Comparative in vitro and in vivo study of a sugar-coated chloroquine preparation marketed in Tanzania versus an ordinary brand

Antimalarials for children with Plasmodium vivax infection: Current status, challenges, and research priorities

The aim of this narrative review is to summarise efficacy and pharmacokinetic data for Plasmodium vivax in children. The burden of P. vivax malaria in children continues to remain a significant public health issue, and the need for improved treatment regimens for this vulnerable population is critical. Relapse after re-activation of dormant liver-stage hypnozoites poses additional challenges for treatment, elimination, and control strategies for P. vivax. Whilst it is recognised that paediatric pharmacology may be significantly influenced by anatomical and physiological changes of childhood, dosing regimens often continue to be extrapolated from adult data, highlighting the need for antimalarial dosing in children to be evaluated in early phase clinical trials. This will ensure that globally recommended treatment regimens do not result in suboptimal dosing in children. Furthermore, the development of affordable paediatric formulations to enhance treatment acceptability and widespread G6PD testing to facilitate use of anti-hypnozoite treatment such as primaquine and tafenoquine, should be further prioritised. As the world prepares for malