controlled-release floating bilayer tablets by anomalous non-Fickian diffusion, and the polymeric materials extended the drug release rate up to 24 h. In the case of F1, the results approached ideal zero-order kinetics. The dissolution profiles of the tested and reference tablet formulations were compared, but no significant differences were observed. It can be concluded that such controlled-release effervescent floating bilayer tablets can be efficiently used in clinical practice to reduce dosage frequency and increase patient compliance with continuous drug release for 24 h, which ultimately might enhance therapeutic efficacy.

Development of Composite, Reinforced, Highly Drug-Loaded Pharmaceutical Printlets Manufactured by Selective Laser Sintering-In Search of Relevant Excipients for Pharmaceutical 3D Printing

3D printing by selective laser sintering (SLS) of high-dose drug delivery systems using pure brittle crystalline active pharmaceutical ingredients (API) is possible but impractical. Currently used pharmaceutical grade excipients, including polymers, are primarily designed for powder compression, ensuring good mechanical properties. Using these excipients for SLS usually leads to poor mechanical properties of printed tablets (printlets). Composite printlets consisting of sintered carbon-stained polyamide (PA12) and metronidazole (Met) were manufactured by SLS to overcome the issue. The printlets were characterized using DSC and IR spectroscopy together with an assessment of mechanical properties. Functional properties of the printlets, i.e., drug release in USP3 and USP4 apparatus together with flotation assessment, were evaluated. The printlets contained 80 to 90% of Met (therapeutic dose ca. 600 mg), had hardness above 40 N (comparable with compressed tablets) and were of good quality with internal porous structure, which assured flotation. The thermal stability of the composite material and the identity of its constituents were confirmed. Elastic PA12 mesh maintained the shape and structure of the printlets during drug dissolution and flotation. Laser speed and the addition of an osmotic agent in low content influenced drug release virtually not changing composition of the printlet; time to release 80% of Met varied from 0.5 to 5 h. Composite printlets consisting of elastic insoluble PA12 mesh filled with high content of crystalline Met were manufactured by 3D SLS printing. Dissolution modification by the addition of an osmotic agent was demonstrated. The study shows the need to define the requirements for excipients dedicated to 3D printing and to search for appropriate materials for this purpose.

Gastric floating tablet improves the bioavailability and reduces the hypokalemia effect of gossypol in vivo

Gossypol (Gos) is a natural polyphenolic compound that has shown a number of valuable biological properties such as antifertility, antioxidation, and antitumor activities. However, the clinical application of Gos has been hindered by its notable adverse effects such as hypokalemia, hemolytic anemia, and so on. Using sustained-release dosage form provides a hopeful solution to this problem. In this study, a gastric floating tablet for sustained-release of Gos (Gos-GFT) was developed using polyvinylpyrrolidone, hydroxypropyl methyl cellulose, ethyl cellulose, lactose, sodium bicarbonate, and magnesium stearate. Gos-GFT had an average weight of around 200 mg with a drug content percentage of around 13.66%. The physicochemical properties of Gos-GFT satisfied the pharmacopoeial requirements for tablets. Gos-GFT was able to float in an acidic medium and had a sustained drug release for over 12 h. In vivo studies showed that the relative bioavailability of Gos-GFT, as compared with Gos powders, was larger than that of a non-gastric floating tablet which was a dosage form used for comparison with Gos-GFT. Furthermore, compared with the Gos powders and the non-gastric floating Gos tablets, Gos-GFT could prolong the in vivo action time of Gos, and significantly relieve hypokalemia which is a major adverse effect of Gos. These properties made Gos-GFT a promising Gos preparation that warrants further investigation for more extensive clinical applications of this natural compound.