In recent years,
attention has shifted toward the utilization
of
natural polymers for encapsulation and sustained release of health-hazardous
drugs. The purpose of this work is to define and assess the sustained
delivery potential and mucoadhesive potential of a Cydonia oblonga mucilage (COM) and sodium alginate
(Na-Alg)-constituting polymeric delivery carrier of antidiabetic drugs
with a specific end goal to retain metformin HCl in the stomach while
expanding the drug’s bioavailability. Metformin HCl was encapsulated
in mucoadhesive microspheres by an ionic gelation method. Polymers
with different combinations were tried, and the resulting mucoadhesive
COM/Na-Alg microspheres were assessed for particle size (mm) PS/Y1, drug encapsulation efficiency DEE (%)/Y2, and in vitro percentage cumulative drug release R12h/Y3 using Drug Design Expert software version 10. The
response surface methodology by a 32-central composite
design predicted optimal synthesis parameters for the microspheres
to be 295 mg for COM and 219 mg for Na-Alg. An optimized formulation
was prepared under these conditions and used to evaluate the micrometric
properties, morphology and structural characteristics, swelling behavior, in vitro drug release, and kinetics. Acute toxicity studies
were carried out on blank COM/Na-Alg microspheres to deem them safe
for in vivo studies. The DEE (%) was calculated to
be 85.8 ± 1.67, whereas scanning electron microscopy (SEM) showed
a coarse surface with characteristic wrinkles and cracks with an optical
microscopic particle size of 0.96 ± 2.45. The ex vivo tests showed great mucoadhesive properties and good swelling behavior
with pH-responsive drug release and a significant reduction in in vivo blood glucose levels. The results advocated the
use of optimized microspheres to enhance the bioactivity with a possible
dose reduction, making it less symptomatic, reducing the expense of
the treatment, and subsequently facilitating better patient compliance.