Patent ID: 6193974
Filing Date: 2001-02-27
Classification: A01N

Abstract:
A process for preparing a storage stable Azadirachtin enriched Azadirachtin A pesticidal composition, comprising the steps of:(a) passing at least three batches of an aqueous polar solvent through decorticated and pelleted neem seeds to obtain a solvent extract without oozing neem oil from said seeds;(b) removing Azadirachtin A from said solvent extract with a polar solvent to obtain an Azadirachtin A solution;(c) removing the polar solvent from the Azadirachtin A solution to obtain a concentrated Azadirachtin A solution;(d) removing trace oil and hydrophobic impurities from the concentrated Azadirachtin A solution with a non-polar solvent;(e) removing water from the concentrated Azadirachtin A solution;(f) recovering a substantially purified Azadirachtin A powder;(g) diluting the substantially purified Azadirachtin A powder with ethanol:water in proportions in the range 100-70:0-30 (volume/volume) to a concentration of 2000-40,000 ppm Azadirachtin containing 1,000-20,000 ppm of Azadirachtin A (weight/volume);(h) emulsifying the diluted Azadirachtin with 0.2% to 30% (volume/volume) of a non-ionic and non-toxic emulsifying agent and adding neem oil in the ratio of 20-50% (volume/volume) of the composition;(i) adjusting the pH of the emulsified diluted Azadirachtin to 3.5 to 6.0 by adding an alkali solution; and(j) adding 1-2.5% sunscreen agent comprising one of para-amino benzoic acid (PABA) or its ester after pH adjustment to stabilize the resultant composition.