This study was designed to evaluate different polymers to their
suitability for formulation as vehicles for topical delivery system.
Meloxicam (MX) was incorporated into the gel vehicles in a
concentration of 1.0% w/w. It is a non-steroidal anti-inflammatory
drug (NSAID) of the enolic acid class of compounds.
Polymers used in this study are methylcellulose (MC), tylose
(Ty), polyvinyl alcohol (PVA), poloxamer 407 (polo), polyethylene glycol (PEG), carbopol 974P (Carb. and eudispert mv. (Eud). They
are used in a suitable concentration for gel formation.
In-vitro release characteristics of the drug from different gels
were carried out using dialysis membrane in phosphate buffer pH
6.8. The release data were treated with various kinetic principles to
assess the relevant parameters.
The general rank order of MX release was MC > Ty > polo >
PVA > other gel forms. The results also showed that, the release of
drug from the prepared gels obeyed the diffusion model (Higuchi's
equation).
The influence of some formulation and processing variables
(initial drug concentration of 0.5, 1.0 and 2.0% w/w, poloxamer
407 concentration of 20, 25, 30% w/v in the aqueous gel
formulation) on the release patterns have been studied. The results
revealed an inverse correlation between the drug release rate and
the poloxamer 407 concentration and direct correlation between
the drug release rate and the initial drug concentration.
The anti-inflammatory activity of the drug in different gel
formulations was studied using carrageenan induced rat paw
edema method. The results obtained show an excellent antiinflammatory
activity on rat paw edema.