Recent Advances in Freeze-Drying: Variables, Cycle Optimization, and Innovative Techniques

Mini Review on the Lyophilization: A Basic Requirement for Formulation Development and Stability Modifier

Freeze-drying is popular for producing pharmaceutical formulations with structurally complicated active components and drug delivery system carriers. It is the process of eliminating water from ice crystals through the sublimation mechanism. Some formulations may require drug-specific excipients such as stabilizers, buffers, and bulking agents to maintain the appearance and assure the long-term stability of the drug product. This approach is utilized for therapeutic compounds that are moisture sensitive, thermolabile, and degrade in the atmosphere. Freezing and primary and secondary drying are critical processes in the lyophilization process because they directly impact the end result. This approach is effective for producing a variety of dosage forms, including oral, inhalation, and parenteral. As a result, lyophilization may be an important method for improving the therapeutic efficacy and delivery of various dosage forms delivered via different routes. Additionally, lyophilization is used in pharmacological research to preserve biological samples, stabilize reference/standards, and increase the solubility and bioavailability of poorly soluble drugs. Thus, lyophilization is critical for maintaining the stability, efficacy, and safety of pharmaceutical products throughout their development and lifecycles. This article includes a broad overview of the lyophilization process, principle, excipients for lyophilized medicine compositions, and new lyophilization technologies as well as their applications in a variety of fields.

Effect of low-frequency assisted ultrasonic on cryopreservation of L-02 hepatocyte cells

Developing bioartificial liver and hepatocyte transplantation technology causes increasing hepatocyte cell demand. Effective long-term hepatocyte cell preservation methods are necessary to promote. Progressive cooling is a key preservation technology for cell banks. However, the cell solution needs to be supercooled in a slow freezing process. The high degree of supercooling possibly induces uncontrollable intracellular ice formation. This work designs an ultrasonic ice-seeding system for L-02 hepatocyte cell preservation, reducing supercooling and improving cell survival rate. The effect of ultrasonic intensities on the hepatocyte's survival rate was investigated and optimized. The results prove the calorimetric method can efficiently measure the ultrasonic intensity dissipated in the hepatocyte cell preservation solution. When the ultrasonic intensity is 0.0329 W/cm2 ∼ 0.4316 W/cm2, the hepatocyte survival rate is over 90%. There is no significant difference between experiment groups (p < 0.05) when the ultrasonic intensity is larger than 0.4316 W/cm2. The hepatocyte cell survival rate reduced significantly with the increase of ultrasonic intensity. The 7-day hepatic function indicator experiment results indicate that the ultrasonic ice seeding has the weakest impact on hepatocyte cells in the four groups. The secretion of urea, albumin and glucose proved that ultrasonic ice seeding technology does not affect cell secretion and has an enormous advantage in cryopreservation. It can be widely applied to cell freezing fields.

Research progress in the application of infrared blanching in fruit and vegetable drying process

Fruits and vegetables offer substantial nutritional and health benefits, but their short shelf life necessitates effective preservation methods. Conventional drying techniques, while efficient, often lead to deterioration in food quality. Recent advancements highlight the potential of infrared blanching (IRB) as a preparatory process to improve drying outcomes. This review systematically evaluated the application of IRB for various fruits and vegetables, including tomatoes, potatoes, carrots, mangoes, apples, peaches, strawberries, grapes, and green beans. IRB demonstrated notable improvements in texture, color retention, and nutrient preservation in dried products. Key operational parameters for effective IRB include product thickness (2-5 cm), treatment duration (30 s to several minutes), and the distance from the infrared (IR) emitter (10-30 cm). These factors collectively ensure efficient heat penetration and energy transfer. Regarding IR generators, far-IR heaters are advantageous due to their uniform heating capabilities, whereas near-IR heaters deliver rapid heating. Catalytic IR generators are also emerging as promising options for industrial-scale applications. This review further explores the principles and mechanisms of IRB, particularly its impact on drying kinetics and the retention of vitamins, antioxidants, and bioactive compounds. Evidence indicates that IRB can reduce drying times by up to 50%, increase drying rates, and lower energy consumption by approximately 17%, achieving energy efficiency levels of 80%-90%. However, limitations such as the shallow penetration depth of IR radiation remain challenging. Potential solutions, such as the development of hybrid blanching methods, are discussed to optimize the drying process further and enhance the quality of dried fruits and vegetables.

