Background:
Controlled oral dosage forms have always been preferred for drugs with variable absorption, and
short biological half life and frequent dosing. The prime goal with sustained release systems is to maintain uniform
therapeutic blood levels for longer periods of time. Interpenetrating networks (IPNs) have been evidenced as uniform
sustained release systems. In current study, polyvinyl alcohol (PVA) and locust bean gum (LBG) based IPNs were
developed for the oral sustained release drug delivery of gliclazide (shows variable absorption).
Method:
The IPNs were synthesized by emulsion cross-linking method using glutaraldehyde (GA) as a cross linking agent.
Gliclazide is a potential second generation, short-acting sulfonylurea oral hypoglycemic agent is having a short biological
half-life (2-4 h), variable absorption and poor oral bioavailability. Various batches of IPNs were formulated by varying
LBG: PVA ratio and evaluated for percentage yield, drug entrapment efficiency (DEE), swelling properties and in vitro
drug release studies. Further characterizations were done by Fourier Transform Infrared Spectroscopy (FTIR), C13 Solid
state NMR, X-Ray diffraction study (XRD), Scanning electron microscopy (SEM), and Differential scanning microscopy
(DSC) studies.
Results:
The percentage yield, drug entrapment and equilibrium swelling was observed to be dependent on PVA-LBG ratio
and GA amount. Sustained release of drug was observed in all IPN formulations (approx 59 - 86% in 8 h in various
batches) with variable release kinetics. SEM studies revealed the regular structures of IPNs. FTIR, XRD, C13 Solid state
NMR and DSC studies proposed that drug was successfully incorporated into the formed IPNs.
Conclusion:
IPNs of LBG and PVA can be used as a promising carrier with uniform sustained release characteristics.