Comparison of mechanochemical methods in the synthesis of binaphthol-benzoquinone based cocrystals.

Mechanochemical methods either under neat or liquid assisted conditions have proven to be successful in making cocrystals. In this paper we compare the outcome of cocrystallization using two different mechanochemical methods, ball milling (BM) and resonant acoustic mixing (RAM), with solution crystallization. Racemic binaphthol and benzoquinone based binary and ternary cocrystals were investigated by BM and RAM. Both mechanochemical methods were successful in making the binary and ternary cocrystals that have been observed in solid state and solution. It is shown that the type of mechanochemical force imparted to the sample is very different between BM and RAM and this in turn leads to different cocrystallization outcomes. Thus, different mechanochemical methods should not be treated as the same and care must be taken when choosing a mechanochemical method for a particular application.

The effect of unloading and ejection conditions on the properties of pharmaceutical tablets.

This study investigates decompression and ejection conditions on tablet characteristics by comparing compact densities and tensile strengths made using regular rigid dies and custom-built die systems that enable triaxial decompression. Die-wall pressure evolution during decompression and ejection stresses did not meaningfully impact the density and tensile strength of the materials tested: microcrystalline cellulose, crystalline lactose monohydrate, and mannitol. Furthermore, the apparent differences in tensile strength between rectangular cuboids and cylindrical compacts are unrelated to decompression and ejection conditions, but rather a consequence of their shapes and of the test configurations. This suggests that elastic and plastic deformations that may occur during decompression and ejection are not significantly influenced by die-wall pressure evolution. We thus conclude that while triaxial decompression and constraint-free ejection may allow the production of defect-free compacts for materials that otherwise are defect prone using a rigid die, they seem to pose no benefits when the materials already produce defect-free compacts using a rigid die.

Drug-Polymer Nanodroplet Formation and Morphology Drive Solubility Enhancement of GDC-0810.

Nanodroplet formation is important to achieve supersaturation of active pharmaceutical ingredients (APIs) in an amorphous solid dispersion. The aim of the current study was to explore how polymer composition, architecture, molar mass, and surfactant concentration affect polymer-drug nanodroplet morphology with the breast cancer API, GDC-0810. The impact of nanodroplet size and morphology on dissolution efficacy and drug loading capacity was explored using polarized light microscopy, dynamic light scattering, and cryogenic transmission electron microscopy. Poly(N-isopropylacrylamide-stat-N,N-dimethylacrylamide) (PND) was synthesized as two linear derivatives and two bottlebrush derivatives with carboxylated or PEGylated end-groups. Hydroxypropyl methylcellulose acetate succinate grade MF (HPMCAS-MF) and poly(vinylpyrrolidone-co-vinyl acetate) (PVPVA) were included as commercial polymer controls. We report the first copolymerization synthesis of a PVPVA bottlebrush copolymer, which was the highest performing excipient in this study, maintaining 688 µg/mL GDC-0810 concentration at 60 wt % drug loading. This is likely due to strong polymer-drug noncovalent interactions and the compaction of GDC-0810 along the PVPVA bottlebrush backbone. Overall, it was observed that the most effective formulations had a hydrodynamic radius less than 25 nm with tightly compacted nanodroplet morphologies.

Evaluating Utilization of Tiny-TIM to Assess the Effect of Food on the Absorptions of Oral Drugs and Its Application on Biopharmaceutical Modeling.

Safety and efficacy are the most critical factors for the development of modern medications. For oral drugs, evaluating drug exposure under various conditions is one of the most important outcomes for clinical trials. These data will help to better understand the safety and efficacy of new drugs. Studies involving potential drug-drug interactions, proton pump inhibitors, and intake of food are often conducted to assess the above. Among the above, the influence of food on exposure to the drug is one of the key data sets for regulatory submission. Since food may have either a positive or negative effect on drug exposure, it is important to obtain an early assessment of the food effect. To better forecast and plan for clinical studies, substantial efforts have been made in the industry to develop modeling and in-vitro and in-vivo assays. Despite the efforts, predicting the effect of food on exposure without integrating the dynamic of the gastrointestinal tract in the assessment remains challenging. In this study, we evaluated the utilization of the dynamic Gastro-Intestinal Model (Tiny-TIM) for the food effect of over 20 drugs/formulations in development or on the market that covers all BCS classes. In general, the Tiny-TIM predicted food effects were in good agreement with the reported data in humans. This suggests that Tiny-TIM can successfully capture the impact of physicochemical properties on absorption under the influence of food.

