Nucleic acid therapeutics have emerged as the third major class of therapeutics, following small molecules and antibodies. Lipid nanoparticles (LNPs) serve as the leading platform for nucleic acid delivery. The mRNA-LNPs showed clinical success in COVID-19 vaccines, but they suffer from ultra-low temperature storage requirement that limits global transportation and distribution. Drying technologies, especially freeze-drying, offer solutions to maintain stability at a higher temperature. This review highlights the intrinsic stability of mRNA-LNPs, the status of using freeze-drying for improving the stability of mRNA-LNPs, the potential challenges during freeze-drying, and the strategies for maintaining the stability of mRNA-LNPs during freeze-drying and storage. Beyond mRNA, we compare drying strategies for other nucleic acid-LNPs (NA-LNPs), including siRNA, saRNA, circRNA, pDNA, miRNA, and the CRISPR system, underscoring the impact of structure on the drying of these NA-LNPs. We also discuss alternative freeze-drying and drying methods, including continuous freeze-drying based on spin-freezing, thin film freeze-drying, spray freeze-drying, spray drying, and alcohol dilution freeze-drying, for improving stability and suitability for different routes of administration. Overall, this review provides insight for the development of a solid form of NA-LNPs with maintained stability and potency.

Orally disintegrating tablets (ODTs) are a solid oral dosage form designed to rapidly disintegrate in the mouth without the need for water, improving patient compliance—particularly among pediatric, geriatric, and dysphagic populations. Despite their advantages, ODTs pose formulation and regulatory challenges due to their unique administration characteristics and potential for pregastric absorption. This review examines the regulatory approval pathways for ODTs, including 505(B)(1), 505(B)(2), 505(J), and 505(J)(2)(C), and highlights examples of marketed ODT products approved through each pathway. The differences in in-vivo absorption behavior between ODTs and conventional tablets are discussed, including their influence on pharmacokinetic parameters such as Cmax, Tmax, and AUC. Emphasis is placed on the impact of water co-administration on ODT bioavailability, where factors like fluid volume and administration route can alter drug dissolution and absorption. This paper evaluates product-specific guidances (PSGs) and reference listed drug (RLD) labeling for 39 ODT products approved before the release of the FDA’s guidance, M13A guidance on Bioequivalence for Immediate-Release Solid Oral Dosage Forms. Of these, 17 ODT PSGs recommended different instruction for administration of water than that from their respective product labeling. These PSGs were subsequently updated to align with FDA M13A guidance recommendations. Lastly, this paper provides a comprehensive framework for optimizing bioequivalence assessments of ODTs and supports future development of ODT formulations for new and generic drugs.

Abstract Recent advancements in freeze-drying (lyophilization) have led to the creation of lyophilized PCR mixes. The lyophilized cake or bead offers benefits compared to liquid formulations including extended shelf lives and room-temperature storage, but they come with a number of challenges. Lyophilization is incompatible with certain chemical compounds and biological materials limiting the range of components that can be co-formulated. Formulation optimization and long drying cycles are required, resulting in increased costs. To address these challenges, we developed capillary-assisted vitrification (CAV) (formerly called capillary mediated vitrification (CMV)) and reported its capability to rapidly stabilize different biomolecules without freezing, in a short period (1–3 h cycle time) and with improved thermal stability. In this study, we sought to evaluate the efficiency of CAV to stabilize probe qPCR mixes and to compare the performance of CAV-stabilized PCR mixes with lyophilized mixes using Monkeypox (Mpox) virus DNA as a template. Both CAV-stabilized and lyophilized samples observed similar coefficients of determination (R² = 0.99), with amplification efficiencies of 99% for the lyophilized and 105% for the CAV samples. The analytical limit of detection was 5 copies/reaction for the CAV sample and 10 copies/reaction for the lyophilized sample. Both stabilization reagents showed acceptable variability, with coefficients of inter-assay precision under 2.5%. As expected, CAV-stabilized and lyophilized reagents showed undetermined cycle threshold (Ct) values when no template control was used. Additionally, comparable amplification and Ct values were observed for both CAV-stabilized and lyophilized PCR mix when stored at 37 °C for 26 weeks and 50 °C for 4 weeks. In conclusion, CAV- stabilized PCR mix without freezing, in a shorter cycle, and its performance and stability were comparable to that of lyophilized reagent. The study recommends the CAV process could be an alternative to complex lyophilization for stabilizing PCR reagents.

Abstract This study investigates the phase behavior of Poloxamer 188 (P188) in aqueous solutions under conditions typical of pharmaceutical lyophilization processes. We utilized heat flux sensors (HFSs) in a freeze-dryer and replicated lyophilization processes using a miniaturized setup in an XRPD climate chamber. HFS data from vials in the freeze-dryer indicated not only the primary crystallization of ice but also detected the secondary crystallization of the P188-water system. This was possible when primary ice nucleation was well-controlled and consistent across all vials, ensuring that primary crystallization signals didn’t overshadow those from secondary crystallization. Our findings reveal that P188 crystallization in aqueous systems is generally slow. Measurements in the XRPD climate chamber, involving a P188-based placebo solution, demonstrated that only a small portion of P188 crystallizes during the annealing step. The majority of P188 crystallizes during the primary drying step, concurrently with ice sublimation. Additional crystallization of P188 is observed even at the final secondary drying stage. These insights provide a valuable foundation for optimizing industrial lyophilization processes for Poloxamer-based lyophilizates. Graphical Abstract This study explores Poloxamer 188 crystallization during typical freeze-drying conditions for biologics. Heat flux sensors and an XRPD climate chamber reveal that P188 crystallizes quite slowly. Insights inform optimization of lyophilization processes of P188-containing formulations.

