Influence of hydration state and homologue composition of magnesium stearate on the physical chemical properties of liquid paraffin lipogels

K. A. Sheikh, Y. B. Kang, J. J. Rouse, G. M. Eccleston

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Lipogels were prepared by dispersing mixed (60:40 C(16)-C(18)) and pure (C(18)) homologue magnesium stearate (MgSt) in liquid paraffin, using three methods of preparation, i.e. addition of water at 95 degrees C during cooling cycle (method 1), homogenisation upon cooling (method 2) or cooling without addition of water or homogenisation (method 3). The systems were characterised by physical inspection, polarised, hot stage and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and X-ray diffraction (XRD). Systems formed stable semisolid lipogels (no syneresis), unstable solids showing syneresis or structured fluids, depending on the type of magnesium stearate used and the preparation technique. The stable semisolid lipogels containing mixed homologue MgSt (commercial-as received, anhydrous or dihydrate) prepared by methods 1 (similar to 1-2% water) and 2 contained alpha-crystalline lamellar structure. These were not present in the unstable solids formed with method 3 or in systems prepared from pure homologue MgSt which were generally structured fluids rather than semisolids. In addition, semisolid lipogels of pure homologue trihydrate MgSt prepared by method 3 showed plate-like crystals, implying pressure sensitivity. There is significantly more amorphous MgSt in the unstable solids compared to the stable semisolid lipogels, which are mainly crystalline (confirmed by XRD).
Original languageEnglish
Pages (from-to)121-127
Number of pages7
JournalInternational Journal of Pharmaceutics
Volume411
Issue number1-2
DOIs
Publication statusPublished - 15 Jun 2011

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Mineral Oil
X-Ray Diffraction
Water
Rheology
Differential Scanning Calorimetry
stearic acid
Electron Scanning Microscopy
Pressure

Keywords

  • acid
  • aluminium soaps
  • creams
  • surfactants
  • alcohols
  • maltese crosses
  • gelation
  • magnesium stearate
  • rheology
  • lipogels
  • base
  • pseudopolymorph
  • liquid paraffin
  • micelles
  • hydrocarbons
  • alpha-crystalline lamellar structure
  • influence
  • hydrations state
  • homologue composition
  • physical chemical properties

Cite this

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title = "Influence of hydration state and homologue composition of magnesium stearate on the physical chemical properties of liquid paraffin lipogels",
abstract = "Lipogels were prepared by dispersing mixed (60:40 C(16)-C(18)) and pure (C(18)) homologue magnesium stearate (MgSt) in liquid paraffin, using three methods of preparation, i.e. addition of water at 95 degrees C during cooling cycle (method 1), homogenisation upon cooling (method 2) or cooling without addition of water or homogenisation (method 3). The systems were characterised by physical inspection, polarised, hot stage and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and X-ray diffraction (XRD). Systems formed stable semisolid lipogels (no syneresis), unstable solids showing syneresis or structured fluids, depending on the type of magnesium stearate used and the preparation technique. The stable semisolid lipogels containing mixed homologue MgSt (commercial-as received, anhydrous or dihydrate) prepared by methods 1 (similar to 1-2{\%} water) and 2 contained alpha-crystalline lamellar structure. These were not present in the unstable solids formed with method 3 or in systems prepared from pure homologue MgSt which were generally structured fluids rather than semisolids. In addition, semisolid lipogels of pure homologue trihydrate MgSt prepared by method 3 showed plate-like crystals, implying pressure sensitivity. There is significantly more amorphous MgSt in the unstable solids compared to the stable semisolid lipogels, which are mainly crystalline (confirmed by XRD).",
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year = "2011",
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Influence of hydration state and homologue composition of magnesium stearate on the physical chemical properties of liquid paraffin lipogels. / Sheikh, K. A.; Kang, Y. B.; Rouse, J. J.; Eccleston, G. M.

In: International Journal of Pharmaceutics, Vol. 411, No. 1-2, 15.06.2011, p. 121-127.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Influence of hydration state and homologue composition of magnesium stearate on the physical chemical properties of liquid paraffin lipogels

AU - Sheikh, K. A.

AU - Kang, Y. B.

AU - Rouse, J. J.

AU - Eccleston, G. M.

PY - 2011/6/15

Y1 - 2011/6/15

N2 - Lipogels were prepared by dispersing mixed (60:40 C(16)-C(18)) and pure (C(18)) homologue magnesium stearate (MgSt) in liquid paraffin, using three methods of preparation, i.e. addition of water at 95 degrees C during cooling cycle (method 1), homogenisation upon cooling (method 2) or cooling without addition of water or homogenisation (method 3). The systems were characterised by physical inspection, polarised, hot stage and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and X-ray diffraction (XRD). Systems formed stable semisolid lipogels (no syneresis), unstable solids showing syneresis or structured fluids, depending on the type of magnesium stearate used and the preparation technique. The stable semisolid lipogels containing mixed homologue MgSt (commercial-as received, anhydrous or dihydrate) prepared by methods 1 (similar to 1-2% water) and 2 contained alpha-crystalline lamellar structure. These were not present in the unstable solids formed with method 3 or in systems prepared from pure homologue MgSt which were generally structured fluids rather than semisolids. In addition, semisolid lipogels of pure homologue trihydrate MgSt prepared by method 3 showed plate-like crystals, implying pressure sensitivity. There is significantly more amorphous MgSt in the unstable solids compared to the stable semisolid lipogels, which are mainly crystalline (confirmed by XRD).

AB - Lipogels were prepared by dispersing mixed (60:40 C(16)-C(18)) and pure (C(18)) homologue magnesium stearate (MgSt) in liquid paraffin, using three methods of preparation, i.e. addition of water at 95 degrees C during cooling cycle (method 1), homogenisation upon cooling (method 2) or cooling without addition of water or homogenisation (method 3). The systems were characterised by physical inspection, polarised, hot stage and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and X-ray diffraction (XRD). Systems formed stable semisolid lipogels (no syneresis), unstable solids showing syneresis or structured fluids, depending on the type of magnesium stearate used and the preparation technique. The stable semisolid lipogels containing mixed homologue MgSt (commercial-as received, anhydrous or dihydrate) prepared by methods 1 (similar to 1-2% water) and 2 contained alpha-crystalline lamellar structure. These were not present in the unstable solids formed with method 3 or in systems prepared from pure homologue MgSt which were generally structured fluids rather than semisolids. In addition, semisolid lipogels of pure homologue trihydrate MgSt prepared by method 3 showed plate-like crystals, implying pressure sensitivity. There is significantly more amorphous MgSt in the unstable solids compared to the stable semisolid lipogels, which are mainly crystalline (confirmed by XRD).

KW - acid

KW - aluminium soaps

KW - creams

KW - surfactants

KW - alcohols

KW - maltese crosses

KW - gelation

KW - magnesium stearate

KW - rheology

KW - lipogels

KW - base

KW - pseudopolymorph

KW - liquid paraffin

KW - micelles

KW - hydrocarbons

KW - alpha-crystalline lamellar structure

KW - influence

KW - hydrations state

KW - homologue composition

KW - physical chemical properties

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U2 - 10.1016/j.ijpharm.2011.03.052

DO - 10.1016/j.ijpharm.2011.03.052

M3 - Article

VL - 411

SP - 121

EP - 127

JO - International Journal of Pharmaceutics

JF - International Journal of Pharmaceutics

SN - 0378-5173

IS - 1-2

ER -