The development of direct extrusion-injection moulded zein matrices as novel oral controlled drug delivery systems

Purpose: To evaluate the potential of zein as a sole excipient for controlled release formulations prepared by hot melt extrusion. Methods: Physical mixtures of zein, water and crystalline paracetamol were hot melt extruded (HME) at 80°C and injection moulded (IM) into caplet forms. HME-IM Caplets were characterised using differential scanning calorimetry, ATR-FTIR spectroscopy, scanning electron microscopy and powder X-ray diffraction. Hydration and drug release kinetics of the caplets were investigated and fitted to a diffusion model. Results: For the formulations with lower drug loadings, the drug was found to be in the non-crystalline state, while for the ones with higher drug loadings paracetamol is mostly crystalline. Release was found to be largely independent of drug loading but strongly dependent upon device dimensions, and predominately governed by a Fickian diffusion mechanism, while the hydration kinetics shows the features of Case II diffusion. Conclusions: In this study a prototype controlled release caplet formulation using zein as the sole excipient was successfully prepared using direct HME-IM processing. The results demonstrated the unique advantage of the hot melt extruded zein formulations on the tuneability of drug release rate by alternating the device dimensions

Initial experience of a novel ergonomic surgical chair for laparoscopic pelvic surgery

INTRODUCTION: We present the initial experience of a novel surgical chair for laparoscopic pelvic surgery, the ETHOS TM (Bridge City Surgical, Portland, OR). MATERIALS AND METHODS: The ETHOS chair has an adjustable saddle height that ranges from 0.89 to 1.22 m high, an overall width of 0.89 m, and a depth of 0.97 m. The open straddle is 0.53 m and fits most OR tables. We performed 7 pelvic laparoscopy cases with the 1st generation ETHOS TM platform including 2 laparoscopic ureteral reimplantations, 5 laparoscopic pelvic lymphadenectomies for staging prostate cancer in which one case involved a laparoscopic radical retropubic prostatectomy, performed by 2 different surgeons. RESULTS: All 7 pelvic laparoscopic procedures were successful with the ETHOS TM chair. No conversion to open surgery was necessary. Survey done by surgeons after the procedures revealed minimal stress on back or upper extremities by the surgeons from these operations even when surgery was longer than 120 minutes. Conversely, the surgical assistants still had issues with their positions since they were on either sides of the patient stressing their positions during the procedure. CONCLUSION:The ETHOS chair system allows the surgeon to operate seated in comfortable position with ergonomic chest, arms, and back supports. These supports minimize surgeon fatigue and discomfort during pelvic laparoscopic procedures even when these procedures are longer than 120 minutes without consequence to the patient safety or detrimental effects to the surgical team

Encapsulation of Hydrophilic and Lipophilic Compounds in Nanosomes Produced with a Supercritical Based Process

Liposomes are created when phospholipids self-assemble in an aqueous medium creating spherical closed structures. These vesicles can be loaded with hydrophilic active principles (AP) into the aqueous inner core or with lipophilic compounds in the lipidic double layer. In this work a new supercritical based process for the one-step continuous production of nanosomes is proposed for the encapsulation of hydrophilic and lipophilic compounds. This process is called Supercritical Assisted Liposome Formation (SuperLip). The innovation of this process consists in the inversion of the traditional phases of production of liposomes: water droplets are created by a spray atomization in a high pressure vessel, and then a double layer of phospholipids fast surrounds them. A systematic study on liposome size, morphology, encapsulation efficiency has been performed for several different hydrophilic AP (ampicillin, ofloxacin, bovine serum albumin, fluorescein, eugenol and theophylline). Some operative parameters were also optimized to achieve the production of nanometric liposomes with high encapsulation efficiencies. Operating in this way nanometric and monodispersed liposome suspensions were produced with EE up to 99%. To complete the study, other lipidic compounds were entrapped in the double lipidic layer, obtaining high entrapment efficiencies (TE), also in this case, up to 84.9%