Nicotine (NCT), administered in the form of a fast dissolving oral delivery system, can be a potential alternative to nicotine replacement therapy. NCT was extracted by maceration and acid-base extraction methods from Burley tobacco leaves with different stalk positions and extraction yield and NCT content were further determined. The extract with the highest nicotine content was selected for incorporation into a fast dissolving film formulation. The optimized film was evaluated for its physical and mechanical properties, in vitro disintegration, and drug release profile. The results demonstrated that the extract from the upper part of tobacco leaves using the acid-base extraction method had the highest amount of NCT. NCT fast dissolving film consisting of this extract as the active ingredient and HPMC E15 as a film polymer resulted in a homogeneous translucent film with a light brown color. The addition of NCT significantly affected the film properties in terms of weight, disintegration time, tensile strength, percentage elongation at break, and Young’s modulus values. The drug release of NCT fast dissolving film showed a rapid initial release of 80% within three minutes, and its kinetics followed the Higuchi matrix model. The results suggest that these NCT films can be employed in the development of NCT fast dissolving films for clinical use.

Carbamide peroxide (CP) possesses a strong tooth bleaching activity, however, its clinical application is limited because of its instability in aqueous formulations. This study explores the improvement of CP stability and bleaching activity by loading CP in electrospun nanofibrous film (ENF). Polyvinylalcohol, polyvinylpyrrolidone, and silica were used as components for core-based nanofibers of ENF. Electrospinning feed aqueous solutions (EFASs) were developed for preparing CP loaded ENF (CP-ENF). Stability of CP in EFASs is significantly higher than in pure water. The highest stability of CP is found in PPS-CP3, composed of 0.5% CP, 5.5% polyvinylalcohol, 3% polyvinylpyrrolidone, and 1% silica. The results from X-ray diffraction indicate that CP is dispersed as a non-crystalline form in CP-ENFs. CP and the compositions of EFASs play a major role on characteristics and bleaching efficiency of CP-ENFs. Drug release of CP-ENFs is the first order kinetics. CP-ENF obtained from PPS-CP3 shows the highest drug entrapment efficiency, high adhesion, and suitable sustained release. Drug release mechanism is along with anomalous transport according to Korsmeyer–Peppas model. In an ex vivo study using human teeth, it shows the highest bleaching efficiency among the others. Therefore, CP-ENF obtained from PPS-CP3 is a promising ENF for clinical use.

The effects of variety and modification of rice on its antioxidant and anti-inflammatory activities were investigated. White rice varieties; Jasmine (JM) and Saohai (SH), and pigmented rice varieties; Doisket (DS) and Homnil (HN) were used. The modified rice samples were obtained from chemical modification using etherification reaction. The activities of the modified rice samples were compared with the ethanol extracts of the raw rice at the same rice concentration. Antioxidant activity was measured by the free radical scavenging activity tests and ferric reducing power assay. Results indicated that the ethanol extracts of raw rice had higher antioxidant activity than the modified rice. Among the raw rice tested, the pigmented rice showed higher antioxidant activity than white rice. Trolox equivalent antioxidant capacity values from free radical scavenging activity test were revealed that 50% ethanol extracts of HN and DS possessed the highest antioxidant activity. Ferric reducing power assay showed that 50% ethanol extracts of DS had the highest antioxidant activity. The anti-inflammatory activity was evaluated in vitro using a lipopolysaccharide-stimulated RAW264.7 macrophage cell model with enzyme-linked immunosorbent assay. Absolute ethanol extracts of HN reduced interleukin-6 secretion whereas that of DS suppressed interleukin-6 and tumor necrosis factor -α secretion. These results indicate that variety of rice, chemical modification, and extracting solvent were the factors that play an important role on antioxidant and anti-inflammatory activity. This study supports the potential use of the pigmented rice, especially DS, as a promising choice of a natural source because of its antioxidant and anti-inflammatory activities.

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