Comparison of Flow and Compression Properties of Four Lactose-Based Co-Processed Excipients: Cellactose® 80, CombiLac®, MicroceLac® 100, and StarLac®

The utilization of co-processed excipients (CPEs) represents a novel approach to the preparation of orally disintegrating tablets by direct compression. Flow, consolidation, and compression properties of four lactose-based CPEs—Cellactose® 80, CombiLac®, MicroceLac® 100, and StarLac®—were investigated using different methods, including granulometry, powder rheometry, and tablet compaction under three pressures. Due to the similar composition and the same preparation technique (spray drying), the properties of CPEs and their compacts were generally comparable. The most pronounced differences were observed in flowability, undissolved fraction after 3 min and 24 h, energy of plastic deformation (E2), ejection force, consolidation behavior, and compact friability. Cellactose® 80 exhibited the most pronounced consolidation behavior, the lowest values of ejection force, and high friability of compacts. CombiLac® showed excellent flow properties but insufficient friability, except for compacts prepared at the highest compression pressure (182 MPa). MicroceLac® 100 displayed the poorest flow properties, lower ejection forces, and the best mechanical resistance of compacts. StarLac® showed excellent flow properties, the lowest amounts of undissolved fraction, the highest ejection force values, and the worst compact mechanical resistance. The obtained results revealed that higher compression pressures need to be used or further excipients have to be added to all tested materials in order to improve the friability and tensile strength of formed tablets, except for MicroceLac® 100.

Influence of External Factors on Airborne Missile’s Horizontal Backward Launching

This paper studies the influence of different external disturbance factors on the horizontal backward separation of airborne missiles on large transport aircraft. The method of comparison with experiment was adopted to verify the accuracy of the finite element model during the ejection process. By comparing the finite element model, it was confirmed that the all rigid body model and partly rigid body model are inaccurate in calculating the pitch angle and pitch velocity of the missile separation. Finally, the influences of ejection force, random vibration, and missile loading position on the ejection process are analyzed. The analysis found that the ejection force and the sliding distance will increase the vibration of the launching platform, therefore increase the separation pitch angle and the pitch velocity of the missile, but the influence of random vibration on platform is much greater than the other two factors, and it will also introduce randomness into the movement of the missile.

Clinical Study on Long-Term Sinus Reversion Rate and Left Atrial Function Recovery of Mitral Valve Disease with Atrial Fibrillation under Modified Surgical Radiofrequency Ablation

We aimed to study the long-term sinus reversion rate and recovery of left atrial function after modified surgical radiofrequency ablation for permanent atrial fibrillation caused by mitral valve disease. From March 2014 to May 2020, 35 patients who underwent modified surgical radiofrequency ablation during cardiac valve surgery in our hospital were selected as the study group, and 25 normal individuals without cardiac structural changes were selected as the control group. The time of modified surgical radiofrequency ablation and long-term sinus reversion rate were measured, and left atrial anteroposterior, superoinferior, left and right diameters, left atrial ejection fraction, left atrial filling index, and left atrial ejection force were measured before and 6 months after surgery. The mean ablation time was 23.2 min, and the long-term sinus reversion rate was 80.0%. The left atrium diameter decreased and the left atrium ejection fraction increased after the operation ( P < 0.05 ). The left atrium filling index and ejection force were significantly increased in 28 patients with sinus reversion ( P < 0.05 ). The decrease in left atrial diameter and the increase in left atrial ejection fraction were correlated with sinus conversion after surgery ( P < 0.05 ). The modified operation is simple, the curative effect is definite, and the sinus reversion rate is high, which is beneficial to the restoration of left atrial structure, ejection function, and hemodynamic function.

