A STUDY ON SOME TRANSDERMAL DRUG DELIVERY SYSTEMS

Abstract

In this chapter we have studied the effect of different factors that could affect NF stability in solution form (pH, temperature, light of different intensities and drug concentration ). Of all these factors, NF has proved to be affected only by light. Trials have been adapted to stabilize NF solution on exposure to light using different light absorbers (colorants) namely tartrazine, curcumine and FD&C yellow #6.Also the effect of an antioxidant (BI-IT) in three concentration levels was studied . NF solution showed better stability on using FD&C yellow #6 and tartrazine than curcumine.The effect of the concentration of the first two colorants has been also investigated, where it was found that increasing the colorant concentration ( from I to 5 mg%w/v) showed an improvement of drug stability. On the other hand, using BHT alone showed no significant effect on solution stability even at its highest concentration (10 mg%w/v). Combining BHT with either of tartrazine or FD&C has shown better stabilizing effect on NF solution than the antioxidant alone with the two combinations showing almost the same effect. The FD&C/BHT combination has been chosen to stabilize NF gels (Carbopol-940 and PVA) and films (PYA) under stress storage conditions and light exposure.