Abstract:
This paper explores the potential of polyethylene glycol enclatherated pectin-mucin (PEGencl-
PEC:MUC) submicron matrices (SMMs) as an intravaginal drug delivery system
capable of delivering an anti-HIV-1 agent (zidovudine; AZT) over a prolonged duration. A
three factor and three level (33) Box-Behnken statistical design was employed to optimize
the SMMs. Optimized PEG-encl-PEC:MUC SMMs prepared as a stable W/O emulsion
(determined by the degree of reversible colloidal phenomena) were spherical with a mean
particle size of 270.6±5.533nm and mean zeta potential of -34.4±0.539mV. The
microencapsulation of AZT and the hydrogen bonding mediated shielding of AZT by SMMs
was confirmed by Fourier Transform Infrared (FTIR) analysis. The thermochemical
(differential scanning calorimetry and thermogravimetric analysis) data proposed that Ca2+-
based macromolecular ionic crosslinking as well as the intermolecular interactions may be
responsible for the thermal stability of the delivery system. The partially amorphous nature of
drug-loaded SMMs, as confirmed by X-ray diffraction patterns, further strengthened the
matricization of AZT into the pectin-mucin matrix. In vitro drug release studies from the
SMMs showed approximately 91% zidovudine release in simulated vaginal fluid (SVF) and
94% in phosphate buffered saline (PBS) in 24 hours. The mean dissolution time (MDT) of
zidovudine from the SMMs was 5.974 hours. The attainment of required dimensional
structure and drug release profiles from SMMs highlights the potential of their inclusion into a
secondary carrier system for extended and controlled intravaginal stay.
