Dexamethasone palmitate large porous particles: A controlled release formulation for lung delivery of corticosteroids

Glucocorticoids-based prodrug design: Current strategies and research progress

Attributing to their broad pharmacological effects encompassing anti-inflammation, antitoxin, and immunosuppression, glucocorticoids (GCs) are extensively utilized in the clinic for the treatment of diverse diseases such as lupus erythematosus, nephritis, arthritis, ulcerative colitis, asthma, keratitis, macular edema, and leukemia. However, long-term use often causes undesirable side effects, including metabolic disorders-induced Cushing's syndrome (buffalo back, full moon face, hyperglycemia, etc.), osteoporosis, aggravated infection, psychosis, glaucoma, and cataract. These notorious side effects seriously compromise patients' quality of life, especially in patients with chronic diseases. Therefore, glucocorticoid-based advanced drug delivery systems for reducing adverse effects have received extensive attention. Among them, prodrugs have the advantages of low investment, low risk, and high success rate, making them a promising strategy. In this review, we propose the strategies for the design and summarize current research progress of glucocorticoid-based prodrugs in recent decades, including polymer-based prodrugs, dendrimer-based prodrugs, antibody-drug conjugates, peptide-drug conjugates, carbohydrate-based prodrugs, aliphatic acid-based prodrugs and so on. Besides, we also raise issues that need to be focused on during the development of glucocorticoid-based prodrugs. This review is expected to be helpful for the research and development of novel GCs and prodrugs.

Engineering Inhalable Therapeutic Particles: Conventional and Emerging Approaches

Respirable particles are integral to effective inhalable therapeutic ingredient delivery, demanding precise engineering for optimal lung deposition and therapeutic efficacy. This review describes different physicochemical properties and their role in determining the aerodynamic performance and therapeutic efficacy of dry powder formulations. Furthermore, advances in top-down and bottom-up techniques in particle preparation, highlighting their roles in tailoring particle properties and optimizing therapeutic outcomes, are also presented. Practices adopted for particle engineering during the past 100 years indicate a significant transition in research and commercial interest in the strategies used, with several innovative concepts coming into play in the past decade. Accordingly, this article highlights futuristic particle engineering approaches such as electrospraying, inkjet printing, thin film freeze drying, and supercritical processes, including their prospects and associated challenges. With such technologies, it is possible to reshape inhaled therapeutic ingredient delivery, optimizing therapeutic benefits and improving the quality of life for patients with respiratory diseases and beyond.

Adjunctive dexamethasone palmitate use for intercostal nerve block after video-assisted thoracoscopic surgery: A prospective, randomized control trial

Objectives

The efficacy of dexamethasone palmitate in extending durations of local anesthetic blocks is uncertain. In a randomized, double-blind study of patients undergoing video-assisted thoracoscopic surgery, we tested whether intravenous or perineural dexamethasone palmitate caused prolonged analgesia after intercostal nerve block.

Methods

A total of 90 patients subjected to video-assisted thoracoscopic surgery between May and December 2022 were randomly assigned to one of three intercostal nerve blocks study arms (n = 30 each), requiring the addition of 0.5% ropivacaine (23 ml) as follows: controls (C group), 2 ml saline; IV-DXP group, 2 ml saline + 2 ml (8 mg) intravenous dexamethasone palmitate; and PN-DXP group, 2 ml (8 mg) perineural dexamethasone palmitate. Time to first postoperative remedial analgesia served as primary outcome measure. Secondary endpoints included postoperative opioid consumption, pain scores by Visual Analog Scale, analgesia satisfaction, and related adverse effects.

Results

Compared with controls or the IV-DXP group, time to first postoperative remedial analgesia was longer and postoperative opioid consumption for rescue analgesia was lower in the PN-DXP group (p < 0.01). Similarly, the Visual Analog Scale scores in patients at 8, 12, 18, and 24 h postoperatively were lower in the PN-DXP group than in controls and the IV-DXP group (p < 0.01). Patient satisfaction was statistically lower in the PN-DXP group, compared with either the control or IV-DXP group (p < 0.05). Clinically, the three groups did not differ significantly in occurrences of adverse effects during the 48-h postoperative monitoring period (p > 0.05).

