Formulation and characterization of norethisterone transdermal patch as an alternative route to oral administration

Purpose : To design a transdermal norethisterone (NE) patch for controlled drug release Methods : Polymers, viz, sodium salt of carboxymethyl cellulose (CMCNa) and hydroxyethyl cellulose (HEC), as well as a plasticizer (propylene glycole, PG) were used at various ratios to prepare NE films. The drug was dispersed in water and mixed with the polymer gel/plasticizer mixture prior to film casting. Weight variation, thickness, tensile strength, and the interaction between drug and film excipient were evaluated. The films were also characterized by Fourier transform infrared spectroscopy (FT–IR). In vitro drug dissolution and release from the transdermal patches (coded C–L, C–T, H–L and H–T) were evaluated. Results : There was significant difference between the batches in terms of in vitro drug release (p > 0.05). Dissolved drug was significantly higher in H-T film when compared to C-L film (p < 0.05). In addition, drug release was significantly higher from H-T patch than from C-L patch (p < 0.05). Conclusion: NE transdermal patches containing HEC and Transcutol® have been successfully formulated. They can potentially be used to deliver NE via transdermal route to decrease the side effects associated with the oral route of administration of the hormone. Keywords : Norethisterone, Transdermal delivery, Controlled release, Hormone therapy