Dissolution Mechanisms of Amorphous Solid Dispersions: Application of Ternary Phase Diagrams To Explain Release Behavior.

The use of amorphous solid dispersions (ASDs) in commercial drug products has increased in recent years due to the large number of poorly soluble drugs in the pharmaceutical pipeline. However, the release behavior of ASDs is complex and remains not well understood. Often, the drug release from ASDs is rapid and complete at lower drug loadings (DLs) but becomes slow and incomplete at higher DLs. The DL where release becomes hindered is termed the limit of congruency (LoC). Currently, there are no approaches to predict the LoC. However, recent findings show that one potential cause leading to the LoC is a change in phase morphology after water-induced phase separation at the ASD/solution interface. In this study, the phase behavior of ASDs in contact with aqueous solutions was described thermodynamically by constructing experimental and computational ternary phase diagrams, and these were used to predict morphology changes and ultimately the LoC. Experimental ternary phase diagrams were obtained by equilibrating ASD/water mixtures over time. Computational ternary phase diagrams were obtained by Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT). The morphology of the hydrophobic phase was studied with fluorescence confocal microscopy. It was demonstrated that critical point (plait point) composition approximately corresponded to the ASD DL, where the hydrophobic phase, formed during phase separation, became interconnected and hindered ASD release. This work provides mechanistic insights into the ASD release behavior and highlights the potential of in silico ASD design using phase diagrams.

Reductive amination of oxidized hydroxypropyl cellulose with ω-aminoalkanoic acids as an efficient route to zwitterionic derivatives.

Zwitterionic polymers, with their equal amounts of cationic and anionic functional groups, have found widespread utility including as non-fouling coatings, hydrogel materials, stabilizers, antifreeze materials, and drug carriers. Polysaccharide-derived zwitterionic polymers are attractive because of their sustainable origin, potential for lower toxicity, and possible biodegradability, but previous methods for synthesis of zwitterionic polysaccharide derivatives have been limited in terms of flexibility and attainable degree of substitution (DS) of charged entities. We report herein successful design and synthesis of zwitterionic polysaccharide derivatives, in this case based on cellulose, by reductive amination of oxidized 2-hydroxypropyl cellulose (Ox-HPC) with ω-aminoalkanoic acids. Reductive amination products could be readily obtained with DS(cation) (= DS(anion)) up to 1.6. Adduct hydrophilic/hydrophobic balance (amphiphilicity) can be influenced by selecting the appropriate chain length of the ω-aminoalkanoic acid. This strategy is shown to produce a range of amphiphilic, water-soluble, moderately high glass transition temperature (Tg) polysaccharide derivatives in just a couple of efficient steps from commercially available building blocks. The adducts were evaluated as crystallization inhibitors. They are strong inhibitors of crystallization even for the challenging, poorly soluble, fast-crystallizing prostate cancer drug enzalutamide, as supported by surface tension and Flory-Huggins interaction parameter results.

Prokinetics for the treatment of functional dyspepsia: an updated systematic review and network meta-analysis.

BACKGROUND: Since the previous network meta-analysis assessing the efficacy of prokinetics for functional dyspepsia (FD), there have been a number of new studies and cinitapride is a new prokinetic agent for FD. This updated meta-analysis aimed to explore the efficacy and safety of prokinetics for FD. METHODS: An updated study search in Pubmed, EMBASE, Cochrane Library and Web of Science was conducted in literatures published from July 2015 to March 2023. Randomized controlled trials investigating the use of prokinetics in adult FD patients were included. The primary outcome was the total efficacy rate and the secondary outcome was adverse events. A Bayesian network meta-analysis was performed using R software. RESULTS: A total of 28 studies were included. Network meta-analysis showed that metoclopramide had a higher total efficacy rate than mosapride (OR: 3.53, 95%CI: 1.70-7.47), domperidone (OR: 2.29, 95%CI: 1.16-4.63), itopride(OR: 2.77, 95%CI: 1.41-5.59), acotiamide(OR: 2.63, OR: 1.33-5.36), and placebo(OR: 5.68, 95%CI: 2.98-11.10), however similar to cinitapride (OR: 1.62, 95%CI: 0.75-3.53). Cinitapride had a higher total efficacy rate than mosapride (OR: 2.18, 95%CI: 1.16-4.14) and placebo (OR: 3.52, 95%CI: 2.01-6.24). Cinitapride had lower risk of total adverse events than domperidone. There was no difference in the risk of drug-related adverse events between the prokinetics. CONCLUSIONS: Metoclopramide and cinitapride may have a better efficacy than other prokinetics in the treatment of FD, and cinitapride may have a lower risk of total adverse events. Further studies using uniform definitions or validated tools to measure the total efficacy rate are needed.