Conclusions

Perineural dexamethasone palmitate is a promising adjunct to ropivacaine intercostal nerve block by prolonging analgesia with almost no related adverse effects.

Development of Large Hollow Particles for Pulmonary Delivery of Cyclosporine A

The purpose of this study was to prepare large hollow particles (LHPs) by spray drying for pulmonary delivery of cyclosporine A (CsA), using L-Leucine (LEU) and hydroxypropyl methylcellulose (HPMC) as excipients and ammonium bicarbonate (AB) as a porogen. The prepared LHPs were spherical particles composed of both CsA and LEU on the surface and HPMC on the inner layer. The formulation of CsA-LEU-0.8HPMC-AB as typical LHPs showed excellent in vitro aerodynamic performance with a minimum mass median aerodynamic diameter (MMAD) of 1.15 μm. The solubility of CsA-LEU-0.8HPMC-AB was about 5.5-fold higher than that of raw CsA, and the dissolution of CsA-LEU-0.8HPMC-AB suggested that the drug was released within 1 h. The cell viability of the A549 cell line showed that CsA-LEU-0.8HPMC-AB was safe for delivering CsA to the lungs. In addition, inhalation administration of CsA-LEU-0.8HPMC-AB with the Cmax and AUC0-∞ increasing by about 2-fold and 2.8-fold compared with the oral administration of Neoral® could achieve therapeutic drug concentrations with lower systemic exposure and significantly improve the in vivo bioavailability of CsA. From these findings, the LHPs, with the advantage of avoiding alveolar macrophage clearance, could be a viable choice for delivering CsA by inhalation administration relative to oral administration.

Heat-Triggered Release of Dexamethasone from Thermosensitive Liposomes Using Prodrugs or Excipients

Dexamethasone (DXM) is a potent glucocorticoid with an anti-inflammatory and anti-angiogenic activity which is widely clinically used. Systemic side effects limit the long-term use of DXM in patients requiring formulations which deliver and selectively release the drug to the diseased tissues. This in vitro study compares the suitability of DXM and commonly used prodrugs dexamethasone-21-phosphate (DXMP) and dexamethasone-21-palmitate (DP) as well as DXM complexed by 2-hydroxypropyl-γ-cyclodextrin (HP-γ-CD) for the use in thermosensitive liposomes (TSL). DXM showed a poor retention and a low final drug:lipid ratio in a 1,2-dipalmitoyl-sn‑glycero-3-phosphodiglycerol-based TSL (DPPG2-TSL) and a low-temperature sensitive liposome (LTSL). In contrast to DXM, DXMP and DP were stably retained at 37 °C in TSL in serum and could be encapsulated with high drug:lipid ratios in DPPG2-TSL and LTSL. DXMP showed a rapid release at mild hyperthermia (HT) from both TSL in serum, whereas DP remained incorporated in the TSL bilayer. According to release experiments with carboxyfluorescein (CF), HP-γ-CD and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) are suitable vehicles for the loading of DXM into DPPG2-TSL and LTSL. Complexation of DXM with HP-γ-CD increased the aqueous solubility of the drug leading to approx. ten times higher DXM:lipid ratio in DPPG2-TSL and LTSL in comparison to un-complexed DXM. Both DXM and HP-γ-CD showed increased release at HT in comparison to 37 °C in serum. In conclusion, DXMP and DXM complexed by HP-γ-CD represent promising candidates for TSL delivery.

