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Brake friction material reinforced with coconut fiber and dypsis lutescens fiber was designed and prepared in this study. Specimens incorporating 0-8 wt.% of coconut fibers or dypsis lutescens fibers were fabricated. The effect of the content of these reinforcing fibers on the overall properties of brake friction materials was systematically investigated. The results indicate that the inclusion of reinforcing fibers in the formulation of brake friction materials can improve the physical properties and friction and wear properties of brake friction materials. The specimen incorporating 6 wt.% plant fiber obtained the optimal comprehensive performance with excellent fade resistance and recovery properties, and better wear resistance. In order to further investigate their performance, nine hybrid fiber brake friction materials were designed using the golden section method and orthogonal test method. The study indicated that the F-6 hybrid fiber-reinforced brake friction materials have better physical properties, thermal degradation resistance, recovery properties, and abrasion resistance than the single-fiber-reinforced brake friction materials. This study provides new concepts for the preparation of fiber-reinforced brake friction materials as well as formulation optimization.

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Binder selection is a crucial step in continuous twin-screw wet granulation (TSWG), as the material experiences a much shorter residence time (2-40 s) in the granulator barrel compared to batch-wise granulation processes. Polyvinyl alcohol (PVA) 4-88 was identified as an effective binder during TSWG, but the potential of other PVA grades-differing in polymerization and hydrolysis degree-has not yet been studied. Therefore, the aim of the current study was to evaluate the potential of different PVA grades as a binder during TSWG. The breakage and drying behavior during the fluidized bed drying of drug-loaded granules containing the PVA grades was also studied. Three PVA grades (4-88, 18-88, and 40-88) were characterized and their attributes were compared to previously investigated binders by Vandevivere et al. through principal component analysis. Three binder clusters could be distinguished according to their attributes, whereby each cluster contained a PVA grade and a previously investigated binder. PVA 4-88 was the most effective binder of the PVA grades for both a good water-soluble and water-insoluble formulation. This could be attributed to its high total surface energy, low viscosity, good wettability of hydrophilic and hydrophobic surfaces, and good wettability by water of the binder. Compared to the previously investigated binders, all PVA grades were more effective in the water-insoluble formulation, as they yielded strong granules (friability below 30%) at lower L/S-ratios. This was linked to the high dispersive surface energy of the high-energy sites on the surface of PVA grades and their low surface tension. During fluidized bed drying, PVA grades proved suitable binders, as the acetaminophen (APAP) granules were dried within a short time due to the low L/S-ratio, at which high-quality granules could be produced. In addition, no attrition occurred, and strong tablets were obtained. Based on this study, PVA could be the preferred binder during twin screw granulation due to its high binder effectiveness at a low L/S-ratio, allowing efficient downstream processing. However, process robustness must be controlled by the included excipients, as PVA grades are operating in a narrow L/S-ratio range.

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OBJECTIVES: To prepare 7-hydroxyethyl chrysin (7-HEC) loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles and to detect the in vitro release. METHODS: The 7-HEC/PLGA nanoparticles were prepared by emulsification solvent volatilization method. The particle size, polydispersity index (PDI), encapsulation rate, drug loading and zeta potential were measured. The prescription was optimized by single factor investigation combined with Box-Behnken response surface method. Mannitol was used as protectant to prepare lyophilized powder, and the optimal formulation was characterized and studied for the in vitro release. RESULTS: The optimal formulation of 7-HEC/PLGA nanoparticles was as follows: drug loading ratio of 2.12∶20, oil-water volume ratio of 1∶14.7, and 2.72% soybean phospholipid as emulsifier. With the optimal formulation, the average particle size of 7-HEC/PLGA nanoparticles was (240.28±0.96) nm, the PDI was 0.25±0.69, the encapsulation rate was (75.74±0.80)%, the drug loading capacity was (6.98±0.83)%, and the potentiostatic potential was (－18.17±0.17) mV. The cumulative in vitro release reached more than 50% within 48 h. CONCLUSIONS: The optimized formulation is stable and easy to operate. The prepared 7-HEC/PLGA nanoparticles have uniform particle size, high encapsulation rate and significantly higher dissolution rate than 7-HEC.

