Cellulose Diacetate/Organoclay Nanocomposites as Controlled Release Matrices for Pest Control Applications

Author(s):  
Thabang N. Mphateng ◽  
Antonio B. Mapossa ◽  
James Wesley-Smith ◽  
Shatish Ramjee ◽  
Walter W Focke

Abstract This study aimed to develop cellulose-based polymer matrices as controlled release devices for plant-based insect repellents and attractants, with the aim of finding sustainable and environmentally friendly pest control methods for agricultural applications. Citronellol, terpineol and methyl salicylate were the selected active compounds for this study. Their compatibility with cellulose diacetate was predicted using Hansen Solubility Parameters, which predicted terpineol as the most compatible with cellulose diacetate, followed by methyl salicylate and citronellol. This was consistent with the plasticization efficiency trend from DMA results of solvent cast cellulose diacetate films containing the active compounds. The chemical identity of the films and cellulose diacetate-active compound intermolecular interactions were verified by FTIR. TGA demonstrated the thermal stability of cellulose diacetate/active compound/clay formulations at temperatures not exceeding 170 °C. Cellulose diacetate/organoclay nanocomposite matrices containing the active compounds at 35 wt-% were prepared by twin screw extrusion compounding, with the active compounds also functioning as plasticizers. The amount of active compound in the strands was determined by solvent extraction and TGA. Both methods showed that small amounts of active compound were lost during the compounding process. SEM demonstrated the effect of organoclay on the internal morphology of the matrix, whereas TEM showed clay dispersion and intercalation within the matrix. The matrix served as a reservoir for the active compounds while simultaneously controlling their release into the environment. Release profiles, obtained through oven ageing at 40 °C for 70 days, were fitted to existing Log-logistic and Weibull models, and novel Diffusion and Modified Weibull release models. Citronellol was released the fastest, followed by methyl salicylate and terpineol. The findings suggest that cellulose diacetate/organoclay strands are promising controlled-release matrices for pest control purposes.

Heliyon ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. e01853 ◽  
Author(s):  
Yuki Kato ◽  
Shinichi Tsutsumi ◽  
Nobuyuki Fujiwara ◽  
Hideki Yamamoto

2018 ◽  
Vol 69 (1) ◽  
pp. 34-37 ◽  
Author(s):  
Monica Ihos ◽  
Corneliu Bogatu ◽  
Carmen Lazau ◽  
Florica Manea ◽  
Rodica Pode

The aim of this study was the investigation of photocatalytic degradation of pharmaceutically active compounds using doped TiO2 functionalized zeolite photocatalyst. Diclofenac (DCF), a non-steroidal anti-inflammatory drug, that represents a biorefractory micropollutant, was chosen as model of pharmaceutically active compound. The photocatalyst was Z-TiO2-Ag. The concentration of DCF in the working solutions was 10 mg/L,50 mg/L,100 mg/L and 200 mg/L and of photocatalyst 1 g/L in any experiments. The process was monitored by recording the UV spectra of the treated solutions and total organic carbon (TOC) determination. The UV spectra analysis and TOC removal proved that along the advanced degradation of DCF also a mineralization process occurred. The carried out research provided useful information envisaging the treatment of pharmaceutical effluents by photocatalysis.


2020 ◽  
Vol 14 (1) ◽  
pp. 21-39
Author(s):  
Anupama Singh ◽  
Vandana Kharb ◽  
Vikas Anand Saharan

Fast Dissolving/Disintegrating Dosage Forms (FDDFs) are a group of dosage forms which dissolve or disintegrate quickly, leading to fast distribution of active ingredients at the site of administration; thereby providing ease of oral ingestion of solid unit dosage forms and have the potential to enhance transmucosal absorption. With time, the use of FDDFs in alternative systems has significantly increased. Homeopathic systems and traditional Chinese medicine have embraced FDDFs for the delivery of active compounds. Most of the patents in this area are from China or by the Chinese innovators. In Europe and US, FDDFs have been extensively studied for the delivery of natural active compounds. It was fascinating to know that some new dosage forms and new routes of delivering active compounds are also making their way to the family of FDDFs. The dose of active compound, size of dosage forms, standardization of extracts, polyherbal mixtures, stability of active compounds, safety, efficacy and pharmacokinetics are challenging issues for developing FDDF herbal formulations or phytopharmaceuticals.