Inhaled JAK Inhibitor GDC-0214 Nanoaggregate Powder Exhibits Improved Pharmacokinetic Profile in Rats Compared to the Micronized Form: Benefits of Thin Film Freezing.

Asthma is a common chronic disease affecting the airways in the lungs. The receptors of allergic cytokines, including interleukin (IL)-4, IL-5, and IL-13, trigger the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, which involves the pathogenesis of asthma. GDC-0214 is a JAK inhibitor that was developed as a potent and selective target for the treatment of asthma, specifically targeting the lungs. While inhaled GDC-0214 is a promising novel treatment option against asthma, improvement is still needed to achieve increased potency of the powder formulation and a reduced number of capsules containing powder to be inhaled. In this study, high-potency amorphous powder formulations containing GDC-0214 nanoaggregates for dry powder inhalation were developed using particle engineering technology, thin film freezing (TFF). A high dose per capsule was successfully achieved by enhancing the solubility of GDC-0214 and powder conditioning. Lactose and/or leucine as excipients exhibited optimum stability and aerosolization of GDC-0214 nanoaggregates, and aerosolization of the dose was independent of air flow through the device between 2 and 6 kPa pressure drops. In the rat PK study, formulation F20, which contains 80% GDC-0214 and 20% lactose, resulted in the highest AUC0-24h in the lungs with the lowest AUC0-24h in the plasma that corresponds to a 4.8-fold higher ratio of the lung-to-plasma exposures compared to micronized crystalline GDC-0214 powder administered by dry powder inhalation. Therefore, GDC-0214 nanoaggregates produced by TFF provided an improved dry powder for inhalation that can lead to enhanced therapeutic efficacy with a lower risk of systemic toxicity.

Predicting Long-Term Stability of an Oral Delivered Antibody Drug Product with Accelerated Stability Assessment Program Modeling.

The oral delivery of protein therapeutics offers numerous advantages for patients but also presents significant challenges in terms of development. Currently, there is limited knowledge available regarding the stability and shelf life of orally delivered protein therapeutics. In this study, a comprehensive assessment of the stability of an orally delivered solid dosage variable domain of heavy-chain antibody (VHH antibody) drug product was conducted. Four stability related quality attributes that undergo change as a result of thermal and humidity stress were identified. Subsequently, these attributes were modeled using an accelerated stability approach facilitated by ASAPprime software. To the best of our knowledge, this is the first time that this approach has been reported for an antibody drug product. We observed overall good model quality and accurate predictions regarding the protein stability during storage. Notably, we discovered that protein aggregation, formed through a degradation pathway, requires additional adjustments to the modeling method. In summary, the ASAP approach demonstrated promising results in predicting the stability of this complex solid-state protein formulation. This study sheds light on the stability and shelf life of orally delivered protein therapeutics, addressing an important knowledge gap in the field.

Probing the Protein-Excipient Interaction in the Orally Delivered Protein by Solid-State Hydrogen-Deuterium Exchange Mass Spectrometry and Molecular Dynamics.