Goblet cells segmentation from confocal laser endomicroscopy with an improved U-Net.

Gastric intestinal metaplasia (GIM) is regarded as a remarkable precursor for the development of intestinal-type stomach cancer. Goblet cell (GC) segmentation is the crucial step for assessing the degree of GIM by confocal laser endomicroscopy (CLE). However, GC segmentation by hand is difficult, unreliable, and time-consuming. Meanwhile, due to the high resolution and noise interference of CLE images, existing segmentation approaches perform poorly on this task. To tackle those issues, we collected 343 confocal laser endomicroscopy images of 62 patients from a Grade-A tertiary hospital. Each CLE image is manually annotated and then verified three times by skilled medical specialists. Then, U-Net is improved by incorporating the pixel gradient attention mechanism, which focuses on color gradient information around GC and captures color gradient features to direct feature maps in the skip connection layer. At last, the model output vector is used to calculate the possibility map and generate the final segmentation area. Compared with mainstream models, our proposed GC segmentation method from CLE with an improved U-Net (GCSCLE) performs the better segmentation result when tested on our CLE dataset and achieved an IOU of 87.95% and a DICE of 86.64%. Our result shows, the performance of the GCSCLE can be compared with the manual CLE image processing in clinical settings, and it can improve segmentation accuracy and save time and costs.

Optimal concentration of Lugol's solution for detecting early esophageal carcinoma: A randomized controlled trial.

BACKGROUND AND AIM: Lugol chromoendoscopy is the standard technique to detect an esophageal squamous cell carcinoma (ESCC). However, a high concentration of Lugol's solution can induce mucosal injury and adverse events. We aimed to investigate the optimal concentration of Lugol's solution to reduce mucosal injury and adverse events without degrading image quality. METHODS: This was a two-phase double-blind randomized controlled trial. In phase I, 200 eligible patients underwent esophagogastroduodenoscopy and then were randomly (1:1:1:1:1) sprayed with 1.2%, 1.0%, 0.8%, 0.6%, or 0.4% Lugol's solution. Image quality, gastric mucosal injury, adverse events, and operation satisfaction were compared to investigate the minimal effective concentration. In phase II, 42 cases of endoscopic mucosectomy for early ESCC were included. The patients were randomly assigned (1:1) to the minimal effective (0.6%) or conventional (1.2%) concentration of Lugol's solution for further comparison of the effectiveness. RESULTS: In phase I, the gastric mucosal injury was significantly reduced in 0.6% group (P < 0.05). Furthermore, there was no statistical significance in image quality between 0.6% and higher concentrations of Lugol's solution (P > 0.05, respectively). It also showed that the operation satisfaction decreased in 1.2% group compared with the lower concentration groups (P < 0.05). In phase II, the complete resection rate was 100% in both groups, while 0.6% Lugol's solution showed higher operation satisfaction (W = 554.500, P = 0.005). CONCLUSIONS: The study indicates that 0.6% might be the optimal concentration of Lugol's solution for early detection and delineation of ESCC, considering minimal mucosal injury and satisfied image. The registry of clinical trials: ClinicalTrials.gov (NCT03180944).

Dissolution Mechanisms of Amorphous Solid Dispersions: A Close Look at the Dissolution Interface.

