Outcomes of a Survey-Based Approach to Determine Factors Contributing to the Shortage of Occupational Medicine Physicians in the United States.

CONTEXT: There is a long-standing shortage of formally trained Occupational & Environmental Medicine (OEM) physicians despite OEM practitioners experiencing high satisfaction and low burnout. OBJECTIVE: To explore the root causes of this shortage and suggest potential remedies. METHODS: Cross-sectional surveys were administered to medical students queried regarding OEM training, practicing OEM physicians queried regarding timing of specialty choice, and OEM Train-in-Place (TIP) program graduates queried regarding satisfaction with training. RESULTS: Of 247 medical student respondents, 70% had heard of OEM, 60% through one lecture. Of the 160 OEM physicians, 17% first became aware of OEM as medical students, and most would have chosen a different path had they heard sooner. Most TIP program trainees reported that they would not have undertaken specialty training without a TIP program (89%). CONCLUSIONS: Strategies to introduce OEM earlier in medical education and TIP programs for mid-career physicians may help overcome persistent shortages of OEM specialists.

Factorial design in the spheronization of ibuprofen microparticulates using the rotor disk fluid-bed technology.

The aim of this study was to statistically evaluate the effects of some formulation and process variables in the spheronization of microparticulates of ibuprofen using the rotor disk fluid-bed technology and water as binder. Preliminary studies revealed that presence of surfactant, plate material type, and nature and content of binder influenced the process and quality of the spheronized material. A 2 x 2 x 3 full factorial randomized experiment was designed, demonstrating the influence of these factors on properties such as percent yield, particle size distribution, densities, ibuprofen release, moisture content, etc., as well as their interactions in the experimental response. A response known as the usable fraction was created representing microparticulates of 250 to 850 microm sizes (mesh size 20-60). The reproducibility of the spheronization process was assessed by blocking the experiments with the experiments within the blocks randomly replicated. The main effects included two binder levels (X1), two surfactant levels (X2), and a three-level plate type (X3) in which 2 two-level factors were collapsed into a single three-level factor. The results from the statistical analysis (general linear model, JMP 4) showed that the variables studied had a significant influence on most of the response variables evaluated (p < 0.05), with the binder level proving to be the most significant of the three. There was also significant interaction (p<0.05) between binder level and plate type with the drug content, friability, sphericity, loss on drying (LOD), and usable fraction response variables, and between the binder and the surfactant levels with the drug content, Q20, true density, geometric mean diameter, LOD, and usable fraction responses. High levels of surfactant and binder increased the sphere size, while low levels decreased it. Significant (p < 0.05) interaction was also observed between the plate type and surfactant level with the drug content, geometric mean diameter, and more or less with Q20 and bulk density response variables. Blocking of the experiments had no significant effect on the process and product characteristics analyzed, indicating the reproducibility of the process.

Feasibility studies in spheronization and scale-up of ibuprofen microparticulates using the rotor disk fluid-bed technology.

The aim of this study was to develop spheronized microparticulates as a drug delivery system using the 1-step closed rotor disk fluid-bed technology, and to scale up the batch spheronization process. Ibuprofen was used as the model drug and microcrystalline cellulose/sodium carboxymethyl cellulose hydrocolloid (Avicel(R) RC-581 or CL-611) was present as the diluent/binder. The mixture, in 1:1 ratio, was blended with and without 1% sodium lauryl sulfate (SLS) and spheronized with the rotor disk insert, using either water or hydroxypropylmethyl cellulose (HPMC) as binder. Fluid-bed machines (Vector/Freund Flo-Coater model) FLM-1 (with 9-inch rotor insert for 0.75 kg) and FLM-15 (with a 12-inch and 19-inch rotor inserts for 1 kg and 5, 10 kg, respectively) were used. The critical process parameters included inlet air temperature, rotor disk speed and configuration, air flow, and rate of binder application. The 1 kg batch containing SLS that was made with 12-inch smooth stainless steel or waffle teflon plates rotating at 500 rpm had desirable characteristics. The sphericity values were 0.88 and 0.91, with percent yield of 85.4 and 91.2 and drug content values of 94.47% and 91.44%, respectively. The spheroids showed good flow properties with respective rapid drug release (Q20 = 83.27 and 91.75). No difference was seen in the Avicel RC-581 and CL-611. Based on the 1 kg data, Avicel RC-581 and smooth stainless steel and waffle teflon plates (12 inch and 19 inch), the batch was scaled up to 5 and 10 kg. The scale-up parameters included rotor speed (124 -300 rpm) and spray rate (90-140 g/min). The scale-up batches had similar flow characteristics, release rate, and size distribution. The geometric mean diameter increased as batch size increased, and slightly bigger spheroids were obtained using the waffle teflon plate. Ibuprofen spheres with very good physical characteristics were developed using the rotor disk fluid-bed technology, a 1-step closed process that did not require additional unit processes.