Acute and Sub-Acute Toxicity of Dichloromethane-Methanol Root Bark Extract of Teclea trichocarpa Engl. (Rutaceae) in Rats

The in vivo toxicity profile of dichloromethane-methanol (50:50 % v/v) extract of Teclea trichocarpa Engl. (Rutaceae) root bark using Wister rats is reported. No death occurred in the oral acute and sub-acute toxicity studies. In the acute intraperitoneal test, all the animals at 2000 mg/kg developed convulsions followed by death within 3 min; at 300 mg/kg, death occurred within 4-48 h, but there was no death at 50 mg/kg. In the acute oral, subacute oral and 50 mg/kg acute intraperitoneal tests, all haematological and biochemistry parameters fluctuated but remained within normal limits, suggesting that T. trichocarpa root bark extract is practically non-toxic and supports the safety of this plant as a traditional herbal remedy. However, toxicity of the extract on intraperitoneal administration requires further study.Key words: Teclea trichocarpa, root bark extract, acute toxicity, sub-acute toxicit

Drug Quality Control in Kenya: Observation in Drug Analysis and Research Unit during the Period 1996-2000

The Drug Analysis and Research Unit received and analyzed 261 drug samples over a five-year period, 1996 to 2000. Samples were received from regulatory authorities, local industry, non-governmental organizations, hospitals and private practitioners. The samples analyzed constituted 59.8 % locally manufactured and 40.2 % imported products. The overall rate of failure to comply with quality specifications set out in the respective monographs was 21.1 %. This represents 24.6 % and 16.2 % of the locally manufactured and imported drugs, respectively. Key Words: Quality control, active pharmaceutical ingredient content, dissolution. East and Central African Journal of Pharmaceutical Sciences Vol.5(2) 2002: 28-3

Liquid chromatographic analysis of phenobarbitone, ethosuximide, phenytoin and carbamazepine on a polystyrene-divinyl benzene column

A liquid chromatographic method for the simultaneous assay of four anticonvulsant drugs, phenobarbitone, ethosuximide, phenytoin and carbamazepine on a polystyrene-divinyl benzene column is described. The method was developed by the systematic study of different types of co-polymer materials, type and concentration of organic modifiers, buffer pH and concentration and column temperature. A PLRP-S 100 Å 8 µm column maintained at 60 oC and a mobile phase consisting of acetonitrile-tert-butanol-phosphate buffer (pH 7.6, 0.2 M)-water (25:5:10:60, v/v) were used. The flow rate was 1 ml/min with ultraviolet detection at 220 nm. The method has been validated and used for the analysis of raw materials, finished products and dissolution studies of the drugs. Keywords: Liquid chromatography, co-polymer column, phenobarbitone, ethosuximide, phenytoin, carbamazepine. The East and Central African Journal of Pharmaceutical Sciences Vol. 8 (3) 2005: pp 19-2

Evidence review of hydroxyurea for the prevention of sickle cell complications in low-income countries.

Hydroxyurea is widely used in high-income countries for the management of sickle cell disease (SCD) in children. In Kenyan clinical guidelines, hydroxyurea is only recommended for adults with SCD. Yet many deaths from SCD occur in early childhood, deaths that might be prevented by an effective, disease modifying intervention. The aim of this review was to summarise the available evidence on the efficacy, effectiveness and safety of hydroxyurea in the management of SCD in children below 5 years of age to support guideline development in Kenya. We undertook a systematic review and used the Grading of Recommendations Assessment, Development and Evaluation system to appraise the quality of identified evidence. Overall, available evidence from 1 systematic review (n=26 studies), 2 randomised controlled trials (n=354 children), 14 observational studies and 2 National Institute of Health reports suggest that hydroxyurea may be associated with improved fetal haemoglobin levels, reduced rates of hospitalisation, reduced episodes of acute chest syndrome and decreased frequency of pain events in children with SCD. However, it is associated with adverse events (eg, neutropenia) when high to maximum tolerated doses are used. Evidence is lacking on whether hydroxyurea improves survival if given to young children. Majority of the included studies were of low quality and mainly from high-income countries. Overall, available limited evidence suggests that hydroxyurea may improve morbidity and haematological outcomes in SCD in children aged below 5 years and appears safe in settings able to provide consistent haematological monitoring

Liquid chromatographic separation of hexopyranosylated cytosine nucleosides from their degradation products

Development of a liquid chromatographic method which can separate each of a series of hexopyranosylated cytosine nucleosides from their degradation products formed at acid, neutral and basic pH is described. Both silica-based reverse-phase and polymer columns were examined. Influence of the mobile phase pH, ion-pairing agent, concentration of the buffer and type and concentration of organic modifier were systematically investigated. The concentration of the ion-pairing agent and the buffer were found to have a major effect on selectivity. Samples were finally analyzed on a poly(styrene-divinylbenzene), PLRP-S 100 Angstrom (8 mu m) 250 x 4.6 mm I.D. column at 60 degrees C and with a mobile phase consisting of acetonitrile-sodium octanesulphonate (pH 2.5; 0.02 M)-potassium phosphate buffer (pH 2.5; 0.2 M)-water (X:25:50:25 -X, v/v, where X is variable). (C) 1997 Elsevier Science B.V

