02073nas a2200265 4500008004100000022001400041245010100055210006900156260000800225300001100233490000800244520120200252653002301454653002501477653001801502653002301520653001901543653001801562100002401580700001701604700001901621700001701640700003101657856011901688 2023 eng d a0927-775700aDouble encapsulation of liquid active compounds using nanoclay reinforced polyurea microcapsules0 aDouble encapsulation of liquid active compounds using nanoclay r cDEC a1325470 v6793 a

In recent years, there has been growing interest in the double encapsulation of drugs, agrochemicals, and fragrances, aiming to achieve the highest encapsulation efficiency and preserve the activity of the encapsulated core over an extended duration. However, when active ingredients in liquid form are double encapsulated, preventing the rupture of primary microcapsules during the second encapsulation process and the leakage of the encapsulated core are major challenges. This report describes a method that utilizes polyurea and starch for successful double encapsulation of dimethyl phthalate (DMP), a liquid insect-repellent, as a model active component. We demonstrate that the incorporation of 3 wt% montmorillonite (MMT) nanoclay strengthens the polyurea wall of the primary microcapsule and prevents its rupture during double encapsulation with starch. This process facilitates the uniform distribution of polyurea microcapsules within the starch matrix and significantly improves the mechanical integrity of the nanocomposite microcapsules embedded in starch. The double-encapsulated system developed in this study significantly reduces the release rate of encapsulated DMP.

10aControlled release10aDouble encapsulation10aMicrocapsules10aMicroencapsulation10aNanocomposites10aStarch matrix1 aAher, Yogeshwar, P.1 aTorris, Arun1 aAdhikari, Benu1 aShukla, Ravi1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/double-encapsulation-liquid-active-compounds-using-nanoclay-reinforced-polyurea03011nas a2200181 4500008004100000245011000041210006900151260000800220300001600228490000600244520233800250100002402588700001902612700001702631700001802648700003102666856013202697 2025 eng d00aDouble-encapsulated controlled release system for the staged delivery of a growth stimulant and herbicide0 aDoubleencapsulated controlled release system for the staged deli cAPR a1047–10560 v53 a

Weed control remains a critical challenge in agriculture, especially with parasitic weeds such as Orobanche spp., Striga spp., and Cuscuta spp., which significantly reduce crop yield. Although herbicides are effective against common weeds, they are less effective against parasitic weeds due to their unique germination mechanisms and close association with host plants. Growth regulators can stimulate the germination of parasitic weeds (suicidal germination) in the absence of host plants, providing a potential opportunity for controlling parasitic weeds, especially Striga sps. We report here a double-encapsulated staged delivery system, wherein herbicide (atrazine) is encapsulated in the inner polyurea shell and a growth stimulant (Gibberellic acid, GA3) in the outer alginate matrix. In vitro release study conducted in an aqueous medium showed that the time required for 50% release of atrazine from this double-encapsulated system is 96 h against 3 h for GA3. The quick release of GA3, followed by a slow and sustained release of atrazine, is expected to first induce the germination of parasitic weed seeds using GA3 and subsequently exterminate them upon exposure to atrazine. Interpretation of release data using the Weibull model led to the conclusion that the release of atrazine and GA3 is primarily governed by Fickian diffusion. Soil breakthrough profile shows that double encapsulation of atrazine helps to control the overleaching of atrazine into the soil.

1 aAher, Yogeshwar, P.1 aAdhikari, Benu1 aShukla, Ravi1 aMarimuthu, S.1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/double-encapsulated-controlled-release-system-staged-delivery-growth-stimulant-and-herbicide