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In the context of the "antibiotic ban" era, the feed conversion of medicinal and edible traditional Chinese medicine(TCM) resources is a research hotspot in the field of antibiotic alternatives development. How to develop feed products that are beneficial to agriculture and livestock while ensuring nutrient balance and precision using medicinal and edible TCM resources as raw materials has become a challenge. Artificial intelligence(AI) technology has unique advantages in feed production and improving the efficiency of intelligent breeding. If AI technology is applied to the feed development of medicinal and edible TCM resources, it is possible to realize feeding and antibiotic-replacement value while ensuring precise nutrition. In order to better apply AI technology in the field of feed development of medicinal and edible TCM resources, this article used CiteSpace software to carry out literature visualization analysis and found that AI technology had a good application in the field of feed formulation optimization in recent years. However, there is still a gap in the research on the intelligent utilization of medicinal and edible TCM resources. Nonetheless, it is feasible for AI technology to be applied to the feed conversion of medicinal and edible TCM resources. Therefore, this article proposed for the first time an intelligent formulation system framework for feed materials derived from medicinal and edible TCM resources to provide new ideas for research in the field of feed development of medicinal and edible TCM resources and the research on the development of antibiotic alternatives. At the same time, it can pave the way for a new green industry chain for contemporary animal husbandry and the TCM industry.

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This study outlines a practical approach for assessing chemical instability by heating the drug-excipient binary mixtures or multi-excipient formulations at 75°C for 3 days before characterization. Differentiating itself from other excipient compatibility methods, our methodology necessitates a saturated aqueous slurry rather than arbitrarily fixed water content. This allows bulk and surface water in the excipient to contribute to drug degradation. The synergistic impact of surface water and elevated temperature expedites degradation kinetics, resulting in accelerated data generation. Among excipient compatibility methods available, our method is quantitative and merges with traditionally used methodologies. The devised nomograph enables extrapolation of shelf life at 20°C from experimental data obtained at 75°C. This methodology also helped identify stabilizers for the drug NVS-1 where traditional excipient compatibility programs had failed. Incorporation of monovalent salts, such as sodium/potassium chloride and sodium bicarbonate at 5% w/w, significantly enhanced the chemical stability of NVS-1, ensuring stable tablet formulations. Our hypothesis posits that stabilization is due to increased ionic strength in the slurry, which stabilizes an induced dipole within the polar NVS-1 drug. Additionally, the presence of ions in the moisture layer is anticipated to stabilize π-π stacking of two planar aromatic NVS-1 molecules. The expedited generation of experimental data allowed the identification of inorganic salts to supplement a standard excipient compatibility screening panel. Considering the economic implications of stability testing methodologies in effort, cost, and duration, a faster turnaround in chemical stability data enhances formulation selection. This ultimately facilitates the development of drug formulations with greater efficiency without delays.

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Magnetic resonance imaging contrast agents are frequently used in clinics to enhance the contrast between diseased and normal tissues. The previously reported poly(acrylic acid) stabilized exceedingly small gadolinium oxide nanoparticles (ES-GdON-PAA) overcame the problems of commercial Gd chelates, but limitations still exist, i.e., high r2/r1 ratio, long blood circulation half-life, and no data for large scale synthesis and formulation optimization. In this study, polymaleic acid (PMA) is found to be an ideal stabilizer to synthesize ES-GdONs. Compared with ES-GdON-PAA, the PMA-stabilized ES-GdON (ES-GdON-PMA) has a lower r2/r1 ratio (2.05, 7.0 T) and a lower blood circulation half-life (37.51 min). The optimized ES-GdON-PMA-9 has an exceedingly small particle size (2.1 nm), excellent water dispersibility, and stability. A facile, efficient, and environmental friendly synthetic method is developed for large-scale synthesis of the ES-GdONs-PMA. The weight of the optimized freeze-dried ES-GdON-PMA-26 synthesized in a 20 L of reactor reaches the kilogram level. The formulation optimization is also finished, and the concentrated ES-GdON-PMA-26 formulation (CGd = 100 mm) after high-pressure steam sterilization possesses eligible physicochemical properties (i.e., pH value, osmolality, viscosity, and density) for investigational new drug application.