Hyaluronic acid-conjugated liposomes loaded with dexamethasone: a promising approach for the treatment of inflammatory diseases

Dexamethasone is a well-known anti-inflammatory drug readily used to treat many lung diseases. However, its side effects and poor lower airway deposition and retention are significant limitations to its usage. In this work, we developed lipid nanoparticulate platforms loaded with dexamethasone and evaluated their behavior in inflammatory lung models in vitro and in vivo. Dexamethasone-loaded liposomes with an average diameter below 150 nm were obtained using a solvent injection method. Three different formulations were produced with a distinct surface coating (polyethylene glycol, hyaluronic acid, or a mixture of both) as innovative strategies to cross the pulmonary mucus layer and/or target CD44 expressed on alveolar proinflammatory macrophages. Interestingly, while electron paramagnetic spectroscopy showed that surface modifications did not induce any molecular changes in the liposomal membrane, drug loading analysis revealed that adding the hyaluronic acid in the bilayer led to a decrease of dexamethasone loading (from 3.0 to 1.7w/w%). In vitro experiments on LPS-activated macrophages demonstrated that the encapsulation of dexamethasone in liposomes, particularly in HA-bearing ones, improved its anti-inflammatory efficacy compared to the free drug. Subsequently, in vivo data revealed that while intratracheal administration of free dexamethasone led to an important inter-animals variation of efficacy, dexamethasone-loaded liposomes showed an improved consistency within the results. Our data indicate that encapsulating dexamethasone into lipid nanoparticles is a potent strategy to improve its efficacy after lung delivery.

Advancements in the Design and Development of Dry Powder Inhalers and Potential Implications for Generic Development

Dry powder inhalers (DPIs) are drug-device combination products where the complexity of the formulation, its interaction with the device, and input from users play important roles in the drug delivery. As the landscape of DPI products advances with new powder formulations and novel device designs, understanding how these advancements impact performance can aid in developing generics that are therapeutically equivalent to the reference listed drug (RLD) products. This review details the current understanding of the formulation and device related principles driving DPI performance, past and present research efforts to characterize these performance factors, and the implications that advances in formulation and device design may present for evaluating bioequivalence (BE) for generic development.

Engineering of levodopa inhalable microparticles in combination with leucine and dipalmitoylphosphatidylcholine by spray drying technique

The aim of this work was to study the effect of concomitant use of leucine and dipalmitoylphosphatidylcholine, in different ratios, on aerosolization performance of levodopa. Three-component formulations were selected based on a central composite design using percentages of leucine and dipalmitoylphosphatidylcholine as the independent variables. Particle size, surface roughness index, surface phosphorus and fine particle fraction were considered as dependent variables in the model. The spray dried samples were also characterized to determine their particle shape and solid state nature. levodopa was spray dried with 10-40% w/w of the excipients to prepare two- or three-component formulations. A crystalline nature was determined for levodopa in all samples spray dried from water:ethanol (30:70 v/v). Roughness in surface of the processed particles increased with increasing total concentration of the excipients, specially above 25% w/w. Analysis of phosphorus on the surface demonstrated that three-component formulations prepared with combination of 12.5% w/w leucine had the highest amount of dipalmitoylphosphatidylcholine in the surface, regardless of its percentage used in the initial feed. A combination of 12.43% w/w of leucine and 9.80% w/w of dipalmitoylphosphatidylcholine used in formulation exhibited the highest fine particle fraction (72.63%). It can be concluded that spray drying of levodopa with a suitable combination of both excipients leads to production of a three-component formulation of crystalline levodopa, with an aerosolization performance which is significantly higher than two-component formulations composed of the drug with either leucine or dipalmitoylphosphatidylcholine.

Repurpose but also (nano)-reformulate! The potential role of nanomedicine in the battle against SARS-CoV2

