Characterization of biologically active insulin-loaded alginate microparticles prepared by spray drying

A review of recent research and development on GLP-1 receptor agonists-sustained-release microspheres

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used in treating type 2 diabetes (T2D). However, owing to their limited oral bioavailability, most commercially available GLP-1 RAs are administered through frequent subcutaneous injections, which may result in poor patient compliance during clinical treatment. To improve patients' compliance, sustained-release GLP-1 RA-loaded microspheres have been explored. This review is an overview of recent progress and research in GLP-1 RA-loaded microspheres. First, the fabrication methods of GLP-1 RA-loaded microspheres including the coacervation method, emulsion-solvent evaporation method based on agitation, premix membrane emulsification technology, spray drying, microfluidic droplet technology, and supercritical fluid technology are summarized. Next, the strategies for maintaining GLP-1 RAs' stability and activity in microspheres by adding additives and PEGylation are reviewed. Finally, the effect of particle size, drug distribution, the internal structure of microspheres, and the hydrogel/microsphere composite strategy on improved release behavior is summarized.

Enhanced powder dispersion of dual-excipient spray-dried powder formulations of a monoclonal antibody and its fragment for local treatment of severe asthma

The advent of biologics has brought renewed hope for patients with severe asthma, a condition notorious for being hampered by poor response to conventional therapies and adverse drug reactions owing to corticosteroid dependence. However, biologics are administered as injections, thereby precluding the benefits inhalation therapy could offer such as increased bioavailability at the site of action, minimal systemic side effects, non-invasiveness, and self-administration. Here, 2-hydroxypropyl-beta-cyclodextrin and ʟ-leucine were co-spray-dried, as protein stabiliser and dispersion enhancer, respectively, at various weight ratios to produce a series of formulation platforms. Powder aerosolisation characteristics and particle morphology were assessed for suitability for pulmonary delivery. The selected platform with the best aerosol performance, a 1:1 ratio of the excipients, was then incorporated with a monoclonal antibody directed against IL-4 receptor alpha or its antigen-binding fragment. The dual-excipient antibody formulations exhibited emitted fraction of at least 80% and fine particle fraction exceeding 60% in cascade impactor study, while the residual moisture content was within a desirable range between 1% and 3%. The in vitro antigen-binding ability and inhibitory potency of the spray-dried antibody were satisfactorily preserved. The results from this study corroborate the viability of inhaled solid-state biomacromolecules as a promising treatment approach for asthma.

Contemporary Aspects of Designing Marine Polysaccharide Microparticles as Drug Carriers for Biomedical Application

The main goal of modern pharmaceutical technology is to create new drug formulations that are safer and more effective. These formulations should allow targeted drug delivery, improved drug stability and bioavailability, fewer side effects, and reduced drug toxicity. One successful approach for achieving these objectives is using polymer microcarriers for drug delivery. They are effective for treating various diseases through different administration routes. When creating pharmaceutical systems, choosing the right drug carrier is crucial. Biomaterials have become increasingly popular over the past few decades due to their lack of toxicity, renewable sources, and affordability. Marine polysaccharides, in particular, have been widely used as substitutes for synthetic polymers in drug carrier applications. Their inherent properties, such as biodegradability and biocompatibility, make marine polysaccharide-based microcarriers a prospective platform for developing drug delivery systems. This review paper explores the principles of microparticle design using marine polysaccharides as drug carriers. By reviewing the current literature, the paper highlights the challenges of formulating polymer microparticles, and proposes various technological solutions. It also outlines future perspectives for developing marine polysaccharides as drug microcarriers.