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OBJECTIVE To prepare the Eriodictyol chewable tablet and to evaluate its quality. METHODS The chewable tablet was prepared by the wetting granulation method by using microcrystalline cellulose （MCC） and mannitol as fillers， polyvinylpyrrolidone （PVP） as adhesive， citric acid and sucralose as flavor correction agents， magnesium stearate as lubricant. The comprehensive evaluation was conducted on Eriodictyol chewable tablets with the dosage of each excipient as a factor using the appearance， taste， flavor and texture as indicators. The ratio of excipients was optimized by orthogonal test， and the quality of Eriodictyol chewable tablets prepared by optimized formulation was evaluated in terms of appearance， weight difference， hardness， fragility， eriodictyol content， dissolution and content uniformity. RESULTS The optimal formulation was as follows： 26.4% eriodictyol （50 mg each piece）， 45% mannitol， 25% MCC， 0.3% citric acid， 0.3% sucralose， 1% magnesium stearate， 2% PVP （preparing 5% solution using purified water）. The scores of 3 batches of Eriodictyol chewable tablets in the validation test were 8.76， 8.75 and 8.80 （RSD＝0.30%， n＝3）， respectively. The Eriodictyol chewable tablet had a complete appearance and a smooth surface； the average tablet weight was 192.57 mg， the average hardness was 57.36 N， the fragility was 0.09%， the average content of eriodictyol per tablet was 50.74 mg， the cumulative dissolution within 30 min was exceeding 80%， and the content uniformity was 5.51. CONCLUSIONS Eriodictyol chewable tablet prepared by optimal formulation conforms to the requirements of the 2020 edition of Chinese Pharmacopoeia.

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Artificial Intelligence (AI) has emerged as a powerful tool in various domains, and the field of drug formulation and development is no exception. This review article aims to provide an overview of the applications of AI in drug formulation and development and explore its future prospects. The article begins by introducing the fundamental concepts of AI, including machine learning, deep learning, and artificial neural networks and their relevance in the pharmaceutical industry. Furthermore, the article discusses the network and tools of AI and its applications in the pharmaceutical development process, including various areas, such as drug discovery, manufacturing, quality control, clinical trial management, and drug delivery. The utilization of AI in various conventional as well as modified dosage forms has been compiled. It also highlights the challenges and limitations associated with the implementation of AI in this field, including data availability, model interpretability, and regulatory considerations. Finally, the article presents the future prospects of AI in drug formulation and development, emphasizing the potential for personalized medicine, precision drug targeting, and rapid formulation optimization. It also discusses the ethical implications of AI in this context, including issues of privacy, bias, and accountability.

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Oral delivery of peptides and biological molecules promises significant benefits to patients as an alternative to daily injections, but the development of these formulations is challenging due to their low bioavailability and high pharmacokinetic variability. Our earlier work focused on the discovery of MEDI7219, a stabilized, lipidated, glucagon-like peptide 1 agonist peptide, and the selection of sodium chenodeoxycholate (Na CDC) and propyl gallate (PG) as permeation enhancer combinations. We hereby describe the development of the MEDI7219 tablet formulations and composition optimization via in vivo studies in dogs. We designed the MEDI7219 immediate-release tablets with the permeation enhancers Na CDC and PG. Immediate-release tablets were coated with an enteric coating that dissolves at pH ≥ 5.5 to target the upper duodenal region of the gastrointestinal tract and sustained-release tablets with a Carbopol bioadhesive polymer were coated with an enteric coating that dissolves at pH ≥ 7.0 to provide a longer presence at the absorption site in the gastrointestinal tract. In addition to immediate- and enteric-coated formulations, we also tested a proprietary delayed release erodible barrier layer tablet (OralogiKTM) to deliver the payload to the target site in the gastrointestinal tract. The design of tablet dosage forms based on the optimization of formulations resulted in up to 10.1% absolute oral bioavailability in dogs with variability as low as 26% for MEDI7219, paving the way for its clinical development.

