Tranexamic acid loaded gellan gum-based polymeric microbeads for controlled release: In vitro and in vivo assessment

Physicochemical, structural, and in-vitro release properties of carboxymethyl cellulose-based cryogel beads incorporating resveratrol-loaded microparticles for colon-targeted delivery system

The objective of this study was to investigate the physicochemical, structural, and in vitro release properties of carboxymethyl cellulose (CMC)-based cryogel beads incorporating resveratrol-loaded microparticles (MP) for colon-targeted delivery system. CMC-based cryogel beads were produced by ionic cross-linking with different concentrations (2%, 3%, and 4%) of AlCl3. Based on FE-SEM images, CMC-based cryogel beads showed a smoother surface and more compact internal structure with increasing AlCl3 concentrations, which was proven to be due to the new cross-linking between the -COO- group of CMC and Al3+ by FT-IR analysis. The encapsulation efficiency of the cryogel beads was significantly increased from 79.48% to 85.74% by elevating the concentrations of AlCl3 from 2% to 4%, respectively. In vitro release study showed that all CMC-based cryogel beads had higher stability for resveratrol than MP in simulated gastric conditions and can efficiently deliver resveratrol to colon without the premature release.

Prolonged joint cavity retention of tranexamic acid achieved by a solid-in-oil-in-gel system: A preliminary study

Tranexamic acid (TXA) is an anti-fibrinolysis agent widely used in postoperative blood loss management. As a highly water-soluble drug, TXA is suffering from rapid clearance from the action site, therefore, large amount of drug is required when administered either by intravenously or topically. In this study, a TXA preparation with prolonged action site residence was designed using the nano-micro strategy. TXA nanoparticles were dispersed in oil by emulsification followed by lyophilization to give a solid-in-oil suspension, which was used as the oil phase for the preparation of TXA-loaded solid-in-oil-in-water (TXA@S/O/W) system. The particle size of TXA in oil was 207.4 ± 13.50 nm, and the particle size of TXA@S/O/W was 40.5 μm. The emulsion-in-gel system (TXA@S/O/G) was prepared by dispersing TXA@S/O/W in water solution of PLGA-b-PEG-b-PLGA (PPP). And its gelling temperature was determined to be 26.6 ℃ by a rheometer. Sustained drug release was achieved by TXA@S/O/G with 72.85 ± 7.52 % of TXA released at 120 h. Formulation retention at the joint cavity was studied by live imaging, and the fluorescent signals dropped gradually during one week. Drug escape from the injection site via drainage and absorption was investigated by a self-made device and plasma TXA concentration determination, respectively. TXA@S/O/G showed the least drug drainage during test, while more than 70 % of drug was drained in TXA@S/O/W group and TXA solution group. Besides, low yet steady plasma TXA concentration (less than 400 ng/mL) was found after injecting TXA@S/O/G into rat knees at a dosage of 2.5 mg/kg, which was much lower than those of TXA dissolved in PPP gel or TXA solution. In conclusion, sustained drug release as well as prolonged action site retention were simultaneously achieved by the designed TXA@S/O/G system. More importantly, due to the steady plasma concentration, this strategy could be further applied to other highly water-soluble drugs with needs on sustained plasma exposure.

Long-Acting Formulations: A Promising Approach for the Treatment of Chronic Diseases

Medication and patient adherence are the two main aspects of any successful treatment of chronic disease. Even though diseases and its treatment existed for several hundred years, the treatment optimization for a given patient is still a researcher question for scientists. There are differences in treatment duration, prognostic signs and symptoms between patient to patient. Hence, designing ideal formulation to suit individual patient is a challenging task. The conventional formulations like oral solids and liquids gives a partial or incomplete treatment because the patient needs to follow the daily pills for a longer time. In such cases, the long-acting formulations will have better patient compliances as drug will be released for a longer duration. Many such approaches are under the clinical investigation. The favorable pharmacokinetic and pharmacodynamic relationships, will be promising option for the treatment of chronic diseases. In this review, we have highlighted the importance of long-acting formulations in the treatment of chronic diseases and the advent of newer formulation technologies.

Biological Role of Gellan Gum in Improving Scaffold Drug Delivery, Cell Adhesion Properties for Tissue Engineering Applications

Over the past few decades, gellan gum (GG) has attracted substantial research interest in several fields including biomedical and clinical applications. The GG has highly versatile properties like easy bio-fabrication, tunable mechanical, cell adhesion, biocompatibility, biodegradability, drug delivery, and is easy to functionalize. These properties have put forth GG as a promising material in tissue engineering and regenerative medicine fields. Nevertheless, GG alone has poor mechanical strength, stability, and a high gelling temperature in physiological conditions. However, GG physiochemical properties can be enhanced by blending them with other polymers like chitosan, agar, sodium alginate, starch, cellulose, pullulan, polyvinyl chloride, xanthan gum, and other nanomaterials, like gold, silver, or composites. In this review article, we discuss the comprehensive overview and different strategies for the preparation of GG based biomaterial, hydrogels, and scaffolds for drug delivery, wound healing, antimicrobial activity, and cell adhesion. In addition, we have given special attention to tissue engineering applications of GG, which can be combined with another natural, synthetic polymers and nanoparticles, and other composites materials. Overall, this review article clearly presents a summary of the recent advances in research studies on GG for different biomedical applications.