Customizable Resveratrol Spray-dried Micro-composites for Inhalation as a Promising Contender for Treatment of Idiopathic Pulmonary Fibrosis

The past decades have witnessed tremendous expansion in utilization of plant-derived medicines as resveratrol (RES) in treating several diseases like idiopathic pulmonary fibrosis (IPF). RES can exhibit its role in treating IPF via its outstanding antioxidant and anti-inflammatory activities. The goal of this work was to formulate RES-loaded spray-dried composite microparticles (SDCMs) suitable for pulmonary delivery via dry powder inhaler (DPI). They were prepared by spray drying of a previously prepared RES-loaded bovine serum albumin nanoparticles (BSA NPs) dispersion using different carriers. RES-loaded BSA NPs, prepared by the desolvation technique, acquired suitable particle size of 177.67±0.95 nm and entrapment efficiency of 98.7±0.35% with perfectly uniform size distribution and high stability. Considering the attributes of the pulmonary route, NPs were co-spray dried with compatible carriers viz. mannitol, dextran, trehalose, leucine, glycine, aspartic acid, and glutamic acid to fabricate SDCMs. All formulations showed suitable mass median aerodynamic diameter less than 5 µm; that is suitable for deep lung deposition. However, the best aerosolization behavior was attained from using leucine with fine particle fraction (FPF) of 75.74%, followed by glycine with FPF of 54.7%. Finally, a pharmacodynamic study was conducted on bleomycin-induced mice, and it strongly revealed the role of the optimized formulations in alleviating PF through suppressing the levels of hydroxyproline, tumor necrosis factor-α and matrix metalloproteinase-9 with obvious improvements in the treated lung histopathology. These findings indicate that in addition to leucine, the glycine amino acid, which is not commonly used yet, is very promising in the formulation of DPIs.

Development of multiparticulate systems based on natural polymers for morin controlled release

This study aimed to develop a multiparticulate system based on sodium alginate/gellan gum polymers for morin controlled release using standardized spray-dryer parameters. A 2⁴ experimental factorial design was used to standardize spray-dryer parameters. After standardization, three systems with three different proportions of the natural polymers (50:50, 25:75, 75:25; sodium alginate: gellan gum) with and without morin (control) were developed. The systems were characterized according to its morphology and physicochemical properties. Next, the systems were evaluated regarding antibiofilm and antimicrobial activity against Streptococcus mutans. The factorial design indicated the use of the following parameters: i) air flow rate: 1.0 m³ /min; ii) outlet temperature: 120 °C; iii) natural polymers combination in different proportions; iiii) polymer concentration: 2 %. Scanning electron microscopy showed microparticles with spherical shape and rough surface. The samples released 99.86 % ± 9.36; 85.45 % ± 8.31; 86.87 % ± 3.83 of morin after 480 min. The systems containing morin significantly reduced S. mutans biofilm biomass, microbial viability and acidogenicity when compared to their respective controls. In conclusion, the spray-dryer parameters were standardized to the highest possible yield values and proved to be efficient for morin encapsulation and controlled release. Furthermore, these systems controlled important virulence factors of S. mutans biofilms.

Alginates Combined with Natural Polymers as Valuable Drug Delivery Platforms

Alginates (ALG) have been used in biomedical and pharmaceutical technologies for decades. ALG are natural polymers occurring in brown algae and feature multiple advantages, including biocompatibility, low toxicity and mucoadhesiveness. Moreover, ALG demonstrate biological activities per se, including anti-hyperlipidemic, antimicrobial, anti-reflux, immunomodulatory or anti-inflammatory activities. ALG are characterized by gelling ability, one of the most frequently utilized properties in the drug form design. ALG have numerous applications in pharmaceutical technology that include micro- and nanoparticles, tablets, mucoadhesive dosage forms, wound dressings and films. However, there are some shortcomings, which impede the development of modified-release dosage forms or formulations with adequate mechanical strength based on pure ALG. Other natural polymers combined with ALG create great potential as drug carriers, improving limitations of ALG matrices. Therefore, in this paper, ALG blends with pectins, chitosan, gelatin, and carrageenans were critically reviewed.

