No abstract

In vitro results are presented for a novel oral drug-delivery system ultimately intended for treatment of oral infections in immunocompromised patients. Test samples of ethylene vinyl acetate copolymer (EVA) containing chlorhexidine diacetate (CDA) showed desirable antimicrobial properties and steady, slow release into aqueous and other media after an initial burst of drug release in the first day of liquid exposure. By washing away this initial burst, the proposed mouthguard device should be capable of sustained delivery of locally effective CDA concentrations far below systemically toxic levels. A prolonged room temperature shelf-life of at least 1 year, and effectivity against a wide range of oral bacteria and Candida species was demonstrated. Drug loaded films showed a top-to-bottom asymmetry in drug release, but good lateral homogeneity, and a linear relationship between initial CDA loading concentration (from 0.63 to 10 wt %) and days 3-14 release rates in a static aqueous environment. The EVA matrix containing CDA appears to possess many suitable properties for localized oral delivery of sustained antimicrobial activity.

No abstract

The paper introduces a simple method to synthesize novel liquid crystalline polystyrene (LC-PS) containing a mesogenic unit at a side chain by hydrosilylation through poly[(4-vinylphenyl)dimethylsilanol] (PVPDMS) and liquid crystal monomer cholesteryl 4-[4-(undec-10-enoyloxy)benzoyloxy]phenyladipate (M). The LC-PS had high purity, high molecular weight, narrow distribution, good thermal stability, and typical thermotropic liquid crystallinity (SA phase), as shown by 1H NMR analyses, size exclusion chromatography (SEC), thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X-ray diffraction (XRD). The glass-transition temperature (Tg) of LC-PS was much lower than that of PVPDMS, while the clearing point (Ti) of LC-PS significantly increased compared with M.