Performance Evaluation of a Novel Biosourced Co-Processed Excipient in Direct Compression and Drug Release

This study exposes the potential usefulness of a new co-processed excipient, composed of alginic acid and microcrystalline cellulose (Cop AA-MCC), for the preparation of immediate drug release tablets by direct compression. Evaluation of the physical and mechanical properties as well as the disintegration behavior of Cop AA-MCC in comparison to commercial co-processed excipients (Cellactose®, Ludipress®, Prosolv® SMCC HD90 and Prosolv® ODT) and to the physical mixture of the native excipients (MCC and AA), was carried out. The obtained results illustrate the good performance of Cop AA-MCC in terms of powder flowability, tablet tensile strength, compressibility, and disintegration time. Although, this new co-processed excipient showed a slightly high lubricant sensitivity, which was explained by its more plastic than fragmentary deformation behavior, it presented a low lubricant requirement due to the remarkably low ejection force observed during compression. Compression speed and dwell time seemed not to affect significantly the tabletability of Cop AA-MCC. The study exposed evenly the performance of Cop AA-MCC compared to Prosolv® ODT, in terms of tabletability and dissolution rate of Melatonin. Cop AA-MCC presented comparable hardness, lower dilution potential, higher lubricant sensitivity, lower ejection force, and faster Melatonin’s release time than Prosolv® ODT. In summary, Cop AA-MCC exhibited interesting physical, mechanical, and biopharmaceutical properties, which demonstrate its concurrence to commercially available co-processed excipients. Furthermore, the simplicity of its composition and the scalability of its elaboration makes this multifunctional excipient highly recommended for direct compression.

Metallurgical Soldering of Duplex CrN Coating in Contact with Aluminum Alloy

Coatings deposited by physical vapor deposition (PVD) significantly reduce the wear of high pressure die casting tools; however, cast alloy soldering still has a strong negative effect on production efficiency. Although a lot of research has been already done in this field, the fundamental understanding of aluminum alloy soldering toward PVD coatings is still scarce. Therefore, in this work the performance of CrN duplex coatings with different roughness is evaluated by a modified ejection test performed with delayed (DS) and conventional casting solidification (CS). After the ejection tests, sample surfaces and layers were subjected to comprehensive characterizations of their morphological and chemical characteristics. Considerably lower values of the ejection force were recorded in DS experiments than in CS experiments. Surface roughness played an important role in the CS experiments, while samples with different surface topographies in the DS experiments performed in a similar fashion. The decrease in the ejection force, observed in DS tests, is attributed to the formation of a thick Cr–O layer on CrN coating which reduced soldering and sliding friction against thick Al–O casting scale. The Cr–O layer formed in DS experiments suffered from diffusion wear by cast alloy. The observed oxidation phenomena of nitride coatings may be utilized in a design of non-sticking coatings.

Vasomotor Center? A Possible Role in the Treatment of Hypertension

The global burden of hypertension and associated co-morbidities (cardiac failure, renal failure), is constantly rising despite the availability of newer drugs. Therefore, this study was planned to review the role of VMC (Vasomotor Center) in hypertension along with adding stress-relieving methods in lifestyle measures to prevent an epidemic of hypertension. For this purpose textbook of physiology, and various reference studies were used. The text-book of physiology suggests the location of VMC (Lower pons and medulla) and its functioning related to blood pressure regulation. It receives a signal from baroreceptors and produces either a decrease or an increase in blood pressure. The VMC is influenced by the cerebral cortex and hypothalamus. The pathophysiology suggests that possibly chronic stress, mental overwork disturbs the cortical influences to hypothalamus and shifts VMC to a higher level and that results in high basal sympathetic discharge and increased LV ejection force along with shifting of baroreceptors and renal mechanism to a new higher level which brings the blood pressure or whole body vasculature to the same high level resulting in hypertension. The repetition of the same process shifts BP even higher. The centrally acting drugs, mental rest, sound sleep and stress relieving methods like yoga, Vipassana, etc. may help to reduce cortical impulses and to bring VMC back to normal. VMC will automatically correct various BP control mechanisms and bring back BP to normal. Thus continuous efforts are needed to remove precipitating factors of hypertension. The methods to relieve stress and exhaustion must be employed in lifestyle for hypertension besides JNC guidelines.