Sodium Alginate—Natural Microencapsulation Material of Polymeric Microparticles

From the multitude of materials currently available on the market that can be used in the development of microparticles, sodium alginate has become one of the most studied natural anionic polymers that can be included in controlled-release pharmaceutical systems alongside other polymers due to its low cost, low toxicity, biocompatibility, biodegradability and gelatinous die-forming capacity in the presence of Ca²⁺ ions. In this review, we have shown that through coacervation, the particulate systems for the dispensing of drugs consisting of natural polymers are nontoxic, allowing the repeated administration of medicinal substances and the protection of better the medicinal substances from degradation, which can increase the capture capacity of the drug and extend its release from the pharmaceutical form.

Encapsulation of Bromelain in Combined Sodium Alginate and Amino Acid Carriers: Experimental Design of Simplex-Centroid Mixtures for Digestibility Evaluation

Bromelain has potential as an analgesic, an anti-inflammatory, and in cancer treatments. Despite its therapeutic effects, this protein undergoes denaturation when administered orally. Microencapsulation processes have shown potential in protein protection and as controlled release systems. Thus, this paper aimed to develop encapsulating systems using sodium alginate as a carrier material and positively charged amino acids as stabilizing agents for the controlled release of bromelain in in vitro tests. The systems were produced from the experimental design of centroid simplex mixtures. Characterizations were performed by FTIR showing that bromelain was encapsulated in all systems. XRD analyses showed that the systems are semi-crystalline solids and through SEM analysis the morphology of the formed systems followed a pattern of rough microparticles. The application of statistical analysis showed that the systems presented behavior that can be evaluated by quadratic and special cubic models, with a p-value < 0.05. The interaction between amino acids and bromelain/alginate was evaluated, and free bromelain showed a reduction of 74.0% in protein content and 23.6% in enzymatic activity at the end of gastric digestion. Furthermore, a reduction of 91.6% of protein content and 65.9% of enzymatic activity was observed at the end of intestinal digestion. The Lis system showed better interaction due to the increased stability of bromelain in terms of the amount of proteins (above 63% until the end of the intestinal phase) and the enzymatic activity of 89.3%. Thus, this study proposes the development of pH-controlled release systems aiming at increasing the stability and bioavailability of bromelain in intestinal systems.

Preparation and Characteristics of Alginate Microparticles for Food, Pharmaceutical and Cosmetic Applications

Alginates are the most widely used natural polymers in the pharmaceutical, food and cosmetic industries. Usually, they are applied as a thickening, gel-forming and stabilizing agent. Moreover, the alginate-based formulations such as matrices, membranes, nanospheres or microcapsules are often used as delivery systems. Alginate microparticles (AMP) are biocompatible, biodegradable and nontoxic carriers, applied to encapsulate hydrophilic active substances, including probiotics. Here, we report the methods most frequently used for AMP production and encapsulation of different actives. The technological parameters important in the process of AMP preparation, such as alginate concentration, the type and concentration of other reagents (cross-linking agents, oils, emulsifiers and pH regulators), agitation speed or cross-linking time, are reviewed. Furthermore, the advantages and disadvantages of alginate microparticles as delivery systems are discussed, and an overview of the active ingredients enclosed in the alginate carriers are presented.

Spray-Dried and Spray-Freeze-Dried Powder Formulations of an Anti-Interleukin-4Rα Antibody for Pulmonary Delivery

OBJECTIVE

The therapeutic options for severe asthma are limited, and the biological therapies are all parenterally administered. The purpose of this study was to formulate a monoclonal antibody that targets the receptor for IL-4, an interleukin implicated in the pathogenesis of severe asthma, into a dry powder intended for delivery via inhalation.

METHODS

Dehydration was achieved using either spray drying or spray freeze drying, which exposes the thermolabile biomacromolecules to stresses such as shear and adverse temperatures. 2-hydroxypropyl-beta-cyclodextrin was incorporated into the formulation as protein stabiliser and aerosol performance enhancer. The powder formulations were characterised in terms of physical and aerodynamic properties, while the antibody was assessed with regard to its structural stability, antigen-binding ability, and in vitro biological activity after drying.

