Slow-Release Delivery System for Herbicides in Container-Grown Stock

1993 ◽  
Vol 7 (4) ◽  
pp. 894-899 ◽  
Author(s):  
Stanley F. Gorski
Keyword(s):  
Delivery System ◽  
Release Rate ◽  
Recovery Rate ◽  
Slow Release ◽  
Italian Ryegrass ◽  
Dicalcium Phosphate ◽  
Emulsifiable Concentrate ◽  
Collection Period ◽  
Tablet Hardness ◽  
Leaching Columns

Metolachlor, applied to the surface of leaching columns as dicalcium phosphate tablets, was recovered over a period of 25 d compared with 2 and 3 d for emulsifiable concentrate and granular formulations, respectively. In similar studies, approximately 27% of napropamide was recovered from tablets during the same period. Adding an adjuvant to the napropamide tablet mixture increased the recovery rate to 55%. Tablet hardness and size had little effect on the release rate of napropamide. Tablets containing 4% ai napropamide released greater amounts of herbicide at a single collection period than did tablets containing 1% ai. Adding an adjuvant to the napropamide tablet mixture significantly improved Italian ryegrass control in the area adjacent to herbicide placement.

Release Rate of Three Herbicides from Controlled-Release Tablets

1989 ◽  
Vol 3 (2) ◽  
pp. 349-352 ◽  
Author(s):  
Stanley F. Gorski ◽  
Stephen Reiners ◽  
Michael A. Ruizzo
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
Italian Ryegrass ◽  
Dicalcium Phosphate ◽  
Controlled Release Tablets

Six, 9, and 12-mm diam dicalcium phosphate tablets were evaluated for their release of acetochlor, metolachlor, and metribuzin. Greenhouse bioassays with Italian ryegrass demonstrated that herbicides from the smaller tablets did not control grass as long as from the larger tablets. Italian ryegrass was controlled within a 5- to 7-cm diam circle around the 12-mm diam tablet and a 5-cm diam circle around the 6-mm diam tablet. All tested herbicides responded in a similar fashion. Six-mm diam tablets released metolachlor for 11 weeks, while the 12-mm tablet was active for 28 weeks.

Design and synthesis of periodic mesoporous organosilica materials with a multi-compartment structure

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 89397-89406 ◽  
Author(s):  
Chun Xiang Cynthia Lin ◽  
Siddharth Jambhrunkar ◽  
Pei Yuan ◽  
Chun Hui Clayton Zhou ◽  
George Xiu Song Zhao
Keyword(s):  
Anticancer Drug ◽  
Release Rate ◽  
Slow Release ◽  
Drug Carrier ◽  
High Loading ◽  
Loading Capacity ◽  
Periodic Mesoporous Organosilica ◽  
Design And Synthesis ◽  
Mesoporous Organosilica ◽  
Organosilica Materials

Multi-compartment periodic mesoporous organosilica materials show desirable properties as anticancer drug carrier with high loading capacity and slow release rate.

Gemcitabine Nanoparticles Improve the Activity of Ovarian Cancer Cells by Inhibiting CA-125 and Apoptosis-Related Proteins

2021 ◽  
Vol 11 (7) ◽  
pp. 1400-1405
Author(s):  
Sisi Yi ◽  
Chen Feng ◽  
Xiaohua Hu
Keyword(s):  
Ovarian Cancer ◽  
Cell Viability ◽  
Release Rate ◽  
Inhibitory Action ◽  
Encapsulation Efficiency ◽  
Slow Release ◽  
Drug Loading ◽  
Ca 125 ◽  
Ovarian Cancer Cells ◽  
Related Proteins

In recent years, the risk of ovarian cancer (OC) has become increasingly prevalent. Gemcitabine (GE) provides excellent inhibitory action on some solid tumors, but how it affects OC remains elusive. In the present research, we prepared GE nanoparticles (GEN) and analyzed OC cell viability under its intervention, hoping to conceive novel ideas for future clinical treatment of OC. Through experiments, we observed that the encapsulation efficiency and drug loading of GEN were observably higher than those of GE alone, and the release rate presented a stable slow release state. Under GEN intervention, the viability of OC cells was decreased, the apoptosis rate was elevated, and the apoptosis-related proteins were activated, while CA-125 was suppressed. Therefore, we can see that GEN exert favorable inhibitory action on OC cell viability, whose mechanism may be achieved through activating apoptosis-related proteins and inhibiting CA-125, which may be a new scheme for OC treatment in the future.

scholarly journals FORMULATION AND EVALUATION OF SIMVASTATIN GASTRORETENTIVE DRUG DELIVERY SYSTEM

2017 ◽  
Vol 9 (3) ◽  
pp. 55
Author(s):  
Manjunath P. N. ◽  
Satish C. S. ◽  
Vasanti S. ◽  
Preetham A. C. ◽  
Naidu Ras
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery System ◽  
Delivery System ◽  
Release Rate ◽  
Drug Transport ◽  
Hydroxypropyl Methylcellulose ◽  
In Vitro Dissolution ◽  
Dissolution Studies ◽  
Viscosity Grade

