In-vitro and in-vivo evaluation of formulated lidocaine dental gels and ointments

ABSTRACT

In this research, lidocaine HCl and lidocaine were formulated on different gel and ointment bases. Eight formulations of lidocaine and lidocaine HCl ointment and gel [four as 2% gel, one as 5% gel and three as 5% ointment] were prepared and tested for their release in Sorensen's phosphate buffer pH 7.4 using USP dissolution test apparatus at 37C +/- 0.5C and compared with four commercially available products; namely, xylocaine 2% jelly, xylonor 5% gel, xylocaine 5% ointment [Astra, Sweden] and xylocaine 5% ointment [Astra, Cid]. In vitro results showed that formula I [lidocaine HCl 2.0 g in carbopol gel base] and formula IV [lidocaine HCl 2.0 g in carboxymethyl cellulose gel base] gave the highest extent of release of the prepared gel formulae. Formula VII [lidocaine 5 g in emulsifying ointment base containing liquid paraffin and bees wax] gave the highest extent of release among all the prepared ointment formulae. The local anesthetic effect of the prepared lidocaine gel and ointment was evaluated in vivo using albino mice