RESULTS

The spray-freeze-dried formulations exhibited satisfactory aerosol performance, with emitted fraction exceeding 80% and fine particle fraction of around 50%. The aerosolisation of the spray-dried powders was hindered possibly by high residual moisture. Nevertheless, the antigen-binding ability and inhibitory potency were unaffected for the antibody in the selected spray-dried and spray-freeze-dried formulations, and the antibody was physically stable even after one-year storage at ambient conditions.

CONCLUSIONS

The findings of this study establish the feasibility of developing an inhaled dry powder formulation of an anti-IL-4R antibody using spray drying and spray freeze drying techniques with potential for the treatment of severe asthma.

Development of drug alone and carrier-based GLP-1 dry powder inhaler formulations

The study aimed to develop two types of dry powder inhaler (DPI) formulations containing glucagon-like peptide-1(7-36) amide (GLP-1): carrier-free (drug alone, no excipients) and carrier-based DPI formulations for pulmonary delivery of GLP-1. This is the first study focusing on the development of excipient free GLP-1 DPI formulations for inhaled therapy in Type 2 diabetes. The aerosolisation performance of both DPI formulations was studied using a next generation impactor and a DPI device (Handihaler®) at flow rate of 30 L min^-1. Carriers employed were either a 10% w/w glycine-mannitol prepared by spray freeze drying or commercial mannitol. Spray freeze dried (SFD) carrier was spherical and porous whereas commercial mannitol carrier exhibited elongated particles (non-porous). GLP-1 powder without excipients for inhalation was prepared using spray drying and characterised for morphology including size, thermal behaviour, and moisture content. Spray dried (SD) GLP-1 powders showed indented/dimpled particles in the particle size range of 1 to 5 µm (also mass median aerodynamic diameter, MMAD: <5 µm) suitable for pulmonary delivery. Across formulations investigated, carrier-free DPI formulation showed the highest fine particle fraction (FPF: 90.73% ± 1.76%, mean ± standard deviation) and the smallest MMAD (1.96 µm ± 0.07 µm), however, low GLP-1 delivered dose (32.88% ± 7.00%, total GLP-1 deposition on throat and all impactor stages). GLP-1 delivered dose was improved by the addition of SFD 10% glycine-mannitol carrier to the DPI formulation (32.88% ± 7.00% -> 45.92% ± 5.84%). The results suggest that engineered carrier-based DPI formulations could be a feasible approach to enhance the delivery efficiency of GLP-1. The feasibility of systemic pulmonary delivery of SD GLP-1 for Type 2 diabetes therapy can be further investigated in animal models.

Polysaccharide Chemistry in Drug Delivery, Endocrinology, and Vaccines

Polysaccharides, due to their outstanding properties, have attracted the attention of researchers, working in the biomedical field and especially of those working in drug delivery. Modified/functionalized polysaccharides further increase the importance for various applications. Delivery of therapeutics for diverse ailments in different endocrine glands and hormones safely, is a focal point of researchers working in the field. Among the routes followed, the transdermal route is preferred due to non-exposure of active moieties to the harsh gastric environment and first-pass metabolism. This review starts with the overview of polysaccharides used for the delivery of various therapeutic agents. Advantages of polysaccharides used in the transdermal route are addressed in detail. Types of polysaccharides will be elaborated through examples, and in this context, special emphasis will be on the polysaccharides being used for synthesis of the membranes/films. Techniques employed for their modification to design novel carriers for therapeutics delivery will also be discussed. The review will end with a brief discussion on recent developments and future perspectives for delivery of therapeutic agents, and vaccine development.

