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Biomedical subjects

N G Pearson

Publications and source records attributed to N G Pearson.

8 recordsLinked to original sources
PubMed2000

Influence of peroxide impurities in povidone and crospovidone on the stability of raloxifene hydrochloride in tablets: identification and control of an oxidative degradation product.

The purpose of this study was to identify a degradation product in a tablet formulation of raloxifene hydrochloride (R-HCl), delineate the role of excipients in its formation, and develop a rational strategy for its control. The degradant was identified as an N-oxide derivative of the drug substance based upon spectroscopic characterization and chromatographic comparison to the synthetic N-oxide. To identify the factors contributing to the formation of N-oxide, binary mixtures of each excipient with R-HCl were exposed to 125 degrees C in open containers. Raloxifene hydrochloride underwent an order of magnitude increase in conversion to the N-oxide in the presence of two excipients, povidone and crospovidone, as compared with its conversion in the presence of other excipients. To confirm a hypothesis that peroxide impurities in these two excipients contributed to the oxidation of the drug substance, tablet lots were spiked with quantities of H2O2 equivalent to 200, 400, 600, and 800 ppm peroxide over the intrinsic levels present in povidone and crospovidone. A strong correlation was observed between the total peroxide level and the quantity of the N-oxide formed upon accelerated storage. From these experiments a rational limit test for peroxide content in povidone and crospovidone was adopted as part of a control strategy to limit formation of the degradation product.

Drug Contamination↗
PubMed1976

Myocardial infarction: a comparison between home and hospital care for patients.

To compare the results of home and hospital treatment in men aged under 70 years who had suffered acute myocardial infarction within 48 hours 1895 patients were considered for study in four centres in south-west England. Four-hundred-and-fifty patients were randomly allocated to receive care either at home by their family doctor or in hospital, initially in an intensive care unit. The randomised treatment groups were similar in age, history of cardiovascular disease, and incidence of hypotension when first examined. They were followed up for up to a year after onset. The mortality rate at 28 days was 12% for the random home group and 14% for the random hospital group; the corresponding figures at 330 days were 20% and 27%. On average, older patients and those without initial hypotension fared rather better under home care. The patients who underwent randomisation were similar to those whose place of care was not randomised, except that the non-randomised group contained a higher proportion of initially hypotensive patients, whose prognosis was poor wherever treated. These results confirm and extend our preliminary findings. Home care is a proper form of treatment for many patients with acute myocardial infarction, particularly those over 60 years and those with an uncomplicated attack seen by general practitioners.

Adult↗
PubMed1971

Acute myocardial infarction: home and hospital treatment.

This is a preliminary report of a co-operative study of 1,203 episodes of acute myocardial infarction in men under 70 years in four centres in the south west of England. The mortality at 28 days was 15%. A comparison is made between home care by the family doctor and hospital treatment initially in an intensive care unit: 343 cases were allocated at random. The randomized groups do not differ significantly in composition with respect to age; past history of angina, infarction, or hypertension; or hypotension when first examined. The mortality rates of the random groups are similar for home and hospital treatment. The group sent electively to hospital contained a higher proportion of initially hypotensive patients whose prognosis was bad wherever treated; those who were not hypotensive fared rather worse in hospital.For some patients with acute myocardial infarction seen by their general practitioner home care is ethically justified, and the need for general admission to hospital should be reconsidered.

Acute Disease↗
PubMed1970

Analysis of an open electrocardiograph referral service for family doctors.

The results of a questionary to investigate an open electrocardiograph (E.C.G.) service for family doctors suggest that the service is useful in diagnosis (26% of the E.C.G. reports were unexpected) and in management (the result of the E.C.G. led to specific treatment or alteration to regimen in 22% of cases and in a further 46% to reassurance). The results suggest that during the 45 weeks of the study many outpatient appointments were avoided.Undoubtedly an open E.C.G. service allows the family doctor to give a quicker and better service to his patients. For this reason and because of operational benefits to the hospital the service must be recommended.

Diagnosis, Differential↗