dc.description.abstract | Process parameters and stability evaluation
are important to develop a new formulation.
Since Neem oil and Tween 20® are cheap,
less toxic, highly available and affordable,
these were chosen to formulate the emulsion.
Objectives of the study were to formulate a
stable emulsion consisting of Neem oil and
Tween 20® and to evaluate the stability of the
optimized formulations. Primary emulsions were
formulated in different ratios of oil, water and
surfactant by using the magnetic stirrer (300 rpm).
Respective secondary emulsions were obtained
by high shear homogenization (10,000 rpm) of
optimized formulations of primary emulsions.
Samples were subjected to centrifugation (1200
rpm) to determine the accelerated stability. All
the optimized formulations of primary and
secondary emulsions were subjected to observe
short-term stability, accelerated stability for 14
days and long-term stability for 90 days. Most of
the samples of primary and secondary emulsions
were stable throughout the short-term stability
evaluation period except one primary and two
secondary emulsions. Most of the secondary
emulsions showed greater stability period than
that of respective primary emulsions. Creaming
and phase separation were the main unstable
conditions that occurred during the long term
stability evaluation period. Two primary
emulsions and one secondary emulsion showed
instability during the accelerated stability
evaluation period. The best formula consisted of
45% Neem oil, 35% water and 20% Tween 20®.
Secondary homogenization led to enhance the
stability of the formulations.. | en_US |