A novel method for the detection of sticking of tablets.

The purpose of this work was to develop an instrumented upper punch to measure the adhesion force which occurs when the punch detaches itself from the upper surface of the tablet after compression. A specially designed adhesion force sensor instrumented with semiconductor strain gauges was inserted into an upper punch with a 25-mm punch face diameter suitable for a Korsch EK II eccentric press. Sorbitol, microencapsulated acetylsalicylic acid (ASA), and a formulation of a new active ingredient resulted in characteristic pull-off signals, providing a quantitative measure of the adhesion force. With "sticking-free" substances such as microcrystalline cellulose, tension signals could not be obtained; only Starch 1500 showed small adhesion force signals that indicated a sticking tendency. The compression force had a specific influence on the extent of the adhesion force; increasing the compression force caused an increase (sorbitol) or a decrease (ASA) of the adhesion force signals due to the plastic and elastic behavior of the substances. Depending on running time, ASA showed an increase in the adhesion force, reaching a plateau after 150 tablets. The addition of lubricants such as magnesium stearate resulted in smaller adhesion forces. The instrumented upper punch is a new helpful tool for the quantification of sticking and a valuable instrument in the development of formulations.

The influence of engravings on the sticking of tablets. Investigations with an instrumented upper punch.

The purpose of this study was to investigate the influence of engravings on the sticking of tablets. Therefore, an instrumented upper punch capable of measuring the pull-off force, which occurs when the punch detaches itself from the upper surface of a tablet, was equipped with small cones of different angles between the punch face and the cones' lateral face. The cones could be screwed into a threaded hole at the center of the punch face. The adhesion forces of two formulations known to stick to engravings during production increased with a greater steepness of the cones' lateral face. With microencapsulated acetylsalicylic acid, no quantitative differences could be found between the adhesion forces obtained with plain and modified punch faces, indicating that the sticking behavior of the substance was not affected by shear forces. Starch 1500 showed higher adhesion force signals in comparison to those obtained with a plain punch face. Microcrystalline cellulose, which gave no adhesion force signals with a plain punch face and did not stick to the cones, showed distinct pull-off signals. The instrumented upper punch equipped with shear cones is a valuable instrument for detecting the adhesion caused by engravings and is therefore a helpful tool for tablet formulation development and the design optimization of tablet identification.

A randomized, controlled trial of the efficacy of a heparin and vancomycin solution in preventing central venous catheter infections in children.

OBJECTIVE: To determine whether adding vancomycin to central venous catheter (CVC) flush solution would significantly reduce the incidence of bacteremia attributable to luminal colonization with vancomycin-susceptible organisms. STUDY DESIGN: Fifty-five children with cancer and eight children given total parenteral nutrition by the surgery or nutrition support services were randomly assigned to receive a heparin CVC flush solution (n = 31) or a heparin-vancomycin CVC flush solution (n = 32). RESULTS: During 9158 catheter days, 6.5% of the patients in the heparin group and 15.6% of the patients in the heparin-vancomycin group had bacteremia attributable to luminal colonization with vancomycin-susceptible organisms (p = 0.43). The mean rates of bacteremia attributable to luminal colonization with vancomycin-susceptible organisms were 0.6/1000 catheter days in the heparin group and 1.4/1000 catheter days in the heparin-vancomycin group (p = 0.25). There was no significant difference between the groups when the time to the first episode of bacteremia attributable to luminal colonization with a vancomycin-susceptible organism was compared by means of Kaplan-Meier survival estimates. Streptococcus viridans infection was not attributable to luminal colonization. CONCLUSION: The addition of vancomycin to heparin CVC flush solution did not reduce bacteremia with vancomycin-susceptible organisms. Bacteremia with Streptococcus viridans was not related to the use of a CVC.

A prospective, controlled evaluation of home chemotherapy for children with cancer.

OBJECTIVES: Infusion of chemotherapy at home provides an alternative to hospitalization for children with cancer. Few programs of pediatric home chemotherapy have been described or evaluated. The purpose of this work was to compare prospectively chemotherapy in the hospital to chemotherapy at home with respect to billed medical charges, out-of-pocket expenses, and quality of life. METHODS: Eligibility criteria for home therapy were defined. Parents and nurses were trained. Billed charges, loss of wages, out-of-pocket expenses, medical outcome, and quality of life of 14 patients for one course of chemotherapy in the hospital were compared with those for an identical course at home. RESULTS: Daily charges for chemotherapy were $2329 +/- 627 in the hospital and $1865 +/- 833 at home; out-of-pocket costs, $68 +/- 31 and $11 +/- 6, respectively; and loss of income, $265 +/- 233 and $67 +/- 107, respectively. Patients' independence, well-being, appetite, mood, and school work were significantly better at home, and parental time at work and with the family was greater. CONCLUSION: Administration of selected chemotherapy at home results in lower billed charges, reduced expenses, reduced loss of income for parents, and a more satisfying lifestyle for patients and parents.

The night stalker effect: quality improvements with a dedicated night-call rotation.

RATIONALE AND OBJECTIVES: The authors assessed whether a non-sleep-deprived, second-year diagnostic radiology resident assigned to an after-hours "night stalker" emergency radiology (ER) rotation in an urban university hospital has a measurable impact on the number and clinical significance of "missed" radiologic findings. METHODS: After-hours Emergency Department (ED) radiographs interpreted by radiology residents between January and December 1991 were reviewed daily by ER faculty. Faculty-modified final interpretations were recorded on a worksheet and given to the attending ED physician (EDP). The EDP reviewed and, if indicated, modified clinical dispositions, and categorized missed diagnoses as requiring recall into the following categories: 1 = immediately, 2 = in 24 to 48 hours, 3 = no recall necessary, or 4 = recognized during patient visit by clinicians. Morbidity attributable to "misses" was graded A to C (A, definite; B, possible; C, none). All cases requiring patient recall were evaluated monthly with follow-up information and classified as false-positive, false-negative, or indeterminant. The relative performance of control (traditional "call") and night stalker groups were compared. RESULTS: Of 26,421 on-call examinations in 1991, there were 489 (1.1%) misses, of which 202 (1.4%) were from the June-to-December study group. The control group residents averaged 2.75 hours of sleep per call night. On night stalker days, on-call residents and the night stalker averaged 5.75 and 7.25 hours of sleep daily, respectively. The fractions (and number) of recall assignments of discordant cases for the control and night stalker groups, respectively, were: 1) immediate 48% (23) and 26% (32); 2) within 48 hours 31% (15) and 26% (31); 3) no recall 79% (38) and 36% (43); and, 4) abnormality not missed by EDPs 10% (5) and 12% (15). Morbidity for the control and night stalker groups, respectively, were: 1) 4% and 0%; 2) 31% and 30%; and 3) 65% and 70%. The amount of rework between July and December 1991 spent by the EDPs to re-evaluate cases because of discordant opinions was more than 68 hours, with no significant difference noted between the study groups. Errors were false-negative, 84.9% (415); false-positive, 7% (34); and indeterminant, 8.2% (40). Radiology faculty errors contributed 5.8% (13) of patient recalls (false-positive, 11; false-negative, 2). Finally, 58/78 questionnaire respondents believed that service quality had improved. No one believed that the standard of service had been lowered. CONCLUSIONS: A dedicated night-shift ER coverage of a busy urban ED improves quality, appropriateness, and timeliness of patient care.