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In order to develop environment friendly microbial inhibitor that can also control disease and promote oat (Avena sativa) growth, the growth rate method and response surface methodology were used to screen wetting agents, preservatives and protective agents at optimal concentrations in this study. Antagonistic activity of the tested bacterium and cell-free fermentation liquid against pathogenic fungi was evaluated on potato dextrose agar (PDA) substratum plates by dual culture technique. Oxford cup method was used to measure antagonistic reaction between screened bacteria. According to each screened bacteria with 50 mL were mixed and cultured in Luria-bertani (LB) substratum. Additives of Wetting agents, UV-protectors, and preservatives were screened by single factor test on the growth concentration of screened mixed bacteria. Afterwards, the optimal additives and concentrations were screened by Box-Behnken method. The microbial inhibitor was detected according to national standards GB20287-2006 and tested on oat in a pot experiment. The results showed that: (1) Functional bacteria which including Bacillus velezensis and Brevundimonas faecalis had control effects of 50.00% to 83.29% on three pathogenic fungi, and their cell free-fermentation liquid could inhibit the growth of pathogenic fungi from 23.51% to 39.90%; (2) Tween-80 was most suitable as wetting agents for Mix biocontrol bacteria (MBB) with 1.00% mass fraction; Sorbitol was selected as UV protective agents for MBB with 0.50% mass fraction. And methyl paraben was used as a preservative for MBB, with 0.50% mass fraction; (3) The most effective adjuvant contained 14.96 mL/L Tween-80, 5.12 g/L methylparaben and 5.6 g/L sorbitol; and (4) The microbial inhibitor controlled 45.57% of oat root rot and increased plant height, root length and seedling biomass. This study provides a suitable environment for the protection of mixed biocontrol bacteria, and lays a foundation for the prevention and control of oat diseases, the promotion of growth and the improvement of quality.

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This technical note investigated the loss of dissolution rate during accelerated stability studies with a dry blend capsule formulation containing an amorphous salt of drug NVS-1 (Tg 76°C). After 6 m at 40°C/75%RH, dissolution of NVS-1 was ≤40% of initial value. Scanning electron microscope characterization of the undissolved capsule contents from samples stored at 50°C/75%RH for 3 weeks showed agglomeration with a distinct "melt and fuse" morphology of particles. At elevated temperature and humidity conditions, undesired sintering among the amorphous drug particles was observed. Humidity plasticizes the drug as the stability temperature (T) gets closer to the glass transition temperature (Tg) of the amorphous salt (i.e., smaller Tg-T); a decreased viscosity favors viscoplastic deformation and sintering of drug particles. When moisture is adsorbed onto agglomerated drug particles, partial dissolution of the drug forms a viscous surface layer, further reducing the rate of dissolution media penetration into the bulk solid, hence the slower dissolution rate. Formulation intervention focused on the use of L-HPC and fumed silica as disintegrant and glidant and the removal of the hygroscopic crospovidone. Reformulation improved dissolution performance at short-term accelerated stability conditions of 50°C (± 75%RH); however, sintering to a lesser extent was still observed at high humidity, impacting the dissolution rate. We infer reducing the impact of moisture at high humidity conditions in a formulation with a 34% drug load is challenging. Future formulation efforts will focus on the addition of water scavengers, reducing drug load by ~50% to physically separate drug particles by water-insoluble excipients, and optimizing disintegrant levels.