Despite the recent success of amorphous solid dispersions (ASDs) at enabling the delivery of poorly soluble small molecule drugs, ASD-based dosage forms are limited by low drug loading. This is partially due to a sharp decline in drug release from the ASD at drug loadings surpassing the 'limit of congruency' (LoC). In some cases, the LoC is as low as 5% drug loading, significantly increasing the risk of pill burden. Despite efforts to understand the mechanism responsible for the LoC, a clear picture of the molecular processes occurring at the ASD/solution interface remains elusive. In this study, the ASD/solution interface was studied for two model compounds formulated as ASDs with copovidone. The evolution of a gel layer and its phase behavior was captured in situ with fluorescence confocal microscopy, where fluorescent probes were added to label the hydrophobic and hydrophilic phases. Phase separation was detected in the gel layer for most of the ASDs. The morphology of the hydrophobic phase was found to correlate with the release behavior, where a discrete phase resulted in good release and a continuous phase formed a barrier leading to poor release. The continuous phase formed at a lower drug loading for the system with stronger drug-polymer interactions. This was due to incorporation of the polymer into the hydrophobic phase. The study highlights the complex molecular and phase behavior at the ASD/solution interface of copovidone-based ASDs and provides a thermodynamic argument for qualitatively predicting the release behavior based on drug-polymer interactions.

Dissolution Mechanisms of Amorphous Solid Dispersions: Role of Drug Load and Molecular Interactions.

High drug load amorphous solid dispersions (ASDs) have been a challenge to formulate partially because drug release is inhibited at high drug loads. The maximum drug load prior to inhibition of release has been termed the limit of congruency (LoC) and has been most widely studied for copovidone (PVPVA)-based ASDs. The terminology was derived from the observation that below LoC, the polymer controlled the kinetics and the drug and the polymer released congruently, while above LoC, the release rates diverged and were impaired. Recent studies show a correlation between the LoC value and drug-polymer interaction strength, where a lower LoC was observed for systems with stronger interactions. The aim of this study was to investigate the causality between drug-PVPVA interaction strength and LoC. Four chemical analogues with diverse abilities to interact with PVPVA were used as model drugs. The distribution of the polymer between the dilute aqueous phase and the insoluble nanoparticles containing drug was studied with solution nuclear magnetic resonance spectroscopy and traditional separation techniques to understand the thermodynamics of the systems in a dilute environment. Polymer diffusion to and from ASD particles suspended in aqueous solution was monitored for drug loads above the LoC to investigate the thermodynamic driving force for polymer release. The surface composition of ASD compacts before and after exposure to buffer was studied with Fourier transform infrared spectroscopy to capture potential kinetic barriers to release. It was found that ASD compacts with drug loads above the LoC formed an insoluble barrier on the surface that was in pseudo-equilibrium with the aqueous phase and prevented further release of drugs and polymers during dissolution. The insoluble barrier contained a substantial amount of the polymer for the strongly interacting drug-polymer systems. In contrast, a negligible amount was found for the weakly interacting systems. This observation provides an explanation for the ability of strongly interacting systems to form an insoluble barrier at lower drug loads. The study highlights the importance of thermodynamic and kinetic factors on the dissolution behavior of ASDs and provides a potential framework for maximizing the drug load in ASDs.

Application of deep learning in the real-time diagnosis of gastric lesion based on magnifying optical enhancement videos.

Background and aim: Magnifying image-enhanced endoscopy was demonstrated to have higher diagnostic accuracy than white-light endoscopy. However, differentiating early gastric cancers (EGCs) from benign lesions is difficult for beginners. We aimed to determine whether the computer-aided model for the diagnosis of gastric lesions can be applied to videos rather than still images. Methods: A total of 719 magnifying optical enhancement images of EGCs, 1,490 optical enhancement images of the benign gastric lesions, and 1,514 images of background mucosa were retrospectively collected to train and develop a computer-aided diagnostic model. Subsequently, 101 video segments and 671 independent images were used for validation, and error frames were labeled to retrain the model. Finally, a total of 117 unaltered full-length videos were utilized to test the model and compared with those diagnostic results made by independent endoscopists. Results: Except for atrophy combined with intestinal metaplasia (IM) and low-grade neoplasia, the diagnostic accuracy was 0.90 (85/94). The sensitivity, specificity, PLR, NLR, and overall accuracy of the model to distinguish EGC from non-cancerous lesions were 0.91 (48/53), 0.78 (50/64), 4.14, 0.12, and 0.84 (98/117), respectively. No significant difference was observed in the overall diagnostic accuracy between the computer-aided model and experts. A good level of kappa values was found between the model and experts, which meant that the kappa value was 0.63. Conclusions: The performance of the computer-aided model for the diagnosis of EGC is comparable to that of experts. Magnifying the optical enhancement model alone may not be able to deal with all lesions in the stomach, especially when near the focus on severe atrophy with IM. These results warrant further validation in prospective studies with more patients. A ClinicalTrials.gov registration was obtained (identifier number: NCT04563416). Clinical Trial Registration: ClinicalTrials.gov, identifier NCT04563416.

