Abstract:
Lyotropic liquid crystals (LC) having amphiphilic properties are promising materials as co-surfactants
in emulsion formulations. A carbohydrate lyotropic liquid crystal, hexadecyl-β-D-glucopyranoside, was
synthesized by linking D-glucose to cetyl alcohol via acetylated glucoside and its ability to stabilize
microemulsions was investigated. The synthesized compound was characterized by using Nuclear Magnetic
Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Both acetylated and
deacetylated compounds were found to exhibit thermotropic and lyotropic liquid crystal behaviour. The
critical micelle concentration (CMC) value of 1.53 × 10−5 mol dm−3 obtained for hexadecyl-β-Dglucopyranoside
from both UV-visible spectroscopic and turbidity methods suggests its non-ionic
surfactant properties. Calculated HLB value of 8.86 indicates that it is suitable for making self-emulsifying
oils and water in oil (W/O) emulsions.
ME systems were prepared using Olive oil, water and the nonionic lipophilic surfactant Sorbitan
monooleate (Span 80) by selecting suitable compositions of both W/O (water in oil) and O/W (Oil in Water)
emulsion systems from the phase diagram constructed at 70 °C. By introducing optimum amount of
0.05 wt.% of synthesized glycolipid, macro emulsions formulated was successfully converted into
microemulsions. Then, hydrophilic drug, Diclofenac sodium (DS) (1.00% (w/w)) was introduced to the
selected W/O and O/W emulsions separately and in vitro release of drugs through a pig ear (ear epidermis)
fitted to a Franz diffusion cell system was observed with and without glycolipid (hexadecyl-β-Dglucopyranoside)
(0.05% (w/w)) as permeation enhancer. Aqueous solution of DS (1% (w/w)) was used as
the control.
The optimized ME formulations which contain DS as model drug show higher amount of release of
76.35% and 63.52% for W/O and O/W respectively. Those systems exhibit 6-10 nm nano-scaled aggregates
which improve the permeation and its large surface area enhances the quick release of both sparingly
soluble and highly soluble drugs in water. Finally, it is clearly understand that incorporating hexadecyl-β-D
glucopyranoside in ME formulations shows significant potential as a delivery vehicle in the cosmetics and
pharmaceutical industry.