The oral administration of protein therapeutics in solid dosage form is gaining popularity due to its benefits, such as improved medication adherence, convenience, and ease of use for patients compared to traditional parental delivery. However, formulating oral biologics presents challenges related to pH barriers, enzymatic breakdown, and poor bioavailability. Therefore, understanding the interaction between excipients and protein therapeutics in the solid state is crucial for formulation development. In this Letter, we present a case study focused on investigating the role of excipients in protein aggregation during the production of a solid dosage form of a single variable domain on a heavy chain (VHH) protein. We employed solid-state hydrogen-deuterium exchange coupled with mass spectrometry (ssHDX-MS) at both intact protein and peptide levels to assess differences in protein-excipient interactions between two formulations. ssHDX-MS analysis revealed that one formulation effectively prevents protein aggregation during compaction by blocking ß-sheets across the VHH protein, thereby preventing ß-sheet-ß-sheet interactions. Spatial aggregation propensity (SAP) mapping and cosolvent simulation from molecular dynamics (MD) simulation further validated the protein-excipient interaction sites identified through ssHDX-MS. Additionally, the MD simulation demonstrated that the interaction between the VHH protein and excipients involves hydrophilic interactions and/or hydrogen bonding. This novel approach holds significant potential for understanding protein-excipient interactions in the solid state and can guide the formulation and process development of orally delivered protein dosage forms, ultimately enhancing their efficacy and stability.

Comparative Evaluation of Particle Size Reduction, Salt Formation, and Amorphous Formulation on the Biopharmaceutical Performance of a Weak Base Drug Candidate.

Various approaches have been developed to enhance the solubility or dissolution rate for the delivery of poorly water-soluble molecules. In this work, guided by an in silico solubility sensitivity analysis for oral absorption, a comparative assessment of the biopharmaceutical performance of a jet-milled free base, a tosylate salt, and a 50:50 (w/w) amorphous solid dispersion (ASD) with hydroxypropyl methylcellulose acetate succinate (HPMCAS) of a weak base drug candidate, GDC-3280, was conducted. Successful particle size reduction without amorphization or form change was confirmed for the jet-milled free base. The potential of solubility enhancement and desupersaturation risk were identified for tosylate salt and ASD formulation by measurements of tosylate salt solubility product constant (Ksp) and amorphous solubility of GDC-3280. In vitro dissolution testing demonstrated dissolution rate improvement for the jet-milled free base when compared with the unmilled free base and confirmed solubility enhancement followed by desupersaturation for GDC-3280 tosylate salt and ASD formulation. A crystallization inhibitor, hydroxypropyl methylcellulose (HPMC), was found to slow down the desupersaturation of tosylate salt solution, providing general insights for the development of pharmaceutical salts with disproportionation risks. Finally, a pharmacokinetic study in dogs showed that the in vivo exposure increased by 1.7- to 2-fold for the tosylate salt and ASD formulation compared with the jet-milled free base, consistent with the in silico solubility sensitivity analysis for the fraction of drug absorbed. Overall, this work provides insights into the evaluation of multiple formulation approaches for enhancing the biopharmaceutical performance of poorly water-soluble drugs.

Direct mechanocatalysis by resonant acoustic mixing (RAM).

We demonstrate the use of a metal surface to directly catalyse copper-catalysed alkyne-azide click-coupling (CuAAC) reactions under the conditions of Resonant Acoustic Mixing (RAM) - a recently introduced and scalable mechanochemical methodology that uniquely eliminates the need for bulk solvent, as well as milling media. By using a simple copper coil as a catalyst, this work shows that direct mechanocatalysis can occur in an impact-free environment, relying solely on high-speed mixing of reagents against a metal surface, without the need for specially designed milling containers and media. By introducing an experimental setup that enables real-time Raman spectroscopy monitoring of RAM processes, we demonstrate 0th-order reaction kinetics for several selected CuAAC reactions, supporting surface-based catalysis. The herein presented RAM-based direct mechanocatalysis methodology is simple, enables the effective one-pot, two-step synthesis of triazoles via a combination of benzyl azide formation and CuAAC reactions on a wide scope of reagents, provides control over reaction stoichiometry that is herein shown to be superior to that seen in solution or by using more conventional CuCl catalyst, and is applied for simple gram-scale synthesis of the anticonvulsant drug Rufinamide.

Correlating the Structure and Gene Silencing Activity of Oligonucleotide-Loaded Lipid Nanoparticles Using Small-Angle X-ray Scattering.

