Some considerations about the hydrophilic–lipophilic balance system

Amphiphilic block copolymers tend to self-assemble in an aqueous phase and form micelles. These polymeric micelles have nanoscale, high thermodynamic and kinetic stability and can solubilize hydrophobic substances; therefore, they may be applied to separation systems, drug delivery systems, pharmaceuticals, or emulsion stabilization (1-3). Polymeric micelles composed of block copolymers show a core-shell micellar structure with a hydrophobic inner core surrounded by a hydrated outer shell in aqueous solution. Hydrophobic drugs can be incorporated into the hydrophobic inner core and the hydrated outer shell helps prevent opsonization of the carrier and uptake by the reticu- The objective of this work was to study the effect of fatty acid chain length grafted to methoxy poly(ethylene glycol) (mPEG) on self assembling properties of micelles for etoposide delivery. Three amphiphilic copolymers were synthesized using mPEG, myristic acid, stearic acid and behenic acid through an esteric linkage. The particle size and zeta potential of the micelles were determined by the dynamic light scattering method. Etoposide was loaded into micelles by film casting using various drug/polymer ratios. Drug release was studied by the dialysis method. The structure of copolymers was confirmed by 1 H NMR and FTIR. Central micellar concentration (CMC) measurements showed that the longer hydrophobic chains formed more thermodynamically stable micelles. Among the prepared copolymers, etoposide showed the highest solubility in the mPEG-behenic copolymer. Drug loading efficiency depended on the hydrophobic chain length and drug/polymer ratio. The highest drug loading efficiency was found in mPEG-myristic micelles with 1:20 drug/polymer ratio. Micelles released 80 % of loaded drug within about 5 h.

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“…The HLB value of copolymers was measured using the relative molecular mass of mPEG-fatty acid conjugates as reported by Pasquali et al (15).…”

Section: Hydrophilic-lipophilic Balance (Hlb) Values Of the Mpeg-fattmentioning

confidence: 99%

Optimization of self-assembling properties of fatty acids grafted to methoxy poly(ethylene glycol) as nanocarriers for etoposide

Varshosaz¹,

Hasanzadeh²,

Eslamdoost³

2012

Acta Pharmaceutica

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“…1. Due to its amphiphilic properties CH can serve as a cosurfactant [29]. It was previously reported that CH acts as coemulsifier in W/O emulsions and in reversed micelles [29][30][31][32].…”

Section: Ch-loaded Microemulsion Systemsmentioning

confidence: 99%

Competitive solubilization of cholesterol and phytosterols in nonionic microemulsions studied by pulse gradient spin-echo NMR

Rozner

Aserin

Garti

2008

Journal of Colloid and Interface Science

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“…The HLB was developed as an empirical scale where oleic acid and its salt, sodium oleate were used as standards with values of 1 and 20 respectively, and other compounds (analytes) were compared and placed accordingly on this scale. It has, however, been argued lately that the HLB approach only gives approximate values since some arbitrary scale is deployed and the values obtained in the original experiments by Griffin are not experimental but rather calculated from theoretical formulae [10].…”

Section: Introductionmentioning

confidence: 99%

The Study of a Simple Pine-Oil Based Laboratory Prepared and Commercial Detergents Using Conductivity Measurements

George¹,

Motsamai²

2015

AJAC

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Detergents are very important substances in everyday life as they are used in laundry services. This manuscript reports the study of the commercial and laboratory prepared pine oil-based detergents employing the critical micelle concentration (CMC) phenomenon using conductivity measurements. The two samples showed the CMC values of 0.0725 g/cm 3 and 0.0920 g/cm 3 for laboratory and commercial samples respectively. The effect of ionic strength was investigated using NaCl and it demonstrated a drop of CMC value of about CMC by 40% (laboratory sample) and 70% (commercial sample) while the equi-molar naphthalene increased the CMC values by about 50% (laboratory sample) and 12% (commercial sample) relative to their corresponding values under distilled water. The combined effect of equi-molar NaCl and naphthalene lowered the CMC by 5% (laboratory sample) and 30% (commercial sample). These differences could signify the superiority of the laboratory sample in that it is somehow buffered against drastic changes in the CMC under different conditions. The relationship between conductivity and the CMC values does not show sufficient linearity (R 2 < 0.8403) suggesting different mechanisms of interactions between NaCl and naphthalene. Overall, the results are gratifying to the small-scale manufacturer who supplied the preparation protocol for laboratory sample preparation, in two respects: they inspire some degree of confidence in his product as well as enabling the manufacturer to employ the same protocol for his quality control practices as such improve product consistency and hence profitability.

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Some considerations about the hydrophilic–lipophilic balance system

Cited by 166 publications

References 1 publication

Optimization of self-assembling properties of fatty acids grafted to methoxy poly(ethylene glycol) as nanocarriers for etoposide

Optimization of self-assembling properties of fatty acids grafted to methoxy poly(ethylene glycol) as nanocarriers for etoposide

Competitive solubilization of cholesterol and phytosterols in nonionic microemulsions studied by pulse gradient spin-echo NMR

The Study of a Simple Pine-Oil Based Laboratory Prepared and Commercial Detergents Using Conductivity Measurements

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