CN111280172A

CN111280172A - Gibberellin sustained-release microcapsule and preparation method thereof

Info

Publication number: CN111280172A
Application number: CN201811499579.5A
Authority: CN
Inventors: 尹恒; 谢红国
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2018-12-09
Filing date: 2018-12-09
Publication date: 2020-06-16

Abstract

The invention relates to a gibberellin sustained-release microcapsule and a preparation method thereof. The microcapsule comprises the following specific preparation steps: dissolving gibberellin original drug, surfactant and cosurfactant in an organic solvent to obtain a solution A; dissolving the wall material to obtain a solution B; slowly and dropwise adding the solution A into the solution B under the stirring condition, continuously stirring for 30min to obtain gibberellin emulsion, and preparing the gibberellin sustained-release microcapsules by spray drying. The grain diameter range of the gibberellin sustained-release microcapsules prepared by the method is 0.5-20 mu m. The invention can solve the problems of poor stability, low utilization rate, short duration and the like of the traditional preparation.

Description

Gibberellin sustained-release microcapsule and preparation method thereof

Technical Field

The invention relates to the field of plant growth regulators and pesticides, in particular to the technical field of processing of plant growth regulators and pesticide formulations, and specifically relates to a preparation method of gibberellin microcapsules and a gibberellin microcapsule product.

Technical Field

Gibberellins, a ubiquitous plant hormone. The chemical structure belongs to diterpenoid acid and is derived from a tetracyclic skeleton. Can promote the growth of stems and leaves, promote bolting and flowering in advance, promote the germination of seeds, tubers and root tubers, stimulate the growth of fruits, increase the fruiting rate or form seedless fruits and the like. It can be used for increasing yield of potato, tomato, rice, wheat, cotton, soybean, pea, tobacco, fruit tree, etc. However, when the gibberellin is excessively applied, yellow and slender branches of the plants can appear, namely the plants lose green and grow excessively, and the yield is influenced. At present, missible oil, crystal powder, soluble tablets, soluble granules and the like are taken as main materials in the market, and the problems of poor stability, low effective utilization rate, short lasting period and the like exist.

The slow release technology can effectively solve the problems of high release speed and short effective action time of the pesticide active preparation, and reduce or avoid the adverse effect of the pesticide so as to prolong the service life of the pesticide. The microcapsule formulation has the highest technical content in various pesticide sustained-release formulations at present. The active ingredients (core materials) are embedded in capsule wall materials to form a micro-sphere preparation, the diameter of the micro-sphere preparation is several micrometers to several hundred micrometers, and the core materials are slowly released through the capsule wall. It will become the development direction of new pesticide formulation in future.

Disclosure of Invention

The invention aims to solve the technical problem of providing a gibberellin sustained-release microcapsule and a preparation method thereof, and solves the problems of poor stability, low utilization rate, short duration and the like of the traditional pesticide preparation.

The invention uses one or more than two of gelatin, dextran, polyvinyl alcohol, collagen, Arabic gum and flaxseed gum as wall materials to prepare the slow-release microcapsule with gibberellin embedded in the wall materials by a spray drying method. The characterization result shows that the prepared microcapsule has a regular shape, and also has good encapsulation efficiency, drug-loading rate and slow-release performance.

The gibberellin sustained-release microcapsule overcomes the defects of poor stability, low effective utilization rate, short duration and the like of the existing gibberellin, has the advantages of high stability, long duration, high utilization rate and the like, and has wide application value and market potential.

The invention provides a gibberellin sustained-release microcapsule, wherein the wall material of the microcapsule is at least one of gelatin, glucan, polyvinyl alcohol, collagen, Arabic gum and flaxseed gum; the core material of the microcapsule is gibberellin; the grain diameter of the microcapsule is 0.5-20 μm; the thickness of the wall material is 0.1-9.9 μm; the weight ratio of the wall material to the core material is 0.5-150.