With three FDA-approved products, lipid nanoparticles (LNPs) are under intensive development for delivering wide-ranging nucleic acid therapeutics. A significant challenge for LNP development is insufficient understanding of structure-activity relationship (SAR). Small changes in chemical composition and process parameters can affect LNP structure, significantly impacting performance in vitro and in vivo. The choice of polyethylene glycol lipid (PEG-lipid), one of the essential lipids for LNP, has been proven to govern particle size. Here we find that PEG-lipids can further modify the core organization of antisense oligonucleotide (ASO)-loaded LNPs to govern its gene silencing activity. Furthermore, we also have found that the extent of compartmentalization, measured by the ratio of disordered vs ordered inverted hexagonal phases within an ASO-lipid core, is predictive of in vitro gene silencing. In this work, we propose that a lower ratio of disordered/ordered core phases correlates with stronger gene knockdown efficacy. To establish these findings, we developed a seamless high-throughput screening approach that integrated an automated LNP formulation system with structural analysis by small-angle X-ray scattering (SAXS) and in vitro TMEM106b mRNA knockdown assessment. We applied this approach to screen 54 ASO-LNP formulations while varying the type and concentration of PEG-lipids. Representative formulations with diverse SAXS profiles were further visualized using cryogenic electron microscopy (cryo-EM) to help structural elucidation. The proposed SAR was built by combining this structural analysis with in vitro data. Our integrated methods, analysis, and resulting findings on PEG-lipid can be applied to rapidly optimize other LNP formulations in a complex design space.

Development of an Amorphous Solid Dispersion Formulation for Mitigating Mechanical Instability of Crystalline Form and Improving Bioavailability for Early Phase Clinical Studies.

In this work, an amorphous solid dispersion (ASD) formulation was systematically developed to simultaneously enhance bioavailability and mitigate the mechanical instability risk of the selected crystalline form of a development drug candidate, GDC-0334. The amorphous solubility advantage calculation was applied to understand the solubility enhancement potential by an amorphous formulation for GDC-0334, which showed 2.7 times theoretical amorphous solubility advantage. This agreed reasonably well with the experimental solubility ratio between amorphous GDC-0334 and its crystalline counterpart (∼2 times) in buffers of a wide pH range. Guided by the amorphous solubility advantage, ASD screening was then carried out, focusing on supersaturation maintenance and dissolution performance. It was found that although the type of polymer carrier did not impact ASD performance, the addition of 5% (w/w) sodium dodecyl sulfate (SDS) significantly improved the GDC-0334 ASD dissolution rate. After ASD composition screening, stability studies were conducted on selected ASD powders and their hypothetical tablet formulations. Excellent stability of the selected ASD prototypes with or without tablet excipients was observed. Subsequently, ASD tablets were prepared, followed by in vitro and in vivo evaluations. Similar to the effect of facilitating the dissolution of ASD powders, the added SDS improved the disintegration and dissolution of ASD tablets. Finally, a dog pharmacokinetic study confirmed 1.8 to 2.5-fold enhancement of exposure by the developed ASD tablet over the GDC-0334 crystalline form, consistent with the amorphous solubility advantage of GDC-0334. A workflow of developing an ASD formulation for actual pharmaceutical application was proposed according to the practice of this work, which could provide potential guidance for ASD formulation development in general for other new chemical entities.

Formulation and Scale-Up of Fast-Dissolving Lumefantrine Nanoparticles for Oral Malaria Therapy.

Lumefantrine (LMN) is one of the first-line drugs in the treatment of malaria due to its long circulation half-life, which results in enhanced effectiveness against drug-resistant strains of malaria. However, LMN's therapeutic efficacy is diminished due to its low bioavailability when dosed as a crystalline solid. The goal of this work was to produce low-cost, highly bioavailable, stable LMN powders for oral delivery that would be suitable for global health applications. We report the development of a LMN nanoparticle formulation and the translation of that formulation from laboratory to industrial scale. We applied Flash NanoPrecipitation (FNP) to develop nanoparticles with 90% LMN loading and sizes of 200-260 nm. The integrated process involves nanoparticle formation, concentration by tangential flow ultrafiltration, and then spray drying to obtain a dry powder. The final powders are readily redispersible and stable over accelerated aging conditions (50°C, 75% RH, open vial) for at least 4 weeks and give equivalent and fast drug release kinetics in both simulated fed and fasted state intestinal fluids, making them suitable for pediatric administration. The nanoparticle-based formulations increase the bioavailability of LMN 4.8-fold in vivo when compared to the control crystalline LMN. We describe the translation of the laboratory-scale process at Princeton University to the clinical manufacturing scale at WuXi AppTec.