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Tetrazolium salts provide an appealing candidate for 3D gel dosimeters as they exhibit a low intrinsic color, no signal diffusion and excellent chemical stability. However, a previously developed commercial product (the ClearView 3D Dosimeter) based on a tetrazolium salt dispersed within a gellan gum matrix presented a noticeable dose rate effect. The goal of this study was to find out whether ClearView could be reformulated in order to minimize the dose rate effect by optimizing of the tetrazolium salt and gellan gum concentrations and by the addition a thickening agent, ionic crosslinkers, and radical scavengers. To that goal, a multifactorial design of experiments (DOE) was conducted in small-volume samples (4-mL cuvettes). It showed that the dose rate could be effectively minimized without sacrificing the integrity, chemical stability, or dose sensitivity of the dosimeter. The results from the DOE were used to prepare candidate formulations for larger-scale testing in 1-L samples to allow for fine-tuning the dosimeter formulation and conducting more detailed studies. Finally, an optimized formulation was scaled-up to a clinically relevant volume of 2.7 L and tested against a simulated arc treatment delivery with three spherical targets (diameter 3.0 cm), requiring different doses and dose rates. The results showed excellent geometric and dosimetric registration, with a gamma passing rate (at 10% minimum dose threshold) of 99.3% for dose difference and distance to agreement criteria of 3%/2 mm, compared to 95.7% in the previous formulation. This difference may be of clinical importance, as the new formulation may allow the quality assurance of complex treatment plans, relying on a variety of doses and dose rates; thus, expanding the potential practical application of the dosimeter.

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Dissolving microneedles (MNs) have emerged as a promising transdermal delivery system, as they integrate the advantages of both injection and transdermal preparations. However, the low drug-loading and limited transdermal delivery efficiency of MNs severely hinder their clinical applications. Microparticle-embedded gas-propelled MNs were developed to simultaneously improve drug-loading and transdermal delivery efficiency. The effects of mold production technologies, micromolding technologies, and formulation parameters on the quality of gas-propelled MNs were systematically studied. Three-dimensional printing technology was found to prepare male mold with the highest accuracy, while female mold made from the silica gel with smaller Shore hardness could obtain a higher demolding needle percentage (DNP). Vacuum micromolding with optimized pressure was superior to centrifugation micromolding in preparing gas-propelled MNs with significantly improved DNP and morphology. Moreover, the gas-propelled MNs could achieve the highest DNP and intact needles by selecting polyvinylpyrrolidone K30 (PVP K30), polyvinyl alcohol (PVA), and potassium carbonate (K2CO3): citric acid (CA) = 0.15:0.15 (w/w) as the needle skeleton material, drug particle carrier, and pneumatic initiators, respectively. Moreover, the gas-propelled MNs showed a 1.35-fold drug loading of the free drug-loaded MNs and 1.19-fold cumulative transdermal permeability of the passive MNs. Therefore, this study provides detailed guidance for preparing MNs with high productivity, drug loading, and delivery efficiency.

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Polyphyllin I (PPI), an effective active ingredient in Paris polyphylla, has a diverse set of pharmacological properties. However, due to its poor solubility and oral absorption, its application and development are limited. In the study, we were committed to improving the solubility of PPI by developing a self-microemulsifying drug delivery system of PPI (PPI-SMEDDS), screening the best preparation process, and evaluating the quality and the in vivo pharmacokinetics of PPI, and PPI-SMEDDS following oral administration to rats were also studied. In addition, the pharmacological activities against human lung adenocarcinoma cell A549 in vitro were assessed. The best formulation had 15.89% ethyl oleate, 47.38% Cremophor RH40, and 36.73% 1,2 propylene glycol. The produced PPI-SMEDDS was clear and transparent, with an average particle size of 24.51 nm and a zeta potential of -17.54 ± 0.51 mV. In vitro, the cumulative release rate of PPI-SMEDDS was nearly 80% within 2 h. PPI-SMEDDS had a substantially greater area under the curve than PPI following oral treatment in rats, and the relative bioavailability of PPI in rats was 278.99%. More importantly, the anti-tumor effect of PPI-SMEDDS in vitro was significantly greater than that of PPI. These findings suggested that PPI-SMEDDS has the potential to improve the solubility, oral bioavailability of PPI, and anti-tumor effect, laying the groundwork for future research on the new PPI dosage form.

