Design and evaluation of dental films of PEGylated rosin derivatives containing sparfloxacin for periodontitis.

OBJECTIVE: In this study, PEGylated rosin derivatives (PRDs) namely D1 and D2 were synthesized and evaluated for their application to produce sustained-release antibacterial films containing sparfloxacin for periodontitis. SIGNIFICANCE: PRDs are biodegradable and biocompatible, and therefore sustained-release dental implant of PRD-sparfloxacin can provide an effectual treatment for periodontitis. METHODS: Films were produced by solvent casting technique and characterized for morphology, swelling-index, in vitro degradation and drug release kinetics. The impact of type of PRD, concentration of PRDs, and addition of plasticizer (dibutyl phthalate) on various film properties was evaluated. The films were also subjected to stability study at 30 °C and 40 °C for 90 days. RESULTS: Both D1 and D2 produced smooth and non-porous films with sparfloxacin. The D1 films, due to lower amount of polyethylene glycol 400 in D1, exhibited lower swelling-index, slower degradation, and slower drug release compared to D2 films. An increase in PRDs concentration decreased swelling-index, prolonged degradation time, and decreased drug release rate of films; addition of plasticizer showed the similar effect. At pH 7.6, D1 and D2 films showed complete degradation at the end of 58 and 51 days, respectively. At the end of 21 days, D1 and D2 films released 41.85% and 61.53% sparfloxacin, respectively. The drug release from D1 films followed Higuchi square-root kinetics, while D2 films released drug by the zero order kinetics. The stability conditions did not significantly alter PRDs-film properties. CONCLUSION: Results revealed that PRDs can be used successfully to produce sustained-release antibacterial films containing sparfloxacin for the treatment of periodontitis.

Evaluation of gum mastic (Pistacia lentiscus) as a microencapsulating and matrix forming material for sustained drug release.

In this study, a natural gum mastic was evaluated as a microencapsulating and matrix-forming material for sustained drug release. Mastic was characterized for its physicochemical properties. Microparticles were prepared by oil-in-oil solvent evaporation method. Matrix tablets were prepared by wet and melt granulation techniques. Diclofenac sodium (DFS) and diltiazem hydrochloride (DLTZ) were used as model drugs. Mastic produced discrete and spherical microspheres with DLTZ and microcapsules with DFS. Particle size and drug loading of microparticles was in the range of 22-62 µm and 50-87%, respectively. Increase in mastic: drug ratio increased microparticle size, improved drug loading and decreased the drug release rate. Microparticles with gum: drug ratio of 2:1 could sustain DLTZ release up to 12 h and released 57% DFS in 12 h. Mastic produced tablets with acceptable pharmacotechnical properties. A 30% w/w of mastic in tablet could sustain DLTZ release for 5 h from wet granulation, and DFS release for 8 h and 11 h from wet and melt granulation, respectively. Results revealed that a natural gum mastic can be used successfully to formulate matrix tablets and microparticles for sustained drug release.

Sustained release microspheres of diclofenac sodium using PEGylated rosin derivatives.

The PEGylated derivatives of rosin-PD-1 and PD-2 synthesized and characterized earlier (Nande et al., 2006) were investigated as potential materials for sustained release microsphere prepared by emulsion solvent evaporation method using diclofenac sodium (DCS) as model drug. All the microspheres exhibited smooth surfaces intercepted by pores; their sizes (d(90)) ranged between 11-24 microm. The entrapment efficiency (< 80%) of the microspheres increased proportionally with derivative concentration. Presence of solvent like isopropyl alcohol or dichloromethane rendered the microspheres with large sizes but with reduced drug entrapment. Microspheres with small size were obtained at an optimum viscosity of liquid paraffin; any change lead to increase in the particle size. Magnesium stearate was found to be most suitable detackifier in the present system. The drug release was directly related to the particle size--small sized microspheres released drug at a faster rate. The dissolution data complied with Higuchi equation while the mechanism of drug release was Fickian diffusion (n approximately 0.5). Controlled inhibition of edema, as tested by hind paw edema method, was observed for 10 h when the microspheres were administered intraperitoneally. The present study found the derivatives as promising materials for preparing microspheres for sustained delivery of DCS.

PEGylated rosin derivatives: novel microencapsulating materials for sustained drug delivery.

The aim of this study was to investigate PEGylated rosin derivatives (PRDs) as microencapsulating materials for sustained drug delivery. PRDs (D1, D2, and D3) composed of a constant weight of rosin and varied amounts of polyethylene glycol (PEG) 400 and maleic anhydride were synthesized in the laboratory. Microparticles were prepared by the O/O solvent evaporation technique using the acetone/paraffin system. Diclofenac sodium (DFS) and diltiazem hydrochloride (DLTZ) were used as model drugs. The effect of the type of PRD, drug, PRD:drug ratio, viscosity of external phase, stirring speed, concentration of magnesium stearate (droplet stabilizer), and method of preparation on particle size, drug loading, and drug release profiles of microparticles was investigated. PRDs could produce discrete and spherical microspheres (with DFS) and microcapsules (with DLTZ). The drug loading value for microparticles was found to be in the range of 37.21% to 87.90%. The microparticle size range was 14 to 36 microm. The particle size and drug loadings of microparticles were substantially affected by the concentration of magnesium stearate and the type of drug, respectively. Most of the formulations could sustain the DFS and DLTZ release for 20 hours. DFS and DLTZ release from PRD microparticles followed Hixson-Crowell and first-order kinetics, respectively. The results suggest that PRDs can be used successfully to prepare discrete and spherical microparticles with DFS and DLTZ for sustained drug delivery.