Improved dissolution of an enteric polymer and its amorphous solid dispersions by polymer salt formation.

Weakly acidic polymers, historically used as enteric coatings, are increasingly being employed in solubility-enhancing amorphous solid dispersion (ASD) formulations. However, there is a lack of fundamental understanding around how these carboxylic acid-containing polymers dissolve, in particular when molecularly mixed with a lipophilic drug, as in an ASD. Identification of critical factors dominating their dissolution is vital for rational design of new polymers with enhanced release properties to address contemporary ASD delivery challenges, notably achieving good release at higher drug loadings. Herein, after identification of polymer solubilization via ionization as the rate limiting step for dissolution, hydroxypropylmethyl cellulose phthalate (HP-50) was converted to a salt by neutralization of the phthalic acid groups with different bases. Surface normalized dissolution was performed to assess the dissolution rate improvement achieved by polymer pre-ionization via salt formation. Polymer salts showed âˆ¼ 3-fold faster release than HP-50 at pH 6.8 (50 mM sodium phosphate buffer). Importantly, a polymer salt was able to maintain a rapid dissolution rate, irrespective of the buffer capacity of the medium, whereas the protonated polymer showed greatly diminished dissolution as medium buffer capacity decreased toward physiological gastrointestinal tract values. HP-50 and two polymer salts were formulated into ASDs with miconazole, a lipophilic and weakly basic antifungal drug, at a 20% drug loading. Rapid drug release rates were achieved with polymer salt ASDs, whereby drug release was 14 times faster than from the protonated HP-50 ASD. This study highlights the critical role of polymer ionization and buffer capacity in the dissolution of HP-50-based systems and how pre-ionization via polymer salt formation is a successful strategy for the design of new polymers for improved ASD performance.

Designing synergistic crystallization inhibitors: Bile salt derivatives of cellulose with enhanced hydrophilicity.

Crystallization inhibitors in amorphous solid dispersions (ASD) enable metastable supersaturated drug solutions that persist for a physiologically relevant time. Olefin cross-metathesis (CM) has successfully provided multifunctional cellulose-based derivatives as candidate ASD matrix polymers. In proof of concept studies, we prepared hydrophobic bile salt/cellulose adducts by CM with naturally occurring bile salts. We hypothesized that increased hydrophilicity would enhance the ability of these conjugates to maximize bioactive supersaturation. Their selective preparation presents a significant synthetic challenge, given polysaccharide reactivity and polysaccharide and bile salt complexity. We prepared such derivatives using a more hydrophilic hydroxypropyl cellulose (HPC) backbone, employing a pent-4-enyl tether (Pen) for appending bile acids. We probed structure-property relationships by varying the nature and degree of substitution of the bile acid substituent (lithocholic or deoxycholic acid). These conjugates are indeed synergistic inhibitors, as demonstrated with the fast-crystallizing prostate cancer drug, enzalutamide. The lithocholic acid methyl ester derivative, AcrMLC-PenHHPCPen (0.64), increased induction time 68 fold vs. drug alone.

Chemo- and Stereoselective Dearomative Coupling of Indoles and Bielectrophilic ß-Imino Boronic Esters via Imine-Induced 1,2-Boronate Migration.

A new imine-induced 1,2-boronate migration has been developed for achieving chemo- and stereoselective dearomative coupling of C3-substituted indoles and bi-electrophilic ß-imino boronic esters, providing rapid access to complex chiral indoline boronic esters with four stereocenters including an all-carbon quaternary stereocenter and a tertiary α-aminoboronic ester. In contrast, coupling of indoles without C3 substitution and ß-imino boronic esters provided tetrahydro-1H-pyrido[4,3-b]indoles via imine-induced 1,2-boronate migration followed by deborylative rearomatization.