Objective: The aim of this study was to formulate and evaluate gastro retentive drug delivery system (GRRDS) using an effervescent approach for simvastatin.Methods: Floating tablets were prepared using directly compressible polymers hydroxypropyl methylcellulose (HPMC) K100M, HPMC K4M and carboxymethylcellulose sodium (NaCMC). The prepared tablets were subjected to pre-formulation studies like Compressibility index, Hausner ratio and post compression parameters like buoyancy/floating test and In vitro dissolution study.Results: Drug-excipient compatibility studies performed with the help of FTIR instrument indicated that there were no interactions. The DSC thermogram of the formulations revealed that crystalline form of simvastatin existed in the formulation which was confirmed by X-ray powder diffraction. Dissolution studies indicated that there was a decrease in the drug release with an increase in the polymer viscosity. The tablets prepared with low-viscosity grade HPMC K4M exhibited short Buoyancy Lag Time and floated for a longer duration as compared with formulations containing high viscosity grade HPMC K100M. The ‘n’ value for dissolution studies for all the formulations was found to be in the range of 0.647 to 0.975 indicating non-Fickian or anomalous drug transport. Conclusion: The drug release rate and floating duration of tablets depended on the nature of the polymer and other added excipients. The release rate of the drug can be optimized by using different ratios of polymers and other excipients. The formulation F8 achieved the optimized batch and complied with all the properties of the tablets.

Utilization of pyridoxal acetal salts as water-triggered, slow-release pro-fragrances

2018 ◽  
Vol 42 (19) ◽  
pp. 15538-15540 ◽  
Author(s):  
Kellie L. Weeks ◽  
Kyle R. Rutkowski ◽  
Arnold A. Morales Loyola ◽  
Gregory R. Boyce
Keyword(s):  
Delivery System ◽  
Slow Release ◽  
Vitamin B ◽  
Chemical Delivery System ◽  
Neutral Water

The use of vitamin B6 derivatives as a chemical delivery system for volatile alcohols initiated by neutral water is described.

STUDY OF THE DIFFERENT RELEASE CHARACTERISTICS OF ANTIBIOTICS FROM PATIENTS: A DYNAMIC ELUTING SYSTEM TO INVESTIGATE DRUG RELEASE FROM ANTIBIOTIC-IMPREGNATED CALCIUM SULFATE DELIVERY

2015 ◽  
Vol 15 (01) ◽  
pp. 1550012
Author(s):  
YANG ZHANG ◽  
RENJIE WU ◽  
YING HU ◽  
YU DONG ◽  
LIFENG SHEN ◽  
...  
Keyword(s):  
Drug Release ◽  
Delivery System ◽  
Release Rate ◽  
Calcium Sulfate ◽  
Fickian Diffusion ◽  
Release Behavior ◽  
Cumulative Release ◽  
In Vivo Release

Background: Antibiotic-impregnated calcium sulfate delivery systems (ACDS) are commonly used to treat chronic osteomyelitis. Our research is to investigate drug release in vitro over a longer period, as a cautious predictor of in vivo release. Methods: The local release behavior of antibiotic in vitro was simulated. The consecutive dynamic eluting experiment was performed based on the pro-operative characteristic of osteomyelitis patients and the determined results of drug concentration in the human drainage tissue fluid (DTF). The concentration of each drug in the receiving solution was detected by ultra-performance liquid chromatography-tandem quadrupole detector mass spectrometry. The ACDS was reviewed by scanning electronic microscopy (SEM) after 48 h, and prepared to be eluted for another examination after 33 days. The mechanism of antibiotic release was analyzed by using the Ritger–Peppas and Weibull equations. Results: The cumulative release rate of vancomycin in a vancomycin-calcium sulfate delivery system (VCDS) was 77.50 % (3.0 mm diameter) and 72.43 % (4.8 mm diameter), while that of the tobramycin in a tobramycin-calcium sulfate delivery system (TCDS) was 88.0 % (3.0 mm diameter) and 84.55 % (4.8 mm diameter). At the 15th day, approximately 27.92% of vancomycin was and 29.35% of tobramycin was released from the local implant in vivo. Using SEM, numerous vancomycin and tobramycin particles were found to be attached to the columnar calcium sulfate crystals at the start of the experiment. The release behavior of the two antibiotics followed a combination of Fickian diffusion and Case II transport mechanisms within the first 48 h, and a Fickian diffusion mechanism during the subsequent time period. The correlation coefficient of tobramycin and vancomycin in vivo and in vitro was 0.9704–0.9949 and 0.9549–0.9782, respectively. Conclusion: A good correlation of the in vivo and in vitro cumulative release rates was observed by comparing the cumulative release rate of drugs in vitro by means of the dynamic eluting model, and in the DTF. Therefore, our study has proved that it is possible to use the dynamic eluting model as a cautious predictor of in vivo release.

scholarly journals   Slow release and conventional N fertilizers for nutrition of bell pepper