The invention also provides a gibberellin sustained-release microcapsule and a preparation method thereof: the method comprises the following steps:

(1) respectively weighing gibberellin original drug and surfactant, dissolving in organic solvent, and making the concentrations of gibberellin original drug and surfactant in the solution respectively be 0.5-50mg/ml and 0-40mg/ml, so as to obtain solution A; weighing wall materials to prepare a solution with the concentration of 0.5-20mg/ml to obtain a solution B.

(2) Slowly dropwise adding the solution A into the solution B according to the volume ratio of the solution A to the solution B of 1:1-4 under the stirring condition, and continuously stirring for 30min to obtain gibberellin emulsion.

(3) Spraying the gibberellin emulsion, drying in a spray dryer, controlling the air inlet temperature at 180-200 ℃ and the air outlet temperature at 70-100 ℃ to obtain microcapsule powder, and collecting the powder to obtain the gibberellin sustained-release microcapsule product.

Based on the technical scheme, preferably, the organic solvent is methanol, ethanol or ethyl acetate.

Based on the above technical scheme, preferably, the surfactant is one or more than 2 of tween 20, tween 40, tween 60, tween 80, lecithin, polyoxyethylene 400 monolaurate, polyoxyethylene 400 monostearate and polyoxyethylene 400 monooleate.

Advantageous effects

(1) The invention uses gelatin, glucan, polyvinyl alcohol, collagen, Arabic gum and flaxseed gum which can be degraded by environmental microorganisms as coating materials, the coating effect is good, and the degradation products of the coating materials have no pollution to the environment;

(2) the gibberellin microcapsules coated by gelatin, glucan, polyvinyl alcohol, collagen, Arabic gum and flaxseed gum are adopted, so that the medicament is slowly released and is not easy to generate phytotoxicity;

(3) under the condition of the same dosage, the gibberellin microcapsules coated by gelatin, glucan, polyvinyl alcohol, collagen, Arabic gum and flaxseed gum can keep the drug effect for a longer time.

Detailed Description

Drawings

FIG. 1 is a graph showing the cumulative release of the microcapsules prepared in example 1 and the gibberellin powder of comparative example 1.

Example 1

Respectively weighing gibberellin original drug and tween-20, dissolving in ethanol, and making the concentrations of gibberellin original drug and surfactant in the solution respectively be 50mg/ml and 5mg/ml to obtain solution A; weighing polyvinyl alcohol, dissolving in warm water to prepare a solution with the concentration of 20mg/ml, and obtaining a solution B. Slowly and dropwise adding 1 volume of the solution A into 4 volumes of the solution B under the stirring condition, and continuously stirring for 30 min. And (3) carrying out spray drying on the emulsion, controlling the air inlet temperature to be 190 ℃ and the air outlet temperature to be 80 ℃ to obtain microcapsule powder, and collecting the powder to obtain the gibberellin sustained-release microcapsule product. The microcapsule has particle diameter of 0.5-20 μm.

Example 2

Respectively weighing gibberellin original drug and tween-20, dissolving in ethyl acetate, and making the concentrations of gibberellin original drug and surfactant in the solution respectively be 20mg/ml and 40mg/ml, to obtain solution A; weighing gelatin, dissolving in warm water to obtain 10mg/ml solution B. Slowly and dropwise adding 1 volume of the solution A into 1 volume of the solution B under the stirring condition, and continuously stirring for 30 min. And (3) carrying out spray drying on the emulsion, controlling the air inlet temperature to be 185 ℃ and the air outlet temperature to be 80 ℃ to obtain microcapsule powder, and collecting the powder to obtain the gibberellin sustained-release microcapsule product. The microcapsule has particle diameter of 0.5-15 μm.