2021 ◽  
Author(s):  
Ouassef Nahi ◽  
Alexander N. Kulak ◽  
Thomas Kress ◽  
Yi-Yeoun Kim ◽  
Ola G. Grendal ◽  
...  

Nanocarriers have tremendous potential for the encapsulation, storage and delivery of active compounds.


Burns ◽  
2021 ◽  
Author(s):  
Maryam Hosseini ◽  
Michael S. Roberts ◽  
Reza Aboofazeli ◽  
Hamid R. Moghimi

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 816
Author(s):  
Yuxuan Ge ◽  
Zhenhua Hu ◽  
Jili Chen ◽  
Yujie Qin ◽  
Fei Wu ◽  
...  

GLP-1 receptor agonists are a class of diabetes medicines offering self-regulating glycemic efficacy and may best be administrated in long-acting forms. Among GLP-1 receptor agonists, exenatide is the one requiring the least dose so that controlled-release poly(d, l-lactic-co-glycolic acid) (PLGA) microspheres may best achieve this purpose. Based on this consideration, the present study extended the injection interval of exenatide microspheres from one week of the current dosage form to four weeks by simply blending Mg(OH)2 powder within the matrix of PLGA microspheres. Mg(OH)2 served as the diffusion channel creator in the earlier stage of the controlled-release period and the decelerator of the self-catalyzed degradation of PLGA (by the formed lactic and glycolic acids) in the later stage due to its pH-responsive solubility. As a result, exenatide gradually diffused from the microspheres through Mg(OH)2-created diffusion channels before degradation of the PLGA matrix, followed by a mild release due to Mg(OH)2-buffered degradation of the polymer skeleton. In addition, an extruding–settling process comprising squeezing the PLGA solution through a porous glass membrane and sedimentation-aided solidification of the PLGA droplets was used to prepare the microspheres to ensure narrow size distribution and 95% encapsulation efficiency in an aqueous continuous phase. A pharmacokinetic study using rhesus monkey model confirmed the above formulation design by showing a steady blood concentration profile of exenatide with reduced CMAX and dosage form index. Mg·(OH)2


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3091
Author(s):  
Mohammed Ghazwani ◽  
Prawez Alam ◽  
Mohammed H. Alqarni ◽  
Hasan S. Yusufoglu ◽  
Faiyaz Shakeel

This research deals with the determination of solubility, Hansen solubility parameters, dissolution properties, enthalpy–entropy compensation, and computational modeling of a naturally-derived bioactive compound trans-resveratrol (TRV) in water, methanol, ethanol, n-propanol, n-butanol, propylene glycol (PG), and various PG + water mixtures. The solubility of TRV in six different mono-solvents and various PG + water mixtures was determined at 298.2–318.2 K and 0.1 MPa. The measured experimental solubility values of TRV were regressed using six different computational/theoretical models, including van’t Hoff, Apelblat, Buchowski–Ksiazczak λh, Yalkowsly–Roseman, Jouyban–Acree, and van’t Hoff–Jouyban–Acree models, with average uncertainties of less than 3.0%. The maxima of TRV solubility in mole fraction was obtained in neat PG (2.62 × 10−2) at 318.2 K. However, the minima of TRV solubility in the mole fraction was recorded in neat water (3.12 × 10−6) at 298.2 K. Thermodynamic calculation of TRV dissolution properties suggested an endothermic and entropy-driven dissolution of TRV in all studied mono-solvents and various PG + water mixtures. Solvation behavior evaluation indicated an enthalpy-driven mechanism as the main mechanism for TRV solvation. Based on these data and observations, PG has been chosen as the best mono-solvent for TRV solubilization.


Sign in / Sign up

Export Citation Format

Share Document