Rapid titrimetric and spectrophotometric determination of ofloxacin in pharmaceuticals using N-bromosuccinimide / Determinação titulométrico e espectrofotométrico rápido de ofloxacina em produtos farmacêuticos usando N -bromosuccinimida

One titrimetric and two spectrophotometric methods have been described for the determination of ofloxacin (OFX) in bulk drug and in tablets, employing N-Bromosuccinimide as an analytical reagent. The proposed methods involve the addition of a known excess of NBS to OFX in acid medium, followed by determination of unreacted NBS. In titrimetry, the unreacted NBS is determined iodometrically, and in spectrophotometry, unreacted NBS is determined by reacting with a fixed amount of either indigo carmine (Method A) or metanil yellow (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of OFX. Titrimetry allows the determination of 1-8 mg of OFX and the calculations are based on a 1:5 (OFX:NBS) reaction stoichiometry. In spectrophotometry, Beer's law is obeyed in the concentration ranges 0.5-5.0 µg/mL for method A and 0.3-3.0 µg/mL for method B. The molar absorptivities are calculated to be 5.53x10(4) and 9.24x10(4) L/mol/cm for method A and method B, respectively. The methods developed were applied to the assay of OFX in tablets, and results compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via the standard-addition method.

Descrevem-se métodos, um titulométrico e dois espectrofotométricos, para a determinação de ofloxacino (OFX) na matéria-prima e em comprimidos, empregando a N-bromossuccinimida (NBS) como reagente analítico. Os métodos propostos envolvem a adição de excesso conhecido de NBS ao OFX, em meio ácido, seguida de determinação do NBS que não reagiu. Na titulometria, o NBS que não reagiu é determinado iodometricamente e na espectrofotometria, o NBS que não reagiu é determinado pela reação com quantidade fixa de índigo carmim (Método A) ou amarelo de metanila (Método B). Em todos os métodos, a quantidade de NBS que reagiu corresponde à quantidade de OFX. A titulometria permite a determinação de 1-8 mg de OFX e os cálculos se baseiam na estequiometria de reação de 1:5 (OFX:NBS). Na espectrofotometria, a Lei de Beer é obedecida nas faixas de concentração de 0,5-5,0 µg/mL, para o método A, e de 0,3-3,0 µg/mL, para o método B, respectivamente. Os métodos desenvolvidos foram aplicados para o teste de OFX em comprimidos e os resultados foram comparados estatisticamente com aqueles do método de referência. A precisão e a confiabilidade dos métodos foram, posteriormente, verificadas por meio dos testes de recuperação via método de adição de padrão.

Evaluating Antibiotic Use in a Secondary Level Hospital Neonatal Unit in the Western Cape; South Africa

Abstract:Perinatal infection significantly contributes to neonatal morbidity and mortality. There are no reliable rapid diagnostic tests. Drug resistance is increasing in organisms acquired in hospital. There are little data on the indications for antibiotic use and the prevalent organisms in lower resource settings; and none in regional hospitals in South Africa. We conducted a retrospective cohort study of risk factors; indications for and drugs used at Worcester Provincial Hospital Neonatal Unit. A systematic sample of every alternate neonate listed in the admissions register from 1 July 2005 to 30 June 2006 was taken. Charts for all cases were reviewed. Early antibiotic use was defined as therapy within 72 hours of life. One hundred and ninetyfive infants where included; 144 (74) had 194 antibiotic events. Antibiotic events occurred at a rate of 99 events per 100 neonates. Prematurity was common (83 of admissions) and; in conjunction with prolonged rupture of membranes; was the major driver of early antibiotic use. Ceftriaxone use within 72 hours of birth was significantly associated with subsequent antibiotic events; compared with penicillin alone or in combination with an aminoglycoside (p 0.04). Longer duration of treatment for early events was associated with subsequent empiric need for antibiotics (p 0.02). Prematurity is the major driver for antibiotic use at this unit. Antibiotics are prescribed appropriately but earlier discontinuation; which may be complicated by the inability to confirm/refute infection; should be practised. Alternatives to third generation cephalosporins should be available to treat hospital infection at secondary level

Bartonella bacilliformis: acción in vitro de la cloromicetina sobre la Bartonella bacilliformis / Bartonella bacilliformis: action in vitro of chloromycetin on Bartonella bacilliformis

Se ha estudiado la acción in-vitro de la Cloromicetina sobre la Bartonella bacilliformis, y se encuentra que ella inhibe el desarrollo de dicho germen. Primero: a la dosis de 3.9 gammas por cc. Después de 48 horas de contacto del germen con el antibiótico. Dosis menores de la señalada no ejerce acción inhibidora aún 72 horas después. Dosis mayores, como 31.2 gammas por cc. Actúa en forma inmediata, y 15.6 gammas por cc., 24 horas después de estar en contacto el germen con el antibiótico. Segundo: no se observa alteraciones en la morfología de la Bartonella bacilliformis por acción del antibiótico. De todo lo cual se deduce que la Cloromicetina debe resultar de gran valor en el tratamiento de la Enfermedad de Carrión.

The in vitro action of Chloromycetin (Chloramphenicol) on Bartonella bacilliformis was studied, disclosing the following: 1. Bartonella bacilliformis was inhibited by a threshold concentration of 3.9 gammas/cc. after 48 hours of contact with antibiotic. 2. No morphological changes were observed on B. bacilliformis under action of the antibiotic. These studies suggest that Chloromycetin might be a great value in the treatment of Carrion’s Disease.

Costs of antibiotic therapy

An increasing number of new and expensive antibiotics on the market makes it imperative that costs be contained and an attempt made to rationalise use without comprising patient care. Prerequisites of any containment programme are education of health and medical personnel and a good communication system to provide timely reports on culture and sensitivity results to personnel concerned

Problems of antibiotic use

Antibiotics are among the most widely used of all therapeutic agents and it is almost certainly true that they are over prescribed, both in hospitals and in the community. The evidence indicates that a good knowledge of medical microbiology among general practitioners correlates well with low prescription rates. In addition, use of the laboratory and consultation with a microbiologist has been shown to improve the rational prescribing antimicrobial chemotherapy. This short essay looks at four problems associated with antimicrobial therapy: toxicity, interactions of antibiotics with other drugs, resistance of micro-organism to antibiotics and superinfection following administration of antibiotics