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Objective Screening of modified Foshou San to improve cerebral ischemia,determine the best prescription composition and the proper dose.Methods Using data mining method,the traditional Chinese medicine for hypertensive intracerebral hemorrhage(HICH)were screened,and cluster analysis was carried out to obtain Jiawei Foshou San combinations;According to the mixed uniform design U14(42×33×22),the auricular artery dilatation experiment and acute cerebral ischemia induced by saturated magnesium chloride in mice were used to observe the auricular artery dilatation index and survival time of mice,and the pharmacological effects of each prescription to improve cerebral ischemia were evaluated.On the basis of visual analysis of pharmacodynamics,stepwise multiple regression analysis was carried out,and the regression equation was used to calculate the best prescription composition and dose of Jiawei Foshou San.The optimized prescription was verified by acute cerebral ischemia experiment in mice.Results A total of 51 prescriptions that may be used for the treatment of HICH were selected by data mining,including 103 Chinese herbs,with a total frequency of 535 times.The results of mixed uniform design U14(42×33×22)test showed that the auricular artery index of mice in each prescription group of Jiawei Foshou San increased to varying degrees.The differences between prescription 4,8,12 and 13 were significant(P<0.05),and the differences between prescription 3,7,9,11 and 14 were extremely significant(P<0.01).The survival time of acute cerebral ischemia in mice was prolonged to varying degrees in each group of Jiawei Foshou San,and the difference between prescription 2-14 groups and the blank group was statistically significant(P<0.01).The prescription of the new Jiawei Foshou San was determined as 60 g of Astragalus membranaceus,60 g of Angelica sinensis,24 g of Ligusticum chuanxiong,15 g of Paeonia lactiflora and 9 g of Dilong from the intuitive analysis.The validation results showed that the high and middle dosage of the new Jiawei Foshou San could significantly prolong the breathing time,increase the number of breaths,and prolong the time of normal pressure hypoxia tolerance in mice with acute cerebral ischemia(P<0.01,P<0.05).Conclusion Using mixed uniform design combined with improving cerebral ischemia effect index can determine the best prescription composition and the best dose of Jiawei Foshou San,and the effect of improving cerebral ischemia is certain.

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OBJECTIVE To optimize the formulation of a porcine fibrin patch （abbreviated as “DBT”）. METHODS Based on single-factor tests， with the contents of fibrinogen， thrombin and collagen before freeze-drying as the factors， with the overall desirability （OD） value of adhesion strength， holding viscosity and water absorption as response value， the formulation of DBT was optimized by Box-Behnken-response surface methodology， and the verification tests were conducted. RESULTS According to the results of the single factor tests and Box-Behnken-response surface methodology， combined with the actual production， the optimal formulation of DBT was 6.5 mg/cm2 of fibrinogen， 8.0 IU/cm2 of thrombin and 5.6 mg/mL of collagen. The average OD value of 3 validation tests was 0.726 6 （RSD＝0.58%， n＝3）， and the relative error of which with the predicted value （0.733 0） was －0.87%. CONCLUSIONS The optimal formulation of DBT is stable and feasible.

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Licorzine granules are common preparations for children zinc deficiency. Considering the long course of treatment, the taste of licorzine granules may become a main factor affecting medication adherence. To date there have been no taste evaluation research into licorzine granules yet. In this study, both sensory evaluation and electronic tongue method were utilized to optimize licorzine granules formulations, evaluate the tastes of licorzine, excipients, optimized formulation in vivo and in vitro. As the results show, bitterness and astringency are the main unpleasant tastes generating from licorzine. Xanthan gum is the main taste-masking excipient, lowering down the bitterness and astringency of licorzine by at least one grade. Good correlation exists between the results of sensory evaluation and electronic tongue method, and an integrated combination of the two helps to obtain objective and rational research conclusions. The adult sensory evaluation study was a research-based clinical trial conducted with informed consent from all subjects in accordance with the ethical requirements of Good Clinical Practice.