Example 3

Respectively weighing gibberellin original drug and lecithin, dissolving in ethanol, and making the concentrations of gibberellin original drug and surfactant in the solution respectively be 0.5mg/ml and 10mg/ml to obtain solution A; weighing Arabic gum, dissolving in warm water, and making into 1mg/ml solution to obtain solution B. Slowly and dropwise adding 1 volume of the solution A into 2 volumes of the solution B under the stirring condition, and continuously stirring for 30 min. And (3) carrying out spray drying on the emulsion, controlling the air inlet temperature to be 200 ℃ and the air outlet temperature to be 70 ℃ to obtain microcapsule powder, and collecting the powder to obtain the gibberellin sustained-release microcapsule product. The microcapsule has particle diameter of 1-10 μm.

Example 4

Respectively weighing gibberellin original drug and lecithin, dissolving in methanol, and making the concentrations of gibberellin original drug and surfactant in the solution respectively be 20mg/ml and 40mg/ml to obtain solution A; weighing polyvinyl alcohol, dissolving in warm water to prepare a solution with the concentration of 20mg/ml, and obtaining a solution B. Slowly and dropwise adding 1 volume of the solution A into 1 volume of the solution B under the stirring condition, and continuously stirring for 30 min. And (3) carrying out spray drying on the emulsion, controlling the air inlet temperature to be 190 ℃ and the air outlet temperature to be 70 ℃ to obtain microcapsule powder, and collecting the powder to obtain the gibberellin sustained-release microcapsule product. The microcapsule has particle diameter of 0.5-20 μm.

Comparative example 1

Gibberellin powder was used as a comparative example.

Example 5

Respectively taking 0.1g of the gibberellin sustained-release microcapsules prepared in the embodiments 1-4 and gibberellin powder in the comparative example 1, respectively dispersing the gibberellin sustained-release microcapsules and the gibberellin powder in 10mL of deionized water, placing the deionized water at room temperature, taking liquid samples at equal intervals, and measuring the concentration of azoxystrobin in the solution by using an ultraviolet spectrophotometer; the sustained release performance was evaluated by the cumulative release amount, which was calculated by the following formula.

Cumulative release amount n days total cumulative release amount of gibberellin (1)

FIG. 1 is a graph showing the release effect of gibberellin from gibberellin sustained-release microcapsules prepared in example 1 of the present invention and gibberellin powder of comparative example 1, which illustrates that the controlled-release effect of gibberellin sustained-release microcapsules is better.

Claims

1. A gibberellin sustained-release microcapsule is characterized in that the wall material of the microcapsule is at least one of gelatin, glucan, polyvinyl alcohol, collagen, Arabic gum and flaxseed gum; the core material of the microcapsule is gibberellin; the grain diameter of the microcapsule is 0.5-20 μm; the thickness of the wall material is 0.1-9.9 μm; the weight ratio of the wall material to the core material is 0.5-150.

2. A method for preparing a gibberellin sustained-release microcapsule according to claim 1, wherein: the method comprises the following steps:

(1) respectively weighing gibberellin original drug and surfactant, and dissolving in an organic solvent to obtain a solution A; the concentrations of the gibberellin original drug and the surfactant in the solution A are 0.5-50mg/ml and 0-40mg/ml respectively, and the wall material is weighed to prepare a solution B of 0.5-20 mg/ml;

(2) slowly dropwise adding the solution A into the solution B according to the volume ratio of the solution A to the solution B of 1:1-4 under the stirring condition, and continuously stirring for 30min to obtain gibberellin emulsion;

(3) spraying gibberellin emulsion, drying in a spray dryer to obtain microcapsule powder, and collecting the powder to obtain the gibberellin sustained-release microcapsule; the air inlet temperature of the spray drying agent is 180-200 ℃, and the air outlet temperature is controlled to be 70-100 ℃.

3. The method of claim 1, wherein: the organic solvent is methanol, ethanol or ethyl acetate.

4. The method of claim 1, wherein: the surfactant is one or more than 2 of Tween 20, Tween 40, Tween 60, Tween 80, lecithin, polyoxyethylene 400 monolaurate, polyoxyethylene 400 monostearate, and polyoxyethylene 400 monooleate.