In Vitro and in Vivo Evaluation of Whole and Half Tablets of Sustained-Release Adinazolam Mesylate

The mechanism of release from sustained-release adinazolam mesylate tablets was assessed by the Higuchi equation and by analysis of drug release profiles through 60% released using the Peppas equation. Computed values of the diffusional exponent, n, ranged from 0.59 to 0.66. Values of n in this range are consistent with a mixed mechanism of release, with diffusion of drug through the hydrated polymer matrix and relaxation of this matrix being the principal processes controlling release. The rate of in vitro drug release was increased for half tablets relative to whole tablets and is attributed to an increase in the surface to volume ratio of half tablets of about 16%. This increase in surface-to-volume ratio of half tablets was reflected by an increase in the constant, k, from the Peppas equation of 20–23% and by an increase in the slope of Higuchi plots of 12–18% for four lots of tablets. In vivo/in vitro relationships from two bioavailability studies were thoroughly evaluated. Using either a linear or a quadratic relationship, an in vivo/in vitro correlation exists for sustained-release adinazolam mesylate tablets.     

Oxford Handbook of Pre-hospital Care

There are at least two reasons why this Oxford handbook meritsa review in the British Journal of Anaesthesia. A proportionof readers will be involved at some time during their careerin the provision of pre-hospital care and most of us will onoccasion manage patients on their arrival in hospital followingcare for acute medical and surgical problems in the community.The Oxford series aims to act as a succinct primer in each subject,and this one succeeds. The contents page illustrates its     

Evidence of sustained skeletal benefits from impact-loading exercise in young females: a 3-year longitudinal study.

The skeletal effects from intensive exercise throughout puberty are undefined. Forty-five female gymnasts and 52 controls were studied over 3 years, including a heredity aspect. The effects of size, maturity, exercise, and diet were identified using a multilevel regression model. Results demonstrated sustained skeletal benefits resulting from exercise throughout all stages of pubertal development. INTRODUCTION: Weight-bearing exercise is beneficial for peak bone mass development. However, whether skeletal benefits achieved with exercise are maintained if training remains intensive throughout the pubertal years is not entirely clear. The influence of familial resemblance for bone mass remains undefined in physically active versus inactive children. The aim of this study was to investigate the long-term influences of impact-loading exercise on bone quantity and quality in young females after controlling for growth, maturation, and hereditary factors. MATERIALS AND METHODS: At baseline, 45 gymnasts (G) and 52 normally active controls (C) 8-17 years of age were recruited. Anthropometry, diet, physical activity, and quantitative ultrasound (QUS) were measured annually for 3 consecutive years. DXA scans of total body (TB) and lumbar spine (LS) bone mineral content (BMC) and density (BMD) were taken three times at 1-year intervals. A multilevel regression model was fitted, and the independent effects of body size, maturity, physical activity, and diet were identified over time. To assess heredity influences, 27 G mothers and 26 C mothers volunteered for cross-sectional measurements of anthropometry, QUS, and BMC/BMD. RESULTS AND CONCLUSIONS: Gymnasts were smaller and lighter (as were their mothers) than controls, but they had significantly higher QUS and axial and appendicular BMC and BMD, with > 170 g more bone mineral in TB across puberty (after adjustment for maturity [years from peak height velocity], height, weight, energy, and protein intake). Gymnasts had up to 24-51% higher BMC and 13-28% higher BMD, depending on skeletal site. These results provide evidence of sustained skeletal benefits from impact-loading exercise, which are unlikely to result entirely from heredity, throughout pubertal years.     

The Washington University-Barnes Hospital experience with lung transplantation. Washington University Lung Transplantation Group

OBJECTIVE.--To review our experience with lung transplantation, emphasizing recipient selection, choice of procedure, functional results, and outcome. DESIGN.--Retrospective review of patients who received lung transplants at Barnes Hospital, St Louis, Mo, between July 1, 1988, and January 31, 1991. SETTING.--Washington University School of Medicine, St Louis, Mo, and Barnes Hospital, a medical school and its affiliated referral hospital, respectively. PATIENTS.--Sixty-nine lung transplant procedures were performed in 66 recipients. Patients with clinically and physiologically severe lung disease were selected according to predetermined guidelines. Underlying diseases in the recipients included chronic obstructive pulmonary disease, alpha 1-antitrypsin deficiency emphysema, cystic fibrosis, pulmonary fibrosis, primary pulmonary hypertension, Eisenmenger's syndrome associated with an atrial septal defect, bronchiectasis, eosinophilic granuloma, and lymphangiomyomatosis. INTERVENTION.--Double-lung, bilateral sequential, and single-lung transplantations were performed. Eight patients underwent en bloc double-lung transplantations or a modification of this procedure with separate bronchial anastomoses. Thereafter, the bilateral sequential approach to replacement of both lungs was performed in 26 patients. Thirty-two patients underwent single-lung transplantations. MAIN OUTCOME MEASURES.--Pulmonary function tests, arterial blood gas levels, pulmonary artery pressure, pulmonary vascular resistance, and actuarial survival. RESULTS.--Actuarial survival at 1 year for the 66 lung transplant recipients was 79%. Actuarial survival at 1 year was 82% for the bilateral lung transplant recipients and was 90% for the single-lung transplant recipients. In patients with either restrictive or obstructive lung disease, pulmonary function tests and arterial blood gas levels improved markedly after lung transplantation. In patients with primary pulmonary hypertension or Eisenmenger's syndrome, the pulmonary artery pressure decreased and the cardiac index increased into the normal range after single-lung transplantation. CONCLUSIONS.--In carefully selected patients with end-stage lung disease, single-lung and bilateral lung transplantations can significantly improve functional capacity, with promising early actuarial survival statistics after 1 year.     

Early pharmacokinetics and clinical effects of oral D-amphetamine in normal subjects

Seven normal subjects received 0.25 mg/kg D-amphetamine orally, both after an overnight fast and again after a standard breakfast. Plasma levels, subjective and cardiovascular effects, and observer-rated activation were assessed hourly for 5 hr. Food did not affect amphetamine levels. Plasma levels peaked at 2-3 hr. Maximum cardiovascular effects generally occurred at 1 hr, whereas maximum behavioral and subjective effects occurred at 2 hr. Subjective and behavioral effects declined thereafter, in spite of substantial amphetamine levels. A separate group of 8 subjects received 0.5 mg/kg D-amphetamine orally. Plasma levels, subjective and cardiovascular effects, and activation ratings were assessed hourly for 4 hr. Maximum plasma levels were approximately twice those seen in the first group. In this case, plasma levels peaked at 3-4 hr; blood pressure and subjective and behavioral effects were all maximal at 2-3 hr and were declining by 4 hr, in spite of stable or rising plasma levels.