The coronavirus disease-19 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has taken the world by surprise. To date, a worldwide approved treatment remains lacking and hence in the context of rapid viral spread and the growing need for rapid action, drug repurposing has emerged as one of the frontline strategies in the battle against SARS-CoV2. Repurposed drugs currently being evaluated against COVID-19 either tackle the replication and spread of SARS-CoV2 or they aim at controlling hyper-inflammation and the rampaged immune response in severe disease. In both cases, the target for such drugs resides in the lungs, at least during the period where treatment could still provide substantial clinical benefit to the patient. Yet, most of these drugs are administered systemically, questioning the percentage of administered drug that actually reaches the lung and as a consequence, the distribution of the remainder of the dose to off target sites. Inhalation therapy should allow higher concentrations of the drug in the lungs and lower concentrations systemically, hence providing a stronger, more localized action, with reduced adverse effects. Therefore, the nano-reformulation of the repurposed drugs for inhalation is a promising approach for targeted drug delivery to lungs. In this review, we critically analyze, what nanomedicine could and ought to do in the battle against SARS-CoV2. We start by a brief description of SARS-CoV2 structure and pathogenicity and move on to discuss the current limitations of repurposed antiviral and immune-modulating drugs that are being clinically investigated against COVID-19. This account focuses on how nanomedicine could address limitations of current therapeutics, enhancing the efficacy, specificity and safety of such drugs. With the appearance of new variants of SARS-CoV2 and the potential implication on the efficacy of vaccines and diagnostics, the presence of an effective therapeutic solution is inevitable and could be potentially achieved via nano-reformulation. The presence of an inhaled nano-platform capable of delivering antiviral or immunomodulatory drugs should be available as part of the repertoire in the fight against current and future outbreaks.

Pulmonary Delivery of Docetaxel and Celecoxib by PLGA Porous Microparticles for Their Synergistic Effects Against Lung Cancer

BACKGROUND

using a combination of chemotherapeutic agents with novel drug delivery platforms to enhance the anticancer efficacy of the drug and minimizing the side effects, is very imperative for lung cancer treatments.

OBJECTIVE

The aim of the present study was to develop, characterize, and optimize porous poly (D, L-lactic-co-glycolic acid) (PLGA) microparticles for simultaneous delivery of docetaxel (DTX) and celecoxib (CXB) through the pulmonary route for lung cancer.

METHODS

Drug-loaded porous microparticles were prepared by an emulsion solvent evaporation method. The impact of various processing and formulation variables including PLGA amount, dichloromethane volume, homogenization speed, polyvinyl alcohol volume and concentration were assessed on entrapment efficiency, mean release time, particle size, mass median aerodynamic diameter, fine particle fraction and geometric standard deviation using a two-level factorial design. An optimized formulation was prepared and evaluated in terms of size and morphology using a scanning electron microscope.

RESULTS

FTIR, DSC, and XRD analysis confirmed drug entrapment and revealed no drug-polymer chemical interaction. Cytotoxicity of DTX along with CXB against A549 cells was significantly enhanced compared to DTX and CXB alone and the combination of DTX and CXB showed the greatest synergistic effect at a 1/500 ratio.

CONCLUSION

In conclusion, the results of the present study suggest that encapsulation of DTX and CXB in porous PLGA microspheres with desirable features are feasible and their pulmonary co-administration would be a promising strategy for the effective and less toxic treatment of various lung cancers.

A Pathway From Porous Particle Technology Toward Tailoring Aerogels for Pulmonary Drug Administration

Pulmonary drug delivery has recognized benefits for both local and systemic treatments. Dry powder inhalers (DPIs) are convenient, portable and environmentally friendly devices, becoming an optimal choice for patients. The tailoring of novel formulations for DPIs, namely in the form of porous particles, is stimulating in the pharmaceutical research area to improve delivery efficiency. Suitable powder technological approaches are being sought to design such formulations. Namely, aerogel powders are nanostructured porous particles with particularly attractive properties (large surface area, excellent aerodynamic properties and high fluid uptake capacity) for these purposes. In this review, the most recent development on powder technologies used for the processing of particulate porous carriers are described via updated examples and critically discussed. A special focus will be devoted to the most recent advances and uses of aerogel technology to obtain porous particles with advanced performance in pulmonary delivery.

A quantitative approach to predicting lung deposition profiles of pharmaceutical powder aerosols