Prognostic Significance of Preoperative Prognostic Nutritional Index for Overall Survival and Postoperative Complications in Esophageal Cancer Patients.

BACKGROUND: Prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) are the most common factors to estimate nutritional and inflammatory status. The aim of this study is to systematically evaluate the prognostic significance of above nutritional and inflammatory indexes for overall survival (OS) and surgical complications in esophageal cancer patients. METHODS: Esophageal cancer patients who underwent esophagectomy were retrospectively collected. PNI, NLR, PLR, and SII were introduced to evaluate the baseline nutritional and inflammatory status. RESULTS: A total of 407 patients were included in the present study. Kaplan-Meier survival analysis revealed that PNI-low group, NLR-high group and PLR-high group, all showed a significantly shorter OS (34.38% vs 49.46%, P < 0.001; 36.13% vs 48.26%, P = 0.026 and 33.33% vs 48.52%, P = 0.001 respectively), while no significant difference was found in SII groups (42.33% vs 46.31%, P = 0.067). Multivariable analyses identified PNI (P = 0.002) was an independent prognostic factor for OS, but NLR (P = 0.672) and PLR (P = 0.186) were not. Postoperative complications occurred significantly more frequently in the low-PNI group (29.69% vs 13.26%, P < 0.001). However, no significant differences were found in the postoperative complication rates between different NLR (16.67% vs 22.69%, P = 0.124), PLR (18.03% vs 19.61%, P = 0.867) and SII (15.34% vs 20.49%, P = 0.326) groups. Multivariate logistic regression analysis showed only PNI (P = 0.008) was an independent prognostic factor for postoperative complications. CONCLUSION: Preoperative low PNI was not only an independent prognostic factor for worse survival in esophageal cancer patients but also associated with high incidence of postoperative complications.

[Prediction of Prenatal Ultrasound Screening Staff's Situation in Beijing Based on ARIMA Model].

Objective To understand the current situation and predict the trends in number and composition of prenatal ultrasound screening staff in Beijing. Methods We analyzed the region,age,professional title and other characteristics of prenatal ultrasound screening personnel in Beijing during 2007-2015.We then built an ARIMA model basing on the current situation to predict the number and composition of the staff in 2016-2020. Results The number of prenatal ultrasound screening staff showed an upward trend in 2007-2020 and was predicted to reach 1269 in 2020.During this period,the educational achievement and professional title of the staff showed a downward trend,and the working years became shorter,mainly below 5 years.The proportion of resident doctors remained at 26.6%,and that of the staff receiving further education would reach 43.2% by the end of 2020. Conclusion The prediction under ARIMA model suggests that efforts should be made to strengthen the training of young doctors and provide them opportunities for further study.

Impact of Drug-Polymer Intermolecular Interactions on Dissolution Performance of Copovidone-Based Amorphous Solid Dispersions.

For poorly soluble drugs formulated as amorphous solid dispersions (ASDs), fast and complete release with the generation of drug-rich colloidal particles is beneficial for optimizing drug absorption. However, this ideal dissolution profile can only be achieved when the drug releases at the same normalized rate as the polymer, also known as congruent release. This phenomenon only occurs when the drug loading (DL) is below a certain value. The maximal DL at which congruent release occurs is defined as the limit of congruency (LoC). The purpose of this study was to investigate the relationship between drug chemical structure and LoC for PVPVA-based ASDs. The compounds investigated shared a common scaffold substituted with different functional groups, capable of forming hydrogen bonds only, halogen bonds only, both hydrogen and halogen bonds, or nonspecific interactions only with the polymer. Intermolecular interactions were studied and confirmed by X-ray photoelectron spectroscopy and infrared spectroscopy. The release rates of ASDs with different DLs were investigated using surface area normalized dissolution. ASDs with hydrogen bond formation between the drug and polymer had lower LoCs, while compounds that were only able to form halogen bonds or nonspecific interactions with the polymer achieved considerably higher LoCs. This study highlights the impact of different types of drug-polymer interactions on ASD dissolution performance, providing insights into the role of drug and polymer chemical structures on the LoC and ASD performance in general.

Clarithromycin versus furazolidone for naïve Helicobacter pylori infected patients in a high clarithromycin resistance area.

