PT  - JOURNAL ARTICLE
AU  - Lostritto, R. T.
AU  - Silvestri, S. L.
TI  - Temperature and Cosurfactant Effects on Lidocaine Release from Submicron Oil in Water Emulsions
DP  - 1987 Nov 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 220--224
VI  - 41
IP  - 6
4099  - http://journal.pda.org/content/41/6/220.short
4100  - http://journal.pda.org/content/41/6/220.full
SO  - PDA J Pharm Sci Technol1987 Nov 01; 41
AB  - The importance of interfacial interactions affecting drug release from O/W submicron emulsions has been demonstrated. In this study, the effect of temperature (25-40 ° C) and cosurfactant concentration on the release of lidocaine from 30% sesame oil in water submicron emulsions is evaluated. All emulsions contained three percent of a nonionic surfactant (HLB = 10) and were prepared using the Microfluidizer® device. The cosurfactant, sodium lauryl sulfate (SLS), was added in concentrations ranging from zero to one percent and was used to manipulate the O/W interfacial adsorption of lidocaine. Increased interfacial adsorption of lidocaine is reflected by greater L values and correspondingly lower drug release rates in vitro as measured by free drug release across a semipermeable membrane. Increasing the SLS concentration does increase L and decrease the drug release rate. A linear estimation is developed to quantify this phenomena. The thermal effects are biphasic, exhibiting a peak L value(minimum release rate) at 30 °C. Relevant mechanisms involving temperature dependent hydrogen bonding and mobility changes are proposed to explain these observations.