Dry powder inhalers (DPI) are widely used systems for pulmonary delivery of therapeutics. The inhalation performance of DPIs is influenced by formulation features, inhaler device and inhalation pattern. The current review presents the affecting factors with great focus on powder characteristics which include particle size, shape, surface, density, hygroscopicity and crystallinity. The properties of a formulation are greatly influenced by a number of physicochemical factors of drug and added excipients. Since available particle engineering techniques result in particles with a set of modifications, it is difficult to distinguish the effect of an individual feature on powder deposition behavior. This necessitates developing a predictive model capable of describing all influential factors on dry powder inhaler delivery. Therefore, in the current study, a model was constructed to correlate the inhaler device properties, inhalation flow rate, particle characteristics and drug/excipient physicochemical properties with the resultant fine particle fraction. The r² value of established correlation was 0.74 indicating 86% variability in FPF values is explained by the model with the mean absolute errors of 0.22 for the predicted values. The authors believe that this model is capable of predicting the lung deposition pattern of a formulation with an acceptable precision when the type of inhaler device, inhalation flow rate, physicochemical behavior of active and inactive ingredients and the particle characteristics of DPI formulations are considered.

Development, In Vitro Characterization, and In Vivo Toxicity Evaluation of Chitosan-Alginate Nanoporous Carriers Loaded with Cisplatin for Lung Cancer Treatment

Polysaccharide-based aerogels are promising drug carriers. Being nanoporous with a high specific surface area allows their use as a drug vehicle for various delivery routes. Intratracheal and intravenous administration of free cisplatin causes toxicity in the rat liver, lungs, and kidneys. In this work, microspherical particles based on alginate-chitosan without a traditional crosslinker were evaluated for targeted delivery of cisplatin by intratracheal administration. The aerogel particles were prepared using the emulsion gelation method, followed by supercritical carbon dioxide extraction. Loading of cisplatin on the prepared porous particles was performed by impregnation using supercritical fluid technology. The prepared carrier and the loaded drug were evaluated for drug content, release, and in vivo acute and subacute toxicity. Cisplatin was successfully loaded (percent drug loading > 76%) on the prepared carrier (particle size = 0.433 ± 0.091 μm) without chemically interacting with the carrier and without losing its crystal form. Sixty percent of cisplatin was released within 2 h, and the rest was loaded inside the polymer pores and had a sustained first-order release over 6 h. Loading cisplatin on the carrier developed herein reduced the cisplatin lung toxicity but increased the liver toxicity after intratracheal administration with nephrotoxicity being proportional to cisplatin dose in case of carrier-loaded cisplatin. Moreover, loading cisplatin on the carrier significantly reduced mortality rate and prevented weight loss in rats as compared to free cisplatin in subacute studies after intratracheal administration. Thus, the developed carrier showed high potential for targeted delivery of cisplatin for lung cancer treatment by inhalation. Graphical abstract.

Development Of Novel Liposome-Encapsulated Combretastatin A4 Acylated Derivatives: Prodrug Approach For Improving Antitumor Efficacy

Purpose

The objective of the present study was to develop a liposomal drug delivery system based on combretastatin A4 (CA4) prodrugs modified with varying alkyl chains and investigate the in vitro drug conversion from prodrug and in vivo antitumor effect.

Methods

The prodrug of CA4 was synthesized with stearyl chloride (18-carbon chain), palmitoyl chloride (16-carbon chain), myristoyl chloride (14-carbon chain), decanoyl chloride (10-carbon chain), and hexanoyl chloride (6-carbon chain) at the 3′-position of the CA4. Subsequently, it was encapsulated with liposomes through the thin-film evaporation method. Furthermore, the characteristics of prodrug-liposome were evaluated using in vitro drug release, conversion, and cytotoxicity assays, as well as in vivo pharmacokinetic, antitumor, and biodistribution studies.

Results

The liposome system with loaded CA4 derivatives was successfully developed with nano-size and electronegative particles. The rate of in vitro drug release and conversion was reduced as the fatty acid carbon chain lengthened. On the contrary, in vivo antitumor effects were improved with the enlargement of the fatty acid carbon chain. The results of the in vivo pharmacokinetic and tissue distribution studies indicated that the reduced rate of CA4 release with a long carbon chain could prolong the circulation time and increase the drug concentration in the tumor tissue.

Conclusion

These results suggested that the release or hydrolysis of the parent drug from the prodrug was closely related with the in vitro and in vivo properties. The slow drug release of CA4 modified with longer acyl chain could prolong the circulation time and increase the concentration of the drug in the tumor tissue. These effects play a critical role in increasing the antitumor efficacy.