2012 ◽  
Vol 58 (No. 6) ◽  
pp. 268-274 ◽  
Author(s):  
F. Stagnari ◽  
M. Pisante
Keyword(s):  
Dry Matter ◽  
Slow Release ◽  
Calcium Nitrate ◽  
Italian Ryegrass ◽  
Bell Pepper ◽  
Pot Experiment ◽  
N Recovery ◽  
Mineral Concentration ◽  
N Nutrition ◽  
N Fertilizers

Bell pepper (Capsicum annuum L.) high-quality and yield implies the management of N nutrition. Field and pot experiments with bell pepper and Italian ryegrass were carried out during 2009 and 2010. The experimental design included three N delaying fertilizers (Sulfammo Meta 46-5-0, controlled-release fertilizer; Nitrophoska Gold 15-9-15, slow-release fertilizer; Entec 26 26-0-0, stabilized fertilizer), two conventional N fertilizers, urea and calcium nitrate and one N-unfertilized control. The fertilizer’s rate was 150 kg N/ha. A pot experiment with bell pepper followed by ryegrass with the same fertilizers treatments was carried out in 2009. Dry matter (DM) yield, plant N concentration, plant N recovery and fruit mineral concentration were measured. Calcium nitrate and urea produced statistically higher DM in both field and pots. Sulfammo Meta produced always lower yields. In the field plants recovered a minimum of 18% and a maximum of 82% of the N applied, respectively, in Sulfammo Meta and calcium nitrate. In the pot experiment, bell pepper + ryegrass recovered only 32.5% of N applied with Sulfammo Meta and nearly 100% of N applied in the other fertilized pots. None of the slow-release N materials provided clear advantages over conventional fertilizers to be used in this crop.  

scholarly journals Formulation and Characterization of Eplerenone Nanoemulsion Liquisolids, An Oral Delivery System with Higher Release Rate and Improved Bioavailability

Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Ahmed Khames
Keyword(s):  
Drug Release ◽  
Delivery System ◽  
Release Rate ◽  
Oral Delivery ◽  
Oral Route ◽  
Drug Release Rate ◽  
Enhanced Absorption ◽  
Oral Delivery System ◽  
Characterization Studies

Because Eplerenone (EPL) is a Biopharmaceutical Classification System (BCS) class-II drug and is prone to extensive liver degradation, it suffers from poor bioavailability after oral administration. This work aimed to prepare liquisolids loaded with EPL-nanoemulsions (EPL-NEs) that have a higher drug release rate and improved bioavailability by the oral route. Based on solubility studies, mixtures of Triacetin (oil) and Kolliphor EL/PEG 400 surfactant/co-surfactant (Smix) in different ratios were used to prepare EPL-NE systems, which were characterized and optimized for droplet size, zeta potential, polydispersity index (PDI), and drug content. Systems were then loaded onto liquisolid formulations and fully evaluated. A liquisolid formulation with better drug release and tableting properties was selected and compared to EPL-NEs and conventional EPL oral tablets in solid-state characterization studies and bioavailability studies in rabbits. Only five NEs prepared at 1:3, 1:2, and 3:1 Smix met the specified optimization criteria. The drug release rate from liquisolids was significantly increased (90% within 45 minutes). EPL-NE also showed significantly improved drug release but with a sustained pattern for four hours. Liquisolid bioavailability reached 2.1 and 1.2 relative to conventional tablets and EPL-NE. This suggests that the EPL-NE liquisolid is a promising oral delivery system with a higher drug release rate, enhanced absorption, decreased liver degradation, and improved bioavailability.

scholarly journals A predictive model for Covid-19 spread – with application to eight US states and how to end the pandemic

2020 ◽  
Vol 148 ◽  
Author(s):  
Z. S. Khan ◽  
F. Van Bussel ◽  
F. Hussain
Keyword(s):  
Predictive Model ◽  
Release Rate ◽  
Recovery Rate ◽  
Death Rate ◽  
Compartmental Model ◽  
Contact Rate ◽  
Reinfection Rate ◽  
Us States ◽  
Coupled Equations ◽  
The Us

Abstract A compartmental model is proposed to predict the coronavirus 2019 (Covid-19) spread. It considers: detected and undetected infected populations, social sequestration, release from sequestration, plus reinfection. This model, consisting of seven coupled equations, has eight coefficients which are evaluated by fitting data for eight US states that make up 43% of the US population. The evolution of Covid-19 is fairly similar among the states: variations in contact and undetected recovery rates remain below 5%; however, variations are larger in recovery rate, death rate, reinfection rate, sequestration adherence and release rate from sequestration. Projections based on the current situation indicate that Covid-19 will become endemic. If lockdowns had been kept in place, the number of deaths would most likely have been significantly lower in states that opened up. Additionally, we predict that decreasing contact rate by 10%, or increasing testing by approximately 15%, or doubling lockdown compliance (from the current ~15% to ~30%) will eradicate infections in Texas within a year. Extending our fits for all of the US states, we predict about 11 million total infections (including undetected), and 8 million cumulative confirmed cases by 1 November 2020.

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