Exploring the Use of a Kinetic pH Calculation to Correct the ACAT Model with a Single Stomach Compartment Setting: Impact of Stomach Setting on Food Effect Prediction for Basic Compounds.

Advanced compartmental absorption and transit (ACAT) based computational models have become increasingly popular in the industry for predicting oral drug product performance. However, due to its complexity, some compromises have been made in practice, and the stomach is often assigned as a single compartment. Although this assignment worked generally, it may not be sufficient to reflect the complexity of the gastric environment under certain conditions. For example, this setting was found to be less accurate in estimating stomach pH and solubilization of certain drugs under food intake, which leads to a misprediction of the food effect. To overcome the above, we explored the use of a kinetic pH calculation (KpH) for the single-compartment stomach setting. Several drugs have been tested with the KpH approach and compared with the default setting of Gastroplus. In general, the Gastroplus prediction of food effect is greatly improved, suggesting this approach is effective in improving the estimation of physicochemical properties related to food effect for several basic drugs by Gastroplus.

Resonant acoustic mixing (RAM) for efficient mechanoredox catalysis without grinding or impact media.

Resonant acoustic mixing (RAM) enables mechanoredox catalysis with BaTiO3 as the piezoelectric catalyst on model diazonium coupling reactions. RAM proceeds without formal grinding or impact media, is faster than the analogous ball-milling strategy, and is readily scalable. X-ray diffraction and spectroscopy indicate that reusability of BaTiO3 as a mechanoredox catalyst under ball-milling or RAM might be limited by boration.

The "η-sweet-spot" (ηmax) in liquid-assisted mechanochemistry: polymorph control and the role of a liquid additive as either a catalyst or an inhibitor in resonant acoustic mixing (RAM).

Resonant acoustic mixing (RAM) offers a simple, efficient route for mechanochemical synthesis in the absence of milling media or bulk solvents. Here, we show the use of RAM to conduct the copper-catalysed coupling of sulfonamides and carbodiimides. This coupling was previously reported to take place only by mechanochemical ball milling, while in conventional solution environments it is not efficient, or does not take place at all. The results demonstrate RAM as a suitable methodology to conduct reactions previously accessed only by ball milling and provide a detailed, systematic overview of how the amount of liquid additive, measured by the ratio of liquid volume to weight of reactants (η, in µL mg-1), can affect the course of a mechanochemical reaction and the polymorphic composition of its product. Switching from ball milling to RAM allowed for the discovery of a new polymorph of the model sulfonylguanidine obtained by catalytic coupling of di(cyclohexyl)carbodiimide (DCC) and p-toluenesulfonamide, and the ability to control reaction temperature in RAM enabled in situ control of the polymorphic behaviour of this nascent product. We show that the reaction conversion for a given reaction time does not change monotonically but, instead, achieves a maximum for a well-defined η-value. This "η-sweet-spot" of conversion is herein designated ηmax. The herein explored reactions demonstrate sensitivity to η on the order of 0.01 µL mg-1, which corresponds to an amount of liquid additive below 5 mol% compared to the reactants, and is at least one to two orders of magnitude lower than the η-value typically considered in the design of liquid-assisted ball milling mechanochemical reactions. Such sensitivity suggests that strategies to optimise liquid-assisted mechanochemical reactions should systematically evaluate η-values at increments of 0.01 µL mg-1, or even finer. At η-values other than ηmax the reaction conversion drops off, demonstrating that the same liquid additive can act either as a catalyst or an inhibitor of a mechanochemical reaction, depending on the amount.