Protein-based drugs are precise therapeutic options for various refractory lung diseases, significantly improving patient prognosis and quality of life. In this study, a comparative spray-drying approach was employed to prepare inhalable dry-powder formulations of bovine serum albumin (BSA), a surface-active model protein, using established pharmaceutical excipients, including 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), trehalose (Tre), leucine (Leu), and a Tre-Leu combination. The relative performance of HP-β-CD was systematically benchmarked against Tre, Leu, and dual-excipient systems under identical formulation and processing conditions, with respect to protein protection and aerodynamic properties. After 3 months of storage under accelerated stability condition (40 ± 2 °C and 20 ± 5% relative humidity), the protein monomer content in the HP-β-CD-based formulations was marginally lower than that observed in the Tre- and dual-excipient-containing dry powders but still demonstrated effective protein protection. Moreover, the aerosol performance of HP-β-CD formulations surpassed that of other excipients, indicating its superior potential for pulmonary delivery of protein molecules. Overall, this comparative study highlights the potential of HP-β-CD as an alternative excipient for protein-based aerosol dry-powder formulations.

Proteins and peptides hold immense promises for treating fatal and rare diseases. However, their complex structures and intrinsic instability pose significant challenges in drug development. The spray drying process offers a continuous and rapid method to stabilize these biomacromolecules, converting them from liquid to solid formulations. However, the spray drying process remains trial-and-error based, requiring extensive resources. This study employs machine learning (ML) algorithms to predict key properties of spray-dried protein and peptide powders, including yield, particle size, residual solvent content, solid states properties, and aggregation, with the aim to help accelerate formulation development and optimize process parameters. In total, 321 yield data points, 288 particle size data points, 357 residual solvent content data points, 205 solid states of the dry powder data points, and 305 aggregation data points were collected and described using various molecular descriptors for model building. Seven ML algorithms were tested to identify the best model to predict the key properties. Light Gradient Boosting Machine (LightGBM) exhibited the best performance for regression tasks, particularly for residual solvent content (mean absolute error = 0.841), and logistic regression excelling in predicting solid state characteristics and aggregation. Feature importance analysis identified protein, excipient, processing parameters, and environmental conditions as critical factors influencing various properties of spray-dried proteins/peptides formulation. The generalizability of the models was experimentally validated using alpha-lactalbumin formulations, the mean absolute error (MAE) in the models of yield, particle size, and residual solvent content were 0.755, 1.591, and 14.492 respectively, and the accuracies in predicting solid states of the dry powder and aggregation were 78.0% and 100.0% respectively. This study demonstrates the potential of machine learning to streamline the development of spray-dried protein formulations, providing a material- and time-saving solution as a reference.

Respiratory diseases remain a major global health concern, where pathological mucus accumulation and chronic inflammation severely compromise lung function. RNA therapeutics have emerged as a transformative modality to address underlying molecular pathologies beyond the capabilities of small-molecule drugs. However, effective delivery of RNA therapeutics to the lungs remains hindered by significant challenges. The instability of lipid nanoparticles (LNPs) in liquid formulations compromises their storage and cold-chain transport, while the pathological mucus hypersecretion characteristic of chronic airway diseases impedes nanoparticle penetration and delivery efficacy. Herein, we propose a functional lyoprotectant strategy that bridges formulation stability and biological functionality within a single design. Specifically, N-acetylcysteine (NAC), a clinically used mucolytic, was incorporated into a sucrose-based lyoprotectant matrix as a functional additive, enabling lyophilization while introducing mucus-modulating capability. The lyophilized LNPs preserved physicochemical integrity, maintained siRNA encapsulation, and achieved efficient mucus penetration and gene silencing in vitro and in vivo. In murine models of mucus-hypersecretory lung disease, a single-dose administration achieved enhanced therapeutic outcomes through a sequential and dual-action complementary mechanism, including extracellular NAC-mediated mucolysis and intracellular RNAi-mediated inflammation suppression. This work pioneers the concept of a functional lyoprotectant, offering a generalizable platform for storage-stable and biologically active inhaled RNA therapeutics.

