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

Musculoskeletal pain among surgeons performing minimally invasive surgery: a systematic review

BACKGROUND: Musculoskeletal pain is the most common occupational disease in Europe. Surgeons with awkward and static working postures are no exception. Robotic-assisted laparoscopy has been postulated to be superior to conventional laparoscopy regarding the ergonomic strain for surgeons. In this review, we aimed to systematically evaluate the existing literature comparing the two surgical modalities.METHODS: A systematic literature search was employed in PubMed, Embase and Cochrane Library in spring 2015. Inclusion criteria were as follows: English language, full text available, original data, and comparative data on surgeons' physical workload with robotic-assisted laparoscopy and conventional laparoscopy. Studies only describing a single surgical modality were excluded. We applied the checklist, STrengthening the Reporting of OBservational studies in Epidemiology (STROBE), to assess the quality of reporting of the included studies. Semi-quantitative comparisons were made.RESULTS: In total, 2685 records were screened and 15 articles were included in the analysis. All studies were observational with sample sizes ranging from one single surgeon to 250 questionnaire responses. None of the studies fully fulfilled the criteria of STROBE, with an average score of 13 (range 10-16) out of 18.DISCUSSION: Results, mainly self-reported measures, suggest that robotic-assisted laparoscopy is less strenuous compared with conventional laparoscopy. However, results are limited by the large methodological heterogeneity and a high risk of bias. We advocate for further high-quality exposure studies to assess the potential ergonomic deficits related to different minimally invasive surgical techniques. In addition, future intervention studies should evaluate possible means to alleviate and prevent musculoskeletal pain among surgeons.</p