Evidence review of hydroxyurea for the prevention of sickle cell complications in low-income countries

Hydroxyurea is widely used in high-income countries for the management of sickle cell disease (SCD) in children. In Kenyan clinical guidelines, hydroxyurea is only recommended for adults with SCD. Yet many deaths from SCD occur in early childhood, deaths that might be prevented by an effective, disease modifying intervention. The aim of this review was to summarise the available evidence on the efficacy, effectiveness and safety of hydroxyurea in the management of SCD in children below 5 years of age to support guideline development in Kenya. We undertook a systematic review and used the Grading of Recommendations Assessment, Development and Evaluation system to appraise the quality of identified evidence. Overall, available evidence from 1 systematic review (n=26 studies), 2 randomised controlled trials (n=354 children), 14 observational studies and 2 National Institute of Health reports suggest that hydroxyurea may be associated with improved fetal haemoglobin levels, reduced rates of hospitalisation, reduced episodes of acute chest syndrome and decreased frequency of pain events in children with SCD. However, it is associated with adverse events (eg, neutropenia) when high to maximum tolerated doses are used. Evidence is lacking on whether hydroxyurea improves survival if given to young children. Majority of the included studies were of low quality and mainly from high-income countries. Overall, available limited evidence suggests that hydroxyurea may improve morbidity and haematological outcomes in SCD in children aged below 5 years and appears safe in settings able to provide consistent haematological monitoring

Triterpenoids from the stem bark of Blighia unijugata bak. (sapindaceae)

Two pentacyclic triterpenoids were isolated, for the first time, from the stem bark of Blighia unijugata Bak. The structures of the two compounds were elucidated on the basis of their spectral data as friedelin and epifriedelinol.Keywords: triterpenoid, stem bark, Blighia unijugata, friedelin, epifriedelino

Liquid-chromatographic separation of diamino analogs of 2'-deoxyadenosine or 3'-deoxyadenosine from adenine on a poly(styrene-divinylbenzene) polymer column

A liquid chromatographic method that can separate each of a series of diamino analogues of 2'- or 3'-deoxyadenosine from their main degradation product, adenine, is described. A PLRP-S 1000 Angstrom (8 mu m) 250 mm x 4.6 mm I.D. column was used at 60 degrees C. The method was developed by systematic evaluation of the influence of the mobile phase pH, the type and concentration of the organic modifier, the concentration of the ion-pairing agent and the buffer. The mobile phase consisted of tetrahydrofuran-0.2 M sodium octanesulphonate-0.2 M potassium phosphate buffer (pH 2.0)-water (15:25:30:30, v/v).status: publishe

Evaluation of the kinetics of hydrolysis of monoamino analogs of 2'-deoxyadenosine or 3'-deoxyadenosine and of 9-(2-deoxy-beta-D-threo-pentofuranosyl)adenine or 9-(3-deoxy-beta-D-threo-pentofuranosyl)adenine by liquid-chromatography

Liquid chromatography was used to follow the degradation of monoamino analogues of 2'- or 3'-deoxyadenosine and of 9-(2-deoxy-beta-D-threo-pentofuranosyl) adenine or 9-(3-deoxy-beta-D-threo-pentofuranosyl) adenine in buffers of different pH and constant ionic strength (mu). Comparison of stabilities of some of the compounds under study with those of corresponding hydroxyl analogues showed that at acid pH the aminated compounds are more stable than the corresponding hydroxyl compounds. The higher stability associated with the presence of an amino group in the sugar is explained in function of pK(a) values, which were determined by C-13 NMR.status: publishe

Evaluation of the kinetics of hydrolysis of diamino analogues of 2 '- or 3 '-deoxyadenosine and of 9-(2-deoxy-beta-D-threo-pentofuranosyl)adenine or 9-(3-deoxy-beta-D-threo-pentofuranosyl)adenine by liquid chromatography

The degradation bf diamino analogues of 2'- or :3'-deoxyadenosine and of 9-(2-deoxy-beta-D-threo-pentofuranosyl)adenine or 9-(3-deoxy-beta-D-threo-pentofuranosyl)adenine in buffers of acid, neutral and alkaline pH and constant ionic strength was followed by liquid chromatography. The rate of hydrolysis at acid pH was found to be related to the position and configuration of the amino group on the sugar moiety. The compounds tinder study were found to be more stable than corresponding monoaminated nucleosides, which have been reported to be more stable: than the hydroxyl nucleosides. Liquid chromatographic analyses indicate that acid hydrolysis involves cleavage of the N-glycosyl bond as the major degradative process, together with another minor process, pH-rate profiles, activation parameters and deuterium isotope solvent effects are discussed.status: publishe