Protein-based nanoparticles hold great promise for bioactive molecule delivery, but conventional fabrication routes are often complex and rely on surfactants or organic solvents. Here, we reported a crosslinker-free strategy to engineer α-lactalbumin (ALA) nanoparticles via Ca²⁺ mediated ionic bridging and electrospraying, enabling efficient encapsulation of acidic fibroblast growth factor (aFGF). These aFGF@ALA nanoparticles were subsequently integrated into electrospun poly(vinyl alcohol) (PVA) nanofiber matrices to construct hybrid dressings (aFGF@ALA NPs/PVA ENMs). The resulting nanostructures combine the structural support of nanofibers with the controlled release capacity of protein nanoparticles, yielding a synergistic platform for therapeutic delivery. In vitro, the hybrid dressings promoted fibroblasts and keratinocytes proliferation and migration with excellent cytocompatibility. In vivo, they accelerated burn wound repair by enhancing re-epithelialization, collagen I/III remodeling, and angiogenesis. This work introduces a facile and generalizable strategy for designing functional protein-based nanoparticles and demonstrates their integration with nanofiber scaffolds as a versatile platform for growth factor delivery and tissue regeneration.

Wound healing is a complex, multi-phase biological process that continues to pose significant challenges in biomedical engineering. As such, the development of innovative therapeutic strategies and sustainable, multifunctional biomaterials capable of accelerating tissue repair remains a top priority. In this study, we present a green, multiprotein nanofiber-based system fabricated via waterborne electrospinning using water as the sole solvent. The nanofibers, composed of α-lactalbumin (ALA) and soy protein isolate (SPI) with up to 90% (w/w) protein content, were formulated with minimal amounts of polyethylene oxide (PEO). Comprehensive analysis of nanofiber morphology, water stability, and mechanical properties revealed that the combination of ALA and SPI provided enhanced structural tunability and performance compared to single-protein systems. In a rat model of third-degree burns, the ALA/SPI/PEO nanofibers significantly improved wound healing outcomes relative to controls, as evidenced by accelerated re-epithelialization, increased collagen deposition, and enhanced angiogenesis; all this being attributable to the synergistic effects of the two protein components. By integrating sustainability, material design and therapeutic efficacy into a single platform, our multiprotein nanofiber system offers a compelling blueprint for the next generation of eco-conscious and clinically translatable biomaterials.

BACKGROUND:Asthma patients exhibit elevated airway mucus secretion. Small interfering RNA (siRNA) targeting the mucin MUC5AC delivered by lipid nanoparticles (LNPs) is promising but limited by low transfection efficiency. Protopanaxadiol (PPD), protopanaxatriol (PPT), and ginsenoside Rh2 (GR2) were chosen because their dammarane skeleton preserves membrane-insertion capacity for endosomal escape, whereas bulkier multi-glycosylated ginsenosides adversely affect LNP size and stability. PURPOSE:In this study, we designed novel inhaled LNPs incorporating ginseng-derived cholesterol analogs to enhance therapeutic efficacy against asthma. METHODS:PPD and PPT were used as membrane components to formulate anti-MUC5AC siRNA-loaded LNPs (designated as DLNPs and TLNPs). Flow cytometry and confocal laser scanning microscopy (CLSM) were employed to evaluate the cellular uptake and lysosomal escape of LNPs. An asthmatic mouse model was established to assess therapeutic effects of DLNPs and TLNPs through pathological section analysis and determination of inflammatory cytokine levels. RESULTS:The data showed that these novel formulations enhanced cellular uptake by airway epithelial cells (AECs) and promoted siRNA escape from lysosomes, thereby improving pulmonary delivery efficiency. TLNPs, in particular, demonstrated superior performance. Furthermore, DLNPs and TLNPs exerted multifaceted anti‑asthmatic effects in vivo, as evidenced by significant suppression of MUC5AC overexpression in AECs, attenuation of inflammatory cell infiltration, and reduction in the secretion of the critical cytokines IL‑4 and IL‑13. CONCLUSION:Overall, our findings indicate that ginseng-derived PPD and PPT effectively enhance siRNA delivery and mitigate asthma symptoms through dual inhibition of MUC5AC overexpression and airway inflammation. These cholesterol analogs represent promising carrier materials for LNP-based pulmonary therapeutics.

