TY - JOUR
T1 - Physostigmine emulsion
T2 - a new injectable controlled release delivery system
AU - Benita, Simon
AU - Friedman, Doron
AU - Weinstock, Marta
PY - 1986/5
Y1 - 1986/5
N2 - Physostigmine salicylate was incorporated in a soybean injectable emulsion in an attempt to control the drug release from the emulsion. In vitro examination of the physicochemical properties of the emulsions revealed that a mixture of an anionic (phospholipid) and non-ionic surfactant (Pluronic) was required to prepare stable physostigmine emulsions. Variation in concentration of either the anionic or non-ionic emulsifier decreased the mean droplet size while the zeta potential did not show any clear correlation with increasing phospholipid concentration but decreased, reached a plateau and fell again with increasing Pluronic concentration. In the presence of physostigmine salicylate. instability was introduced which changed the profile of zeta potential dependency on phospholipids and Pluronic concentrations. Zeta potential increased with physostigmine concentration as a result of increasing ionization of various polar groups at the oil-water droplet interface. Moreover, physostigmine incorporated in the emulsion was protected from its aqueous decomposition and remained intact. Stable physostigmine emulsions preserved over long periods of time were obtained using appropriate experimental conditions probably as a result of optimization of effects due to surface potential increase, droplet size reduction and formation of a resistant close-packed interfacial mixed film. which confers steric stabilization to the dispersed droplets.
AB - Physostigmine salicylate was incorporated in a soybean injectable emulsion in an attempt to control the drug release from the emulsion. In vitro examination of the physicochemical properties of the emulsions revealed that a mixture of an anionic (phospholipid) and non-ionic surfactant (Pluronic) was required to prepare stable physostigmine emulsions. Variation in concentration of either the anionic or non-ionic emulsifier decreased the mean droplet size while the zeta potential did not show any clear correlation with increasing phospholipid concentration but decreased, reached a plateau and fell again with increasing Pluronic concentration. In the presence of physostigmine salicylate. instability was introduced which changed the profile of zeta potential dependency on phospholipids and Pluronic concentrations. Zeta potential increased with physostigmine concentration as a result of increasing ionization of various polar groups at the oil-water droplet interface. Moreover, physostigmine incorporated in the emulsion was protected from its aqueous decomposition and remained intact. Stable physostigmine emulsions preserved over long periods of time were obtained using appropriate experimental conditions probably as a result of optimization of effects due to surface potential increase, droplet size reduction and formation of a resistant close-packed interfacial mixed film. which confers steric stabilization to the dispersed droplets.
KW - physostigmine salicylate-injectable emulsion-controlled-release delivery system
UR - http://www.scopus.com/inward/record.url?scp=0022598146&partnerID=8YFLogxK
U2 - 10.1016/0378-5173(86)90134-1
DO - 10.1016/0378-5173(86)90134-1
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AN - SCOPUS:0022598146
SN - 0378-5173
VL - 30
SP - 47
EP - 55
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
IS - 1
ER -