Practical advice in the development of a lyophilized protein drug product

The development of lyophilized protein drug products is a critical and complex task in the pharmaceutical industry, requiring a comprehensive understanding of the myriad of factors affecting product quality, stability, and the efficiency and robustness of the lyophilization process. This review offers practical advice on the critical aspects of lyophilized protein drug product development. Practical considerations across both the early and late stages of development are discussed, underscoring the necessity of a strategic approach from initial development through to commercialization. The review then delves into formulation optimization strategies that are essential for enhancing protein stability and the efficiency of the lyophilization process. This section outlines stable formulation design and highlights the unique considerations required for high protein concentration lyophilized drug products. It further explores the formulation strategies to enhance the lyophilization process' efficiency. Moreover, the paper examines the critical elements in selecting primary containers and closures for lyophilized drug products, focusing on vials and dual chamber systems. The analysis encompasses the effects of the container/closure's material, size, geometry, and fill volume on product quality and process efficiency. Lastly, the review provides practical considerations in lyophilization cycle development, including the design and optimization of the freezing, primary drying, and secondary drying stages to achieve a robust, scalable, and efficient lyophilization process. By offering comprehensive insights into these key areas to enhance their understanding and implementation of best practices in the field, this paper serves as a useful resource for researchers, formulators, and process engineers involved in the development of lyophilized protein drug products.

Histidine as a versatile excipient in the protein-based biopharmaceutical formulations

Adequate stabilization is essential for marketed protein-based biopharmaceutical formulations to withstand the various stresses that can be exerted during the pre- and post-manufacturing processes. Therefore, a suitable choice of excipient is a significant step in the manufacturing of such delicate products. Histidine, an essential amino acid, has been extensively used in protein-based biopharmaceutical formulations. The physicochemical properties of histidine are unique among amino acids and could afford multifaceted benefits to protein-based biopharmaceutical formulations. With a pKa of approximately 6.0 at the side chain, histidine has been primarily used as a buffering agent, especially for pH 5.5-6.5. Additionally, histidine exhibited several affirmative properties similar to those of carbohydrates (e.g., sucrose and trehalose) and could therefore be considered to be an alternative approach to established protein-based formulation strategies. The current review describes the general physicochemical properties of histidine, lists all commercial histidine-containing protein-based biopharmaceutical products, and discusses a brief outline of the existing research focused on the versatile applications of histidine, which can act as a buffering agent, stabilizer, cryo-/lyo-protectant, antioxidant, viscosity reducer, and solubilizing agent. The interaction between histidine and proteins in protein-based biopharmaceutical formulations, such as the Donnan effect during diafiltration of monoclonal antibody solutions and the degradation of polysorbates in histidine buffer, has also been discussed. As the first review of histidine in protein biopharmaceuticals, it helps to deepen our understanding of the opportunities and challenges associated with histidine as an excipient for protein-based biopharmaceutical formulations.

Exploring conventional and emerging dehydration technologies for slurry/liquid food matrices and their impact on porosity of powders: A comprehensive review

The contribution of dehydration to the growing market of food powders from slurry/liquid matrices is inevitable. To overcome the challenges posed by conventional drying technologies, several innovative approaches have emerged. However, industrial implementation is limited due to insufficient information on the best-suited drying technologies for targeted products. Therefore, this review aimed to compare various conventional and emerging dehydration technologies (such as active freeze, supercritical, agitated thin-film, and vortex chamber drying) based on their fundamental principles, potential applications, and limitations. Additionally, this article reviewed the effects of drying technologies on porosity, which greatly influence the solubility, rehydration, and stability of powder. The comparison between different drying technologies enables informed decision-making in selecting the appropriate one. It was found that active freeze drying is effective in producing free-flowing powders, unlike conventional freeze drying. Vortex chamber drying could be considered a viable alternative to spray drying, requiring a compact chamber than the large tower needed for spray drying. Freeze-dried, spray freeze-dried, and foam mat-dried powders exhibit higher porosity than spray-dried ones, whereas supercritical drying produces nano-porous interconnected powders. Notably, several factors like glass transition temperature, drying technologies, particle aggregation, agglomeration, and sintering impact powder porosity. However, some binders, such as maltodextrin, sucrose, and lactose, could be applied in controlled agglomeration to enhance powder porosity. Further investigation on the effect of emerging technologies on powder properties and their commercial feasibility is required to discover their potential in liquid drying. Moreover, utilizing clean-label drying ingredients like dietary fibers, derived from agricultural waste, presents promising opportunities.