Abstract:
Background: Template directed synthesis of Layered double hydroxides (LDH) has gained much
attention as the removal of the template results in a porous LDH material with large surface area
which leads to high drug loading.
Objectives: To synthesize Mg-Al LDHs via template-directed synthesis using different aging
conditions followed by calcination, to load prepared LDH samples with diclofenac sodium and to
compare drug loading capacities of these composites
Methods: Templated Mg Al LDHs (TLDH1, TLDH2) were synthesized using sodium dodecyl
sulphate (SDS) and poly vinyl pyrrolidone (PVP). TLDH1 was aged at 60°C in an oven for 20 h
and TLDH2 was aged at 135 °C for 4 h hydrothermally in an autoclave. Samples were calcined at
500°C for 5 h to remove the template and the LDH structure was regenerated using an ethanolic
solution of diclofenac sodium (TLDH1-R-D, TLDH2-R-D). Corresponding pristine LDL samples
were synthesized following the same procedure without the template (LDH1, LDH2). Prepared
LDHs were characterized using x-ray diffraction (XRD), fourier transform infrared spectroscopy
(FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) techniques.
Drug loading capacities of prepared LDHs were analysed.
Results: The XRD spectra of prepared LDHs exhibited characteristic diffraction peaks
corresponding to (003), (006), (009), (015), (018), (110), and (113) planes revealing a successful
synthesis of pure LDH layers. Changing the reaction conditions resulted in the Mg-Al LDHs with
different degrees of crystallinity and crystal size. Samples prepared via PVP-SDS template
method showed high drug loading, compared to corresponding pristine LDH samples. Moreover,
the drug loading capacity of TLDH2-R-D, showed higher drug loading capacity (51.3%)
compared to TLDH1-R-D (41.9%).
Conclusions: Mg-Al LDH nanocarriers having high drug loading capacity could be successfully
synthesized using PVP-SDS template. Drug loading capacity could be increased by aging the
samples hydrothermally (135°C).
Keywords: Drug loading, Layered double hydroxides, Poly Vinyl Pyrrolidone, Sodium Dodecyl
Sulphate, Template
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