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The growing interest in high-energy emulsification is a result of its scalability, which is important from an industrial perspective and allows for a more reproducible and efficient production of pharmaceutical formulations. The aim of this study was to evaluate the effect of composition, mainly a fixed surfactant/cosurfactant (Smix) ratio, their concentration, and the parameters of high-pressure homogenization (HPH) processing on the quality and stability of ophthalmic fluconazole-loaded nanoemulsions. After a physicochemical analysis of nanoemulsions containing 20% w/w of oil, as optimal conditions for the HPH process, three cycles at a pressure of 1000 bar were established, obtaining formulations with an average droplet diameter size in the range of 80.63-129.68 nm and PDI values below 0.25. While it was expected that an increasing cosurfactant concentration decreased the droplet size, in the case of formulations containing Tween 20 and 10% w/w of cosurfactants, "over-processing" was observed, identified by the droplet size and polydispersity index increase. Consecutively, the selected formulations were evaluated for in vitro drug release in Franz's cell, antifungal activity, and 30-day stability using NMR spectroscopy. An antifungal activity test showed no significant difference in the antifungal activity between optimal fluconazole-loaded nanoemulsions and a 0.3% aqueous drug solution, but previously, research showed that prepared formulations were characterized by a higher viscosity and satisfactory prolonged release compared to a control. In a 30-day stability study, it was observed that higher HLB values of the used surfactants decreased the stability of the formulations in the following order: Kolliphor EL, Tween 80, Tween 20. The NMR spectra confirmed that Kolliphor EL-based formulations ensured the higher stability of the nanoemulsion composition in comparison to Tween 80 and a better stabilizing effect of propylene glycol as a cosurfactant in comparison to PEG 200. Therefore, the optimization of HPH technology should be focused on the selection of Smix and the Smix:oil ratio in order to prepare stable formulations of high quality.

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Self-healing materials, especially self-healing polyurea/polyurethane, to replace traditional coating has been of increasing interest in the past decade. The frequency of regular maintenance work can also be reduced as the coating is capable of forming bonds at ruptured sites. This reduces the cost of maintenance and the risk involved in workers engaging in maintenance work. The extremely short curing time of polyurea coating could potentially outweigh the cost due to its short down time. With a high self-healing efficiency, self-healing polyurea could be the ultimate choice of protective coating. This report aims to find the optimum formulation for fabrication of polyurea with a high self-healing efficiency. This is conducted by changing the composition of the components chosen for formulation of polyurea. The choice of isocyanate and amine is varied to explore its impact on chain mobility and microphase separation, which are important factors affecting self-healing efficiency. A series of characterizations, including ATR-FTIR, DSC, optical microscope and mechanical tester, is used to analyze the factors affecting the self-healing efficiency of fabricated polyurea and to eventually determine the best formulation. The ideal formulation of toluene 2,4 diisocyanate-amine (TDI-P1000) polyurea managed to achieve a self-healing of 42%. Further studies could be done to include multiple healing mechanisms after different area of polyurea to boost its self-healing efficiency after repeated healing.

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In the context of increasing application of modelling methods in the field of pharmaceutics, this study aims to reduce the weight of sildenafil orally disintegrating tablets (ODTs) and optimize their formulation through modelling methods. To achieve the goal, the back-propagation neural network (BPNN)-based non-dominated sorting genetic algorithm II (NSGA-II) was introduced to establish the models and to optimize the percentage of magnesium stearate (MgSt), crospovidone (PVPP), and croscarmellose sodium (CCNa) to obtain satisfactory candidate ODTs. Ultimately, the bioequivalence trial was conducted to verify the effectiveness of the formulation. With the support of the neural network, the model showed satisfactory results in the prediction of hardness and disintegration time of ODTs, and the pareto front obtained by the NSGA-II suggested that there was a strong "competition" between disintegration time and hardness. Since disintegration time should be given the priority, the optimal formulation was determined as 1% MgSt, 6% CCNa, and 2.6% PVPP. The bioequivalence trial results indicated a bioequivalence between the test and the reference formulations of sildenafil, and better medication experience for the test formulation. A bioequivalent formulation with better medication experience is successfully prepared using the NSGA-II. It proves that the NSGA-II is applicable to multi-objective optimization of the drug formulation.

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