P2598Left atrial mechanics in patients with acute pulmonary edema and preserved ejection fraction

Background The left atrium (LA) is a highly dynamic chamber that has 3 mechanical functions (reservoir, conduit, booster pump), as well as additional endocrine and regulatory properties. It is a marker of both the severity and chronicity of diastolic dysfunction and its remodelling has been shown to be a reliable predictor of clinical outcome in patients with heart disease. While LA function has been extensively studied in chronic heart failure, information about LA mechanics in patients with acute heart failure and preserved left ventricular ejection fraction (EF) are scarce. Purpose We sought to assess LA mechanics in a cohort of patients with acute pulmonary edema and preserved EF and compare it with a normal reference group. Methods We included 50 consecutive patients (22 men) with acute pulmonary edema, preserved EF and sinus rhythm in our study. Patients with significant mitral or aortic valve disease were not considered eligible. The control group consisted of 30 subjects (18 men) with no previous cardiovascular disease. We performed conventional transthoracic echocardiography for all patients and we assessed various parameters of LA mechanics. To evaluate the reservoir function, we determined the total ejection volume (EV), the total EF, the LA expansion index (LAEI) and the LA function index (LAFI). To evaluate the conduit function, we determined the passive EV and passive EF. For the booster pump function, we determined the active EV, active EF, the atrial filling fraction, the ejection force and the LA kinetic energy (LAKE). We used T-test to compare the parameters between the two groups. Results The mean age in the study group was 72±14 years, while in the control group the mean age was 56±16 years (p=0.06). The total EV did not differ significantly between groups (p=0.44). The total LA ejection fraction was lower in the study group: 29±10% vs. 51±9% (p<0.001), as well as the LAEI (45.1±24.6 vs. 110.9±32.1, p<0.001) and the LAFI (0.17±0.12 vs. 0.58±0.20, p<0.001). Among parameters assessing LA conduit function, there were no differences in passive EV (p=0.64), but passive LA ejection fraction was significantly lower in the study group: 15±7% vs. 28±11%, p=0.003. The same trend was noted for active LA ejection fraction (16±10% vs. 31±13%, p=0.005). The ejection force was impaired in the study group: 39.1±30.6 kdynes vs. 15.2±12.3 kdynes, p<0.001. Other parameters evaluating LA booster pump function did not differ significantly between groups (p=0.12 for atrial filling fraction, p=0.74 for LAKE). Conclusion All three integrated phases of left atrial mechanics (reservoir, conduit, booster pump) are impaired in patients with acute pulmonary edema and preserved left ventricular EF. These findings highlight the importance of diastolic dysfunction in the pathogenesis of acute heart failure for these patients and they suggest that LA dysfunction might be a potential therapeutic target in this clinical setting. Acknowledgement/Funding This work was supported by CREDO Project - ID: 49182, financed through the SOP IEC-A2-0.2.2.1-2013-1 cofinanced by the ERDF

Development and Evaluation of an Injectable Chitosan/β-Glycerophosphate Paste as a Local Antibiotic Delivery System for Trauma Care

Complex open musculoskeletal wounds are a leading cause of morbidity worldwide, partially due to a high risk of bacterial contamination. Local delivery systems may be used as adjunctive therapies to prevent infection, but they may be nondegradable, possess inadequate wound coverage, or migrate from the wound site. To address this issue, a thermo-responsive, injectable chitosan paste was fabricated by incorporating beta-glycerophosphate. The efficacy of thermo-paste as an adjunctive infection prevention tool was evaluated in terms of cytocompatibility, degradation, antibacterial, injectability, and inflammation properties. In vitro studies demonstrated thermo-paste may be loaded with amikacin and vancomycin and release inhibitory levels for at least 3 days. Further, approximately 60% of thermo-paste was enzymatically degraded within 7 days in vitro. The viability of cells exposed to thermo-paste exceeded ISO 10993-5 standards with approximately 73% relative viability of a control chitosan sponge. The ejection force of thermo-paste, approximately 20 N, was lower than previously studied paste formulations and within relevant clinical ejection force ranges. An in vivo murine biocompatibility study demonstrated that thermo-paste induced minimal inflammation after implantation for 7 days, similar to previously developed chitosan pastes. Results from these preliminary preclinical studies indicate that thermo-paste shows promise for further development as an antibiotic delivery system for infection prevention.