Particle size analysis of concentrated phospholipid microemulsions: I. Total intensity light scattering
Journal Title: The AAPS Journal - Year 2000, Vol 2, Issue 2
Abstract
Water-in-oil phospholipid microemulsions prepared from a constant total surfactant/cosurfactant concentration of 25 wt% at four different lecithin/alcohol weight ratios (Km of 1∶1, 1.5∶1, 1.77∶1, and 1.94∶1) and containing water concentrations (or volume fractions) ranging from 2.0 to 26 wt% (or 0.04 to 0.26) have been examined at 298 K using total intensity light scattering. The data obtained were analysed using the hard-sphere model of Percus-Yevick, modified to account for the partitioning of the alcohol between the various phases. The light-scattering results showed that, regardless of the Km or the alcohol used, a minimum water concentration of at least 9 wt% was required for the formation of a microemulsion; although this value was reasonably constant for each of the alcohols investigated, there was a tendency for a slightly higher concentration of water to be required for microemulsion formation at higher Km values. Simple calculations suggested that a microemulsion was formed only when sufficient water was present to satisfy the hydration of both the phospholipid head groups and the hydroxyl groups of the cosurfactant associated with the droplet. At water concentrations lower than this minimum value, a cosolvent system was observed. In all systems above this minimum concentration, as the concentration of water increased, the size of the microemulsion droplets also increased. Surprisingly, however, there was little difference in the size of the microemulsion droplets obtained with the different alcohols, regardless of the Km, although for a particular alcohol there was some indication that the higher Km systems produced the slightly smaller droplets for an equivalent water concentration. There was also a suggestion that the more hydrophobic alcohols produced slightly smaller droplets than the more polar alcohols at the same Km.
Authors and Affiliations
Reza Aboofazeli, David J. Barlow, M. Jayne Lawrence
Keywords
Related Articles
- EP ID EP682083
- DOI 10.1208/ps020213
- Views 60
- Downloads 0
Application of Absorption Modeling in Rational Design of Drug Product Under Quality-by-Design Paradigm
Physiologically based absorption models can be an important tool in understanding product performance and hence implementation of Quality by Design (QbD) in drug product development. In this report, we show several case...
Current Methods for Predicting Human Food Effect
Food can impact the pharmacokinetics of a drug product through several mechanisms, including but not limited to, enhancement in drug solubility, changes in GI physiology, or direct interaction with the drug. Significant...
Human Cannabinoid 1 GPCR C-Terminal Domain Interacts with Bilayer Phospholipids to Modulate the Structure of its Membrane Environment
G protein-coupled receptors (GPCRs) play critical physiological and therapeutic roles. The human cannabinoid 1 GPCR (hCB1) is a prime pharmacotherapeutic target for addiction and cardiometabolic disease. Our prior biophy...
Versatility of Particulate Carriers: Development of Pharmacodynamically Optimized Drug-Loaded Microparticles for Treatment of Peritoneal Cancer
Intraperitoneal (IP) chemotherapy confers significant survival benefits in cancer patients. However, several problems, including local toxicity and ineffectiveness against bulky tumors, have prohibited it from becoming a...
Mass Spectrometry Screening Reveals Peptides Modulated Differentially in the Medial Prefrontal Cortex of Rats with Disparate Initial Sensitivity to Cocaine
The online version of this article (doi:10.1208/s12248-010-9204-2) contains supplementary material, which is available to authorized users.