Diabetes exhibits several long-term serious health complications, including healing-impaired wounds, which result in substantial clinical challenges, warranting the need to develop efficient wound dressings. Herein, multifunctional in situ hydrogels as diabetic wound dressings were accomplished by concomitant spraying of 3-aminophenyl boronic acid (PBA)- grafted dialdehyde laminarin (LamPBA) and silver nanoparticles-impregnated polyvinyl alcohol (PVA-AgNPs). The hydrogels with and without AgNPs (F2 and F1, respectively) conferred excellent rheological characteristics and acceptable antibacterial activity (up to 80 % reduction in survival) against E. coli and S. aureus. Cellular experiments revealed that the hydrogels obviously promoted the proliferation and migration of HaCaT and NIH/3 T3 cells. In diabetic mice, the hydrogels accomplished ~90 % wound closure by day 9, outperforming controls (65-70 %). Additionally, F1 and F2 considerably increased the CD206/CD86 ratio (46 ± 5 and 62 ± 7, respectively) compared to diabetic (0.6 ± 0.1) and nondiabetic (2 ± 0.2) controls. Moreover, the hydrogels demonstrated remarkably triggered epidermal tissue regeneration, collagen deposition, antioxidant defense and angiogenesis. The hydrogels containing AgNPs portrayed superior wound healing potential over AgNP-free hydrogels. Overall, the in situ hydrogels (LamPBA/PVA-AgNPs, F2) could augment the diabetic wound healing rates in an effective manner and be utilized as promising wound care biomaterials.

[This corrects the article DOI: 10.1016/j.apsb.2021.07.024.].

The intratracheal route enables an enhanced drug accumulation within the lungs together with reduced systemic exposure, making it a promising approach for treating epidermal growth factor receptor (EGFR)-overexpressed non-small cell lung cancer (NSCLC). In this study, dextran-PEG-erlotinib co-polymers (DPE), novel amphiphilic conjugates with outstanding therapeutic activities against EGFR-overexpressed NSCLC and stabilizing effects were synthesized and facilitated self-assembly of redox-sensitive paclitaxel dimers. The obtained nanoassemblies (DPE dimer NPs) exhibited high drug loading efficiency, satisfactory stability and optimal redox responsive paclitaxel release profile comparable with control nanoassemblies (TPGS dimer NPs), where paclitaxel dimers were assembled in the presence of TPGS, a therapeutically inert stabilizer. The DPE dimer NPs evidenced an enhanced cellular uptake efficiency and cytotoxicity in EGFR-overexpressed HCC827 cells as compared to TPGS dimer NPs. These also demonstrated superior tumor penetration ability and inhibition potential in HCC827 3D tumor spheroid. Compared to TPGS dimer NPs and Taxol® intravenous injection, the DPE dimer NPs illustrated an improved anticancer effect with reduced systemic toxicity and excellent biocompatibility after intratracheal administration to the HCC827 metastatic lung cancer mouse model. These results revealed a great potential of DPE as a stabilizer to synergistically improve the therapeutic efficacy of paclitaxel dimers against EGFR-overexpressed NSCLC after intratracheal administration.

Magnesium stearate (MgSt) has been used as a force control agent (FCA) to enhance the aerosol performance of carrier-based dry-powder inhalers (DPIs). MgSt is a mixture of magnesium salts of fatty acids—primarily stearic acid (SA) and palmitic acid (PA)—and the SA:PA ratio can vary depending on the natural source. In addition, different processing routes can yield variation in both chemical and solid form composition of commercial grade MgSt. This study investigated whether variations in fatty acid composition and hydration state (hydrate form) of MgSt affect the aerosol performance of carrier-based DPIs. Samples of MgSt with different SA/PA molar ratios and hydration states were obtained and micronized, then blended with coarse lactose (carrier) and tratinterol hydrochloride (TH), a new long-acting bronchodilator used as a model drug, to prepare DPI formulations (TH-DPIs). After physicochemical characterization, the aerosol performance of the TH-DPI formulations was assessed using a next generation impactor (NGI). NGI results showed that the fine particle fraction (FPF) of TH-DPIs increased with increasing MgSt content, irrespective of fatty acid composition or hydration state. Changes in the SA/PA ratio had little effect on aerosol performance. In contrast, formulations containing trihydrate MgSt generally exhibited higher FPFs than those containing dihydrate or low-hydration MgSt. In conclusion, changes in the hydration state of MgSt exert a greater impact on DPI aerosol performance than variations in its fatty-acid composition.

