Drug Stability

Traditional Chinese Herbal Medicine (TCHM) contain multiple botanicals, each of which contains many compounds that may be relevant to the medicine's putative activity. Therefore, analytical techniques that look at a suite of compounds, including their respective ratios, provide a more rational approach to the authentication and quality assessment of TCHM.

OBJECTIVES: To investigate transdermal absorption enhancement of gel containing elastic niosomes loaded with gallic acid in the semipurified fraction isolated from Terminalia chebula Retz. (Combretaceae) galls. MATERIALS AND METHODS: Nonelastic and elastic niosomes loaded with gallic acid in pure form or in the semipurified fraction were developed. Rat skin permeation by vertical Franz diffusion cells of gallic acid from various gel formulations containing elastic niosomes loaded with gallic acid or the semipurified fraction was performed.

CONTEXT: The galls of Terminalia chebula Retz. (Combretaceae) frequently appear in many Thai Lanna medicinal plant recipes for promotion of longevity. OBJECTIVE: The objective of this study was to evaluate the skin anti-aging of gel containing niosomes loaded with a semi-purified fraction containing gallic acid from T. chebula galls. METHOD: The semi-purified fraction containing phenolic compounds including gallic acid isolated from T.

An efflux pump inhibitor, SK-20 (5-(3,4-methylenedioxyphenyle)-4 ethyl-2E,4E-pentadienoic acid piperidide), was assessed for its toxicity at three different pharmacological profiles: acute, sub-acute and general pharmacology with pharmacokinetics. In acute study, the SK-20 was found safe up to a dose of 2000 mg/kg (b.wt.); and at sub-acute, dosages of 50 and 100 mg/kg (b.wt.) were found to be safe.

Two recently reported hit compounds, COR627 and COR628, underpinned the development of a series of 2-(acylamino)thiophene derivatives. Some of these compounds displayed significant activity in vitro as positive allosteric modulators of the GABAB receptor by potentiating GTP?S stimulation induced by GABA at 2.5 and 25 ?M while failing to exhibit intrinsic agonist activity. Compounds were also found to be effective in vivo, potentiating baclofen-induced sedation/hypnosis in DBA mice when administered either intraperitoneally or intragastrically.

Neurotransmitters and their metabolites in central nervous system were known to play a significant role in sedation and hypnosis. A rapid and sensitive UFLC-MS/MS method for simultaneous determination of serotonin, 5-hydroxyindole acetic acid (5-HIAA), tryptophan (Try), dopamine (DA), norepinephrine (NE), ?-aminobutyric acid (GABA), glutamic acid (Glu) and acetylcholine (Ach) in rat brain without derivatization, ion-pairing reagent or pre-concentration was developed.

AIMS: To determine the pharmacokinetics of artemether (ARM) and its principal active metabolite, dihydroartemisinin (DHA) in healthy volunteers. METHODS: Six healthy male Malaysian subjects were given a single oral dose of 200 mg artemether. Blood samples were collected to 72 h. Plasma concentrations of the two compounds were measured simultaneously by reversed-phase h.p.l.c. with electro-chemical detection in the reductive mode. RESULTS: Mean (+/- s.d.) maximum concentrations of ARM, 310 +/- 153 micrograms l-1, were reached 1.88 +/- 0.21 h after drug intake.

The shelf lives of preserved antimalarial agent-predosed plates according to the type of wrapping and the temperature of storage were studied by measuring the 50% inhibitory concentrations of drug for Plasmodium falciparum 3D7. The shelf life of mefloquine was 8 weeks at 25 degrees C; and those of artesunate, artemisinin, and dihydroartemisinin were a minimum of 24, 12, and 8 weeks, respectively, at 4 degrees C.

BACKGROUND AND OBJECTIVE: There are several reports of sub-standard and counterfeit antimalarial drugs circulating in the markets of developing countries; we aimed to review the literature for the African continent. METHODS: A search was conducted in PubMed in English using the medical subject headings (MeSH) terms: 'Antimalarials/analysis'[MeSH] OR 'Antimalarials/standards'[MeSH] AND 'Africa'[MeSH]' to include articles published up to and including 26 February 2007.

A new series of 6 dimeric trioxane sulfones has been prepared from the natural trioxane artemisinin in five or six chemical steps. One of these thermally and hydrolytically stable new chemical entities (4c) completely cured malaria-infected mice via a single oral dose of 144 mg/kg. At a much lower single oral dose of only 54 mg/kg combined with 13 mg/kg of mefloquine hydrochloride, this trioxane dimer 4c as well as its parent trioxane dimer 4b also completely cured malaria-infected mice. Both dimers 4c and 4b were potently and selectively cytotoxic toward five cancer cell lines.