BACKGROUND AND AIM: The increase in antibiotic resistance makes the eradication of Helicobacter pylori more difficult. Considering the limitations of the application of susceptibility-guided therapy, it is important to find an effective empirical regimen. The aim of the study is to compare the efficacy, safety, and cost-effectiveness of clarithromycin-based bismuth-containing quadruple therapy (C-BQT) and furazolidone-based bismuth-containing quadruple therapy (F-BQT) in naïve H. pylori positive patients. METHODS: This was an open-label, randomized controlled, crossover trial. The trial comprised two phases. In C-F group, patients received C-BQT in the first phase; those who were still positive for H. pylori infection after the first phase entered the second phase to receive F-BQT as rescue treatment. In F-C group, patients were treated with F-BQT firstly and rescued with C-BQT. RESULTS: As first-line treatments, the eradication rates of C-BQT and F-BQT were 89.7% (157/175) and 92.0% (161/175) (P = 0.458) in intention-to-treat analysis and 93.4% (156/167) and 95.8% (161/168) (P = 0.327) in per-protocol analysis, respectively. The cumulative eradication rates of the C-F group and the F-C group were both 94.3% in intention-to-treat analysis (P = 1.000). Cost-effectiveness indexes of F-BQT and C-BQT were 0.54 and 1.24 in first-line treatments. Frequencies of adverse events in F-BQT and C-BQT had no differences (36.0% in C-BQT vs 32.6% in F-BQT, P = 0.499). CONCLUSIONS: Furazolidone-based bismuth-containing quadruple therapy should be preferred for its excellent cost-effectiveness and acceptable safety.

Highly Enantiospecific Borylation for Chiral α-Amino Tertiary Boronic Esters.

Herein we report a highly efficient and enantiospecific borylation method to synthesize a wide range of enantiopure (>99 % ee) α-amino tertiary boronic esters. The configurationally stable α-N-Boc substituted tertiary organolithium species and pinacolborane (HBpin) underwent enantiospecific borylation at -78 °C with the formation of a new stereogenic C-B bond. This reaction has a broad scope, enabling the synthesis of various α-amino tertiary boronic esters in excellent yields and, importantly, with universally excellent enantiospecificity (>99 % es) and complete retention of configuration.

Ramosetron for the treatment of irritable bowel syndrome with diarrhea: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Ramosetron is a potent and selective serotonin type 3 receptor antagonist. This meta-analysis aimed to analyze the efficacy and safety of ramosetron for irritable bowel syndrome with diarrhea (IBS-D). METHODS: Pubmed, MEDLINE, EMBASE and the Cochrane Library were searched for randomized controlled trials investigating the efficacy and safety of ramosetron for IBS-D. Risk of bias was assessed as described in the Cochrane handbook. A random effects model was used to calculate the effects of ramosetron vs placebo on symptomatic improvements, including relief of overall IBS symptoms, relief of abdominal discomfort/pain, improvement in abnormal bowel habits, and improvement in stool consistency, expressed as pooled relative risks (RRs) with 95% confidence interval (CI). Adverse events data were also summarized with RRs. RESULTS: Four randomized controlled trials involving 1623 participants were included. Compared with placebo, ramosetron could lead to relief of overall IBS symptoms (RR 1.70; 95%CI 1.48, 1.95), relief of abdominal discomfort/pain (RR 1.41; 95%CI, 1.24, 1.59), improvement in abnormal bowel habits (RR 1.72; 95%CI, 1.50, 1.98) and improvement in stool consistency (RR 1.71; 95%CI 1.40, 2.08). Ramosetron could lead to relief of overall IBS symptoms in both male and female patients (RR; 95%CI: 1.94; 1.58, 2.38 and 1.49; 1.25, 1.79). The RR (95%CI) for reported adverse events of ramosetron vs placebo was 1.10 (0.97, 1.26) across all studies. No serious adverse events (e.g., ischemic colitis) were reported. The incidences of hard stool and constipation were higher in ramosetron group compared with placebo group (RR; 95%CI: 4.74; 3.00, 7.51 and 2.53; 1.57, 4.10, respectively). CONCLUSIONS: Ramosetron had beneficial effects to both male and female IBS-D patients. Treatment with ramosetron could cause more hard stool and constipation, without severe adverse events.