Amino acids (AAs) have been employed as excipients in spray-dried (SD) protein formulations due to their stabilizing effects and particle engineering abilities. However, the research focusing on the influence of AAs on the tabletability of SD protein powders is still limited. The aim of this study was to investigate the effects of five diverse AAs, arginine hydrochloride (Arg·HCl), leucine (Leu), glycine (Gly), tryptophan (Trp) and sodium aspartate (Asp·Na), on the compaction behavior and stability of SD trypsin/lactose powders. The SD powders were characterized in terms of morphology, bulk powder properties, residual moisture content, and solid-state structure. Subsequently, the resulting powder compacts were characterized with respect to compressibility, compactability, and tabletability. Lastly, the conformational stability and enzymatic activity of trypsin in different SD formulations after compaction were assessed. The results showed that the SD trypsin/lactose/Arg·HCl powder exhibited the poorest tabletability. Moreover, SD trypsin/lactose/Leu powder showed relatively poor tabletability, while SD trypsin/lactose/Trp powder showed a moderate tabletability. On the other hand, SD trypsin/lactose/Gly powder displayed the best compressibility, and the SD trypsin/lactose/Asp·Na tablets exhibited the highest tensile strengths at high compaction pressures. However, an altered conformation and reduced enzymatic activity of trypsin were observed in the SD trypsin/lactose/Asp·Na formulation upon compaction. In conclusion, the addition of five different AAs to the SD trypsin/lactose powder system resulted in distinct compaction behaviors and stabilizing effects, which can be attributed to the intrinsic properties of the original SD particles, such as hygroscopicity, morphology, and potential AAs' surface distribution.

Long-acting injectables (LAIs) present significant advantages over conventional oral formulations, including sustained drug release, reduced dosing frequency, improved patient adherence, and enhanced therapeutic outcomes. Poly (lactic-co-glycolic acid) (PLGA) and polylactic acid (PLA) have emerged as the most widely used polymers for LAIs over the past decades due to their excellent biocompatibility, biodegradability, non-toxicity, non-immunogenicity, and mechanical strength. Among the various manufacturing techniques employed to produce PLGA-based LAIs, spray-drying has gained increasing attention as a fast, one-step process capable of continuous microparticle production with inherent scalability and particle engineering flexibility. Critical physicochemical properties of spray-dried (SD) microparticles, such as size, morphology, drug loading/encapsulation efficiency, and drug release kinetics, can be precisely tuned by optimizing spray-drying process parameters and material attributes. This review summarizes key advances in SD PLGA-based LAIs, beginning with an overview of PLGA as a foundational material for long-acting formulations. We then discuss the fundamental principles of spray-drying and particle formation mechanism, along with different modes of spray-drying PLGA-based LAIs. Next, critical considerations for developing PLGA-based LAIs via spray-drying are examined. Finally, we highlight current challenges and limitations in SD PLGA-based LAIs development, providing insights into future opportunities.

With an immense advancement in the therapeutic technologies, redox-responsive drug delivery systems have been extensively explored preclinically for the treatment of several critical diseases, including cancer. Particularly, considerable attention has been paid for the fabrication of polysaccharide-based prodrug scaffolds, where a variety of redox-responsive functional groups or pendants is employed to chemically conjugate small-molecule drugs with different carbohydrate polymers. The redox-responsive bonds of such scaffolds could be cleavable at the microenvironmental elevated glutathione (GSH) and reactive oxygen species (ROS) concentrations, triggering a rapid molecular conformational change and release of the bioactive cargos at the targeted sites and eventually minimize the systemic toxic effects. The present article provides an insight into the rational design and fabrication of recently developed redox-responsive polysaccharide-based prodrug scaffolds and their improved bio-performances relative to their therapeutic precursors, following a comprehensive overview on microenvironmental dysregulated redox homeostasis and various redox-responsive motifs. The prospects and challenges of these conjugates are also briefly discussed for future development of promising redox-responsive nanomedicines.

Metastatic lung cancer's immunosuppressive tumor microenvironment (TME) remains a significant barrier to effective immunotherapy. While inhaled vaccination offers a promising strategy for local TME remodeling, potent and safe immunostimulants remain lacking. Bacterial outer membrane vesicles (OMVs) are emerging as promising nanoplatforms for cancer immunotherapy; however, their therapeutic efficacy, safety, and underlying mechanisms against metastatic lung cancer via lung mucosal immunity remain largely unexplored. To address this, we developed glycine-induced OMVs (Gomv) as a novel inhaled in situ vaccine, strategically leveraging preparation methodology to influence immunostimulatory function. This methodology-driven engineering significantly boosted immunogenicity, achieving a 7.28-fold increase in production yield alongside a substantially reduced lipopolysaccharide content (0.107 ± 0.002 ng/μg) and an enriched outer membrane protein profile (e.g., OmpA and OmpC) compared to other OMVs. Importantly, our results showed that Gomv targeted alveolar macrophages and promoted tumor phagocytosis and M1 polarization by activating the FPR1/2 and NF-κB pathways. The consequent release of tumor antigens functioned as an effective in situ vaccine, activating cytotoxic T cells and reprogramming the immunosuppressive TME through coordinated cytokine signaling (including IFN-α, IFN-γ, and Granzyme B). Critically, pulmonary delivery of Gomv achieved 83.17 % tumor suppression in metastatic lung cancer models with a favorable safety profile. Our study establishes a glycine-induced engineering strategy for developing efficient and safe inhalable vaccine platforms, providing a reference for bacterial vesicle-based platforms in pulmonary immunotherapy.

