Halloysite nanocontainers for controlled delivery of Gibberellic Acid

Abstract

Inorganic halloysite nanocontainers were employed for controlled delivery of plant growth regulator (PGR)–Gibberellic Acid. The cylindrical geometry of nanocontainer was found to be found to indicate 600 ± 200 nm length and 50 ± 10 nm outer diameter with inner lumen to be in the range of 12–15 nm. Attempts were made to encapsulate GA and obtain controlled release in aqueous buffer through nanocontainers capped with a copper stopper. Halloysite nanocontainers were characterized using TEM, EDX and TGA. In vitro release studies of GA in water were studied wherein the pH of the solution was maintained using phosphate buffer. Increase in amount of copper was found to be successful in retarding the amount of GA release. Complex between GA and copper ions was found to be responsible for the stopper formation. For tube stopper opening, addition of excessive amounts of ammonia solution was added. Parameters such as effect of temperature, pH and UV light were studied in detail. Encapsulation and stopper formation onto the nanocontainer was found to effective in achieving overall release control. Kinetic release model proposed by Peppas was analyzed for best fit.