Abstract Purpose Topical local anesthetics have become increasingly important with the recent development of laser therapy. Lidocaine, the most commonly used anesthetic in clinical practice, not only has analgesic effects but also possesses properties such as suppression of neonatal seizures and antiarrhythmic, anti-inflammatory, antibacterial, and antifungal effects. This study aimed to improve the solubility and permeability of lidocaine (Lid) by preparing solid dispersions of Lid and ascorbic acid 2-glucoside (AG) and evaluating their physicochemical properties, solubility, and permeability. Methods Here, we evaluated the physicochemical properties and solubility of solid dispersions of Lid and AG prepared by freeze-drying (freeze-dried [FD] Lid/SSA = 1/1). Results For Differential scanning calorimetry measurements revealed the disappearance of the endothermic peaks associated with the melting of Lid and AG in the freeze-dried formulation (FD) (Lid/AG = 1/1), with the emergence of a new glass transition point. Powder X-ray diffraction measurements confirmed the absence of the characteristic peaks of both Lid and AG in the FD (Lid/AG = 1/1), showing a halo pattern. Near-infrared measurements indicated peak shifts and broadening of the -CH and -NH groups of Lid and the -OH and -CH groups of AG in the FD (Lid/AG = 1/1), suggesting the involvement of complex formation. Solubility tests revealed that the solubility of FD (Lid/AG = 1/1) was approximately 220 mg/mL, which is approximately 50 times higher than that of Lid (approximately 4.0 mg/mL). Nuclear Overhauser effect spectroscopy nuclear magnetic resonance (NMR) measurements revealed cross-peaks between the -CH groups of Lid and the -OH groups of AG, suggesting intermolecular interactions via hydrogen bonding. Diffusion-ordered spectroscopy NMR measurements showed that the diffusion coefficients of Lid and AG in the FD (Lid/AG = 1/1) converged, indicating that the formation of a complex with AG altered the dispersion behavior of Lid in the solvent. In the silicon membrane permeability test, the cumulative amount permeated after 24 h was approximately 700 µg/cm 2 for Lid, compared to approximately 4.0 µg/cm 2 for FD (Lid/AG = 1/1), suggesting that membrane permeability was inhibited. Conclusion These findings suggest that complex formation occurred in FD Lid/ AG; this enhanced the solubility, membrane permeability was inhibited of this dispersion. Graphical Abstract

Coprocessing involves integration of multiple substances to improve the physical, chemical, mechanical, and biopharmaceutical properties of a material. Coprocessing is a promising technique in the pharmaceutical industry which support both drug substance and drug product processes. When active pharmaceutical ingredients (APIs) are coprocessed with excipients, it can enable direct compression and continuous manufacturing. Hydroxypropyl cellulose (HPC-L), a commonly used excipient in pharmaceutical formulations, can enhance drug stability, solubility, and bioavailability. In this study, we have employed coprecipitation (CPT) to coprocess metformin hydrochloride (MET) with HPC-L, resulting in the formation of agglomerates with improved physical attributes without any risk of polymorphic changes. Acetone/acetonitrile and heptane were used as solvent and antisolvent, respectively. Screening study revealed that the use of a rotor stator helps to control the size of metformin hydrochloride and HPC-L agglomerates (M-CPT) without negatively impacting bulk density and powder flow properties. The CPT agglomerates showed residual solvent levels within the specified ICH limits. Powder rheology results demonstrated a sixfold increase in FFC of M-CPT compared to neat MET. The compressibility, tabletability, compactability, and “In-Die” Heckel analysis data further suggested that the M-CPT agglomerates are directly compressible with no observable changes in the dissolution profile of MET. Overall, this study demonstrates application of CPT approach to tune the physical and mechanical properties, and HPC-L can be used as an excipient of choice for CPT technique to improve the compressibility and flowability of APIs.Graphical

Infectious and cancerous diseases are tedious to manage. The problem of drug resistance is often associated with anti-microbial and anti-cancer agents and is one of the most significant challenges that restrict their activity. Therefore, it is necessary to increase doses or drug combinations. However, introducing drugs in this way is often ineffective due to poor solubility, low bioavailability, reduced stability, and different drug pharmacokinetic parameters. Vesicular nanocarriers are considered promising for effective drug delivery and overcoming drug resistance. Lipid-based drug delivery systems (LBDDS) such as emulsomes (EMLs) can solve many problems associated with drug physicochemical properties. EMLs share structural similarities with liposomes and solid lipid nanoparticles (SLNs). The main components of emulsomal preparation are triglycerides (TG), phospholipids (PC), and cholesterol (Chol). These systems provide greater stability and pharmacokinetic parameters in vivo compared to liposomes and other lipid-based systems, overcoming their limitations and surpassing their shortcomings. This review offers a broad summary of emulsomal research to date and a comprehensive overview of the formulation materials and their effects on the fabrication, physical characteristics, surface modification, lymphatic targeting, and recent applications of EMLs in infectious and cancerous diseases. EMLs can offer stable and safe lipid-based systems with adequate entrapment and sustained release properties, improving bioavailability and evading multidrug resistance. Furthermore, they hold promise for future clinical applications for anti-microbial and anti-cancer drugs.Graphical