Cationic lipids play a pivotal role in developing novel drug delivery systems for diverse biomedical applications, owing to the success of mRNA vaccines against COVID-19 and the Phase III antitumor agent EndoTAG-1. However, the therapeutic potential of these positively charged liposomes is limited by dose-dependent toxicity. While an increased content of cationic lipids in the formulation can enhance the uptake and cytotoxicity toward tumor-associated cells, it is crucial to balance these advantages with the associated toxic side effects. In this work, we synthesized the cationic lipid HC-Y-2 and incorporated it into sialic acid (SA)-modified cationic liposomes loaded with paclitaxel to target tumor-associated immune cells efficiently. The SA-modified cationic liposomes exhibited enhanced binding affinity toward both RAW264.7 cells and 4T1 tumor cells in vitro due to the increased ratios of cationic HC-Y-2 content while effectively inhibiting 4T1 cell lung metastasis in vivo. By leveraging electrostatic forces and ligand-receptor interactions, the SA-modified cationic liposomes specifically target malignant tumor-associated immune cells such as tumor-associated macrophages (TAMs), reduce the proportion of cationic lipids in the formulation, and achieve dual objectives: high cellular uptake and potent antitumor efficacy. These findings highlight the potential advantages of this innovative approach utilizing cationic liposomes.

Idiopathic pulmonary fibrosis (IPF) is a progressive pulmonary disease that leads to interstitial inflammation, lung damage, and eventually life-threatening complications. Among various pathologic factors, Smad4 is a pivotal molecule involved in the progression and exacerbation of IPF. It mediates nuclear transfer of Smad2/Smad3 complexes and initiates the transcription of fibrosis-promoting genes. Thus, the inhibition of Smad4 expression in pulmonary fibroblasts by small interfering RNAs (siRNAs) might be a promising therapeutic strategy for IPF. Herein, we engineered exosome membranes (EM) by cationic lipid (i.e., DOTAP) to load siRNAs against Smad4 (DOTAP/siSmad4@EM), and investigated their specific delivery to pulmonary fibroblasts for treating IPF in a mouse model via pulmonary administration. As reference nanoscaffolds, undecorated DOTAP/siSmad4 complexes (lipoplexes, consisting of cationic lipid DOTAP and siRNAs) and siSmad4-loaded lipid nanoparticles (DOTAP/siSmad4@lipo, consisting of lipoplexes fused with DPPC-Chol liposomes) were also prepared. The results showed that DOTAP/siSmad4@EM exhibited a higher cellular uptake and gene silencing efficacies in mouse pulmonary fibroblasts (viz., MLg2908) as compared to the two reference nanoscaffolds. Furthermore, the outcomes of the in vivo experiments illustrated that DOTAP/siSmad4@EM could significantly down-regulate the Smad4 expression with augmented anti-fibrosis efficiency. Additionally, the DOTAP/siSmad4@EM conferred excellent biocompatibility with low cytokine levels in bronchoalveolar lavage fluid and proinflammatory responses in the pulmonary area. Taken together, the outcomes of our investigation imply that specific inhibition of Smad4 expression in pulmonary fibroblasts by pulmonary administrated DOTAP/siSmad4@EM is a promising therapeutic strategy for IPF, which could safely and effectively deliver siRNA drugs to the targeted site of action.