Trauma-targeted delivery of tranexamic acid improves hemostasis and survival in rat liver hemorrhage model

BACKGROUND

Trauma-associated hemorrhage and coagulopathy remain leading causes of mortality. Such coagulopathy often leads to a hyperfibrinolytic phenotype where hemostatic clots become unstable because of upregulated tissue plasminogen activator (tPA) activity. Tranexamic acid (TXA), a synthetic inhibitor of tPA, has emerged as a promising drug to mitigate fibrinolysis. TXA is US Food and Drug Administration-approved for treating heavy menstrual and postpartum bleeding, and has shown promise in trauma treatment. However, emerging reports also implicate TXA for off-target systemic coagulopathy, thromboembolic complications, and neuropathy.

OBJECTIVE

We hypothesized that targeted delivery of TXA to traumatic injury site can enable its clot-stabilizing action site-selectively, to improve hemostasis and survival while avoiding off-target effects. To test this, we used liposomes as a model delivery vehicle, decorated their surface with a fibrinogen-mimetic peptide for anchorage to active platelets within trauma-associated clots, and encapsulated TXA within them.

METHODS

The TXA-loaded trauma-targeted nanovesicles (T-tNVs) were evaluated in vitro in rat blood, and then in vivo in a liver trauma model in rats. TXA-loaded control (untargeted) nanovesicles (TNVs), free TXA, or saline were studied as comparison groups.

RESULTS

Our studies show that in vitro, the T-tNVs could resist lysis in tPA-spiked rat blood. In vivo, T-tNVs maintained systemic safety, significantly reduced blood loss and improved survival in the rat liver hemorrhage model. Postmortem evaluation of excised tissue from euthanized rats confirmed systemic safety and trauma-targeted activity of the T-tNVs.

CONCLUSION

Overall, the studies establish the potential of targeted TXA delivery for safe injury site-selective enhancement and stabilization of hemostatic clots to improve survival in trauma.

Design and characteristics of gellan gum beads for modified release of meloxicam

The aim of the presented work was to design, formulate and evaluate the properties of low-acyl gellan macro beads with the potential application as carriers for oral delivery of meloxicam (MLX) in the prophylaxis of colorectal cancer. The beads were obtained by means of ionotropic gelation technique. Calcium chloride (1.0%, 9.0 × 10^-2 M) was used as the cross-linking agent. Nine different polymer, drug and surfactant (Tween^®80) mixtures were used for production of the beads. The quantitative compositions of the mixtures were generated with the application of the Design of Experiments (DoE) modulus from the STATISTICA Software. The prepared formulations revealed 7.2-27.0% of drug loading and 29.2-50.7% drug encapsulation efficiency. It turned out that 0.5% amount of gellan gum in the mixtures was not sufficient to obtain spherical beads. The morphology and surface of the dried beads were analyzed by SEM. Raman spectra confirmed that MLX did not undergo structural changes during production of the beads. The swelling behavior and degradation of the beads were evaluated in three simulated gastrointestinal fluids at different pH (1.2; 4.5; 6.8). The MLX in vitro release studies were conducted on USP apparatus IV, working in the open loop mode. The obtained results showed that MLX release from the dried beads was pH-dependent. The formulations obtained from mixtures containing 1.0 and 1.5% of gellan may be considered as oral dosage forms for MLX, intended to omit the stomach and release the drug in the distal parts of the gastrointestinal tract.

Inhalable tranexamic acid for haemoptysis treatment

PURPOSE

An inhalable dry powder formulation of tranexamic acid (TA) was developed and tested in a novel high-dose Orbital® multi-breath inhaler. The formulation was specifically intended for the treatment of pulmonary haemorrhage and wound healing associated with haemoptysis.

METHODS

Inhalable TA particles were prepared by spray drying and the powder characterised using laser diffraction, electron microscopy, thermal analysis, moisture sorption and X-ray powder diffraction. The aerosol performance was evaluated using cascade impaction and inline laser diffraction and interaction with epithelia cells and wound healing capacity investigated using Calu-3 air interface model.

RESULTS

The spray dried TA particles were crystalline and spherical with a D0.5 of 3.35 μm. The powders were stable and had limited moisture sorption (0.307%w/w at 90%RH). The Orbital device delivered ca. 38 mg powder per 'inhalation' at 60 l · min(-1) across four sequential shots with an overall fine particle fraction (⩽ 6.4 μm) of 59.3 ± 3.5% based on the emitted mass of ca. 150 mg. The TA particles were well tolerated by Calu-3 bronchial epithelia cells across a wide range of doses (from 1 nM to 10nM) and no increase in inflammatory mediators was observed after deposition of the particles (a decrease in IL-1β, IL-8 and INFγ was observed). Time lapse microscopy of a damaged confluent epithelia indicated that wound closure was significantly greater in TA treated cells compared to control.

CONCLUSION

A stable, high performance aerosol of TA has been developed in a multi-breath DPI device that can be used for the treatment of pulmonary lesions and haemoptysis.