Spray drying as an advantageous strategy for enhancing pharmaceuticals bioavailability

Spray drying is an efficient technique that is used not only for rapid evaporation of the solvent from different systems but also for designing ultra-fine particles with various desirable characteristics. The obtained powders demonstrate reasonably narrow size distribution with a submicron-to-micron size range. It is one of the recent techniques applied to present acceptable solutions to enhance the absorption and bioavailability of some challenging drugs. In view of that, the purpose of this review is to shed some light on the wide variety of the recently developed fine particulate products that can be produced from spray-drying technique. This article reports the most outstanding advantages and challenges that could be overcome by exploiting the spray-drying technique for the production of different pharmaceuticals, including pure drug particles and drug-loaded polymeric carriers. The potential of this technique, whether used alone or in combination with other methods, in order to develop reproducible and scalable procedures for the best translation of bench-to-bedside innovation of pharmaceutical products is hereby discussed.

Development and characterization of benznidazole nano- and microparticles: A new tool for pediatric treatment of Chagas disease?

Benznidazole (BNZ) is the drug of choice for the treatment of Chagas disease in many countries. However, its low water solubility produces low and/or variable oral bioavailability. Thus, the aim of this work was to formulate micro- and nanoparticles based on Eudragit^® RS PO and Eudragit^® RL PO as a convenient approach to increase the dissolution rate of BNZ. The microparticles were obtained by means of spray-drying process while the nanoparticles were prepared through the nanoprecipitation technique and further freeze-drying. The results indicated that nanoparticles were obtained in 86% yield while microparticles were obtained in 68% yield. In both cases, the encapsulation efficiency of particles was greater than 78% while drug loading capacity was nearly 24% w/w and 18% w/w, after spray-drying and freeze-drying procedures, respectively. Images of scanning electron microscopy showed that the particles obtained by spray-drying and freeze-drying were in the micrometer and nanometer scale, respectively. FT-IR spectra of BNZ-loaded particles obtained by both methods showed characteristic bands of BNZ confirming that part of drug remained on their surface. Thermal analysis revealed that the drug crystallinity after both methods decreased. Physical stability evaluation of the nanoparticles confirmed that Pluronic^® F68 was suitable to keep the particles size in a range of 300 nm after 70 days storage at 4 ± 2 °C. In-vitro release studies showed increased dissolution rate of drug from the particles obtained by both methods respect to untreated BNZ. The kinetics of drug release in acid media followed the Higuchi kinetics indicating drug diffusion mechanism from particles.

A collagen cardiac patch incorporating alginate microparticles permits the controlled release of hepatocyte growth factor and insulin-like growth factor-1 to enhance cardiac stem cell migration and proliferation

Cardiac stem cells (CSCs) represent a logical cell type to exploit as a regenerative treatment option for tissue damage accrued as a result of a myocardial infarction. However, the isolation and expansion of CSCs prior to cell transplantation is time consuming, costly and invasive, and the reliability of cell expansion may also prove to be a major obstacle in the clinical application of CSC-based transplantation therapy after a myocardial infarction. In order to overcome this, we propose the incorporation of growth factor-eluting alginate microparticles into collagen-based scaffolds as an implantable biomaterial to promote the recruitment and expansion of CSCs in the myocardium. In order to obtain scaffolds able to enhance the motogenic and proliferative potential of CSCs, the aim of this work was to achieve a sustained delivery of both hepatocyte growth factor and insulin-like growth factor-1. Both proteins were initially encapsulated in alginate microparticles by spray drying and subsequently incorporated into a collagen scaffold. Microparticles were seen to homogeneously distribute through the interconnected scaffold pore structure. The resulting scaffolds were capable of extending the release of both proteins up to 15 days, a three-fold increase over non-encapsulated proteins embedded in the scaffolds. In vitro assays with isolated CSCs demonstrated that the sustained release of both bioactive proteins resulted in an increased motogenic and proliferative effect. As presently practiced, the isolation and expansion of CSCs for autologous cell transplantation is slow, expensive and difficult to attain. Thus, there is a need for strategies to specifically activate in situ the intrinsic cardiac regenerative potential represented by the CSCs using combinations of growth factors obviating the need for cell transplantation. By favouring the natural regenerative capability of CSCs, it is hypothesized that the cardiac patch presented here will result in positive therapeutic outcomes in MI and heart failure patients in the future. Copyright © 2016 John Wiley & Sons, Ltd.