Inhaled medicines continue to be an essential part of treatment for respiratory diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. In addition, inhalation technology, which is an active area of research and innovation to deliver medications via the lung to the bloodstream, offers potential advantages such as rapid onset of action, enhanced bioavailability, and reduced side effects for local treatments. Certain inhaled macromolecules and particles can also end up in different organs via lymphatic transport from the respiratory epithelium. While the majority of research on inhaled medicines is focused on the delivery technology, particle engineering, combination therapies, innovations in inhaler devices, and digital health technologies, researchers are also exploring new pharmaceutical technologies and strategies to prolong the duration of action of inhaled drugs. This is because, in contrast to most inhaled medicines that exert a rapid onset and short duration of action, long-acting inhaled medicines (LAIM) improve not only the patient compliance by reducing the dosing frequency, but also the effectiveness and convenience of inhaled therapies to better manage patients' conditions. This paper reviews the advances in LAIM, the pharmaceutical technologies and strategies for developing LAIM, and emerging new inhaled modalities that possess a long-acting nature and potential in the treatment and prevention of various diseases. The challenges in the development of the future LAIM are also discussed where active research and innovations are taking place.

Amino acids (AAs) have been used as excipients in protein formulations both in solid and liquid state products due to their stabilizing effect. However, the mechanisms by which they can stabilize a protein have not been fully elucidated yet. The purpose of this study was to investigate the effect of AAs with distinct physicochemical properties on the stability of a model protein (lysozyme, LZM) during the spray -drying process and subsequent storage. Molecular descriptor based multivariate data analysis was used to select distinct AAs from the group of 20 natural AAs. Then, LZM and the five selected AAs (1:1 wt ratio) were spray-dried (SD). The solid form, residual moisture content (RMC), hygroscopicity, morphology, secondary/tertiary structure and enzymatic activity of LZM were evaluated before and after storage under 40 degrees C/75 % RH for 30 days. Arginine (Arg), leucine (Leu), glycine (Gly), tryptophan (Trp), aspartic acid (Asp) were selected because of their distinct properties by using principal component analysis (PCA). The SD LZM powders containing Arg, Trp, or Asp were amorphous, while SD LZM powders containing Leu or Gly were crystalline. Recrystallization of Arg, Trp, Asp and polymorph transition of Gly were observed after the storage under accelerated conditions. The morphologies of the SD particles vary upon the different AAs formulated with LZM, implying different drying kinetics of the five model systems. A tertiary structural change of LZM was observed in the SD powder containing Arg, while a decrease in the enzymatic activity of LZM was observed in the powders containing Arg or Asp after the storage. This can be attributed to the extremely basic and acidic conditions that Arg and Asp create, respectively. This study suggests that when AAs are used as stabilizers instead of traditional disaccharides, not only do classic vitrification theory and water replacement theory play a role, but the microenvironmental pH conditions created by basic or acidic AAs in the starting solution or during the storage of solid matter are also crucial for the stability of SD protein products.

Development of oral solid dosage forms containing biologics has attracted intense interests recently due to the high patient convenience and the commercial potential of related products. The aim of this study was to understand how the difference in the particle properties prepared using two different drying principles, i.e. freezedrying and spray-drying, may influence the compaction behavior of particulate protein systems. Here, trypsin was used as a model protein drug and lactose as a filler. The raw freeze-dried (FD) powder composed mostly of trypsin and lactose was dissolved in Milli-Q water and processed by spray-drying to produce spray-dried (SD) powder. Meanwhile, the raw FD powder was micronized by a ball mill into fine ball-milled (BM) powder with a comparable particle size to that of SD powder. Next, the FD, BM and SD powders were characterized with regard to morphology, residual moisture content (RMC), solid form, and surface chemistry using scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), and X-ray photoelectron spectroscopy (XPS), respectively. Subsequently, a compaction simulator was employed to prepare tablets within the compaction pressure range of 25 to 400 MPa. The results showed that FD and BM powders could be compressed into tablets within the investigated compaction pressure range. In contrast, tablets compacted from SD powder displayed capping/lamination tendency under high compaction pressures and thus had poor tabletability. XPS analyses revealed that there were more surface enrichments of trypsin in the SD powder compared to that of FD powder. It implies that there would be more hydrophobic inter-particulate trypsin-trypsin interactions and less hydrophilic lactose-lactose interactions during the compression of SD powder compared to the compaction of FD powder. The weak hydrophobic inter-particulate trypsin-trypsin interactions may not be maintained during the decompression phase especially when compacted at high compaction pressure ranges, resulting in capping/lamination of the SD tablets. This study demonstrates that the two drying principles, i.e. freeze-drying and spray-drying, can result in different particle properties of biologics, which can in turn influence the tabletability of the resulting solid materials.