Advantages and challenges of the spray-drying technology for the production of pure drug particles and drug-loaded polymeric carriers

Spray-drying is a rapid, continuous, cost-effective, reproducible and scalable process for the production of dry powders from a fluid material by atomization through an atomizer into a hot drying gas medium, usually air. Often spray-drying is considered only a dehydration process, though it also can be used for the encapsulation of hydrophilic and hydrophobic active compounds within different carriers without substantial thermal degradation, even of heat-sensitive substances due to fast drying (seconds or milliseconds) and relatively short exposure time to heat. The solid particles obtained present relatively narrow size distribution at the submicron-to-micron scale. Generally, the yield% of spray-drying at laboratory scale with conventional spray-dryers is not optimal (20-70%) due to the loss of product in the walls of the drying chamber and the low capacity of the cyclone to separate fine particles (<2 μm). Aiming to overcome this crucial drawback in early development stages, new devices that enable the production of submicron particles with high yield, even for small sample amounts, have been introduced into the market. This review describes the most outstanding advantages and challenges of the spray-drying method for the production of pure drug particles and drug-loaded polymeric particles and discusses the potential of this technique and the more advanced equipment to pave the way toward reproducible and scalable processes that are critical to the bench-to-bedside translation of innovative pharmaceutical products.

Advanced protein formulations

It is well recognized that protein product development is far more challenging than that for small-molecule drugs. The major challenges include inherent sensitivity to different types of stresses during the drug product manufacturing process, high rate of physical and chemical degradation during long-term storage, and enhanced aggregation and/or viscosity at high protein concentrations. In the past decade, many novel formulation concepts and technologies have been or are being developed to address these product development challenges for proteins. These concepts and technologies include use of uncommon/combination of formulation stabilizers, conjugation or fusion with potential stabilizers, site-specific mutagenesis, and preparation of nontraditional types of dosage forms-semiaqueous solutions, nonfreeze-dried solid formulations, suspensions, and other emerging concepts. No one technology appears to be mature, ideal, and/or adequate to address all the challenges. These gaps will likely remain in the foreseeable future and need significant efforts for ultimate resolution.

Novel drug delivery system: an immense hope for diabetics

CONTEXT

Existing medication systems for the treatment of diabetes mellitus (DM) are inconvenient and troublesome for effective and safe delivery of drugs to the specific site. Therefore, investigations are desired to deliver antidiabetics using novel delivery approaches followed by their commercialization.

OBJECTIVE

The present review aims to provide a compilation on the latest development in the field of novel drug delivery systems (NDDSs) for antidiabetics with special emphasis on particulate, vesicular and miscellaneous systems.

METHODS

Review of literature (restricted to English language only) was done using electronic databases like Pubmed® and Scirus, i.e. published during 2005-2013. The CIMS/MIMS India Medical Drug Information eBook was used regarding available marketed formulation of antidiabetic drugs. Keywords used were "nanoparticle", "microparticle", "liposomes", "niosomes", "transdermal systems", "insulin", "antidiabetic drugs" and "novel drug delivery systems". Single inclusion was made for one article. If in vivo study was not done then article was seldom included in the manuscript.

RESULTS

The curiosity to develop NDDSs of antidiabetic drugs with special attention to the nanoparticulate system followed by microparticulate and lipid-based system is found to emerge gradually to overcome the problems associated with the conventional dosage forms and to win the confidence of end users towards the higher acceptability.

CONCLUSION

In the current scientific panorama when the area of novel drug delivery system has been recognized for its palpable benefits, unique potential of providing physical stability, sustained and site-specific drug delivery for a scheduled period of time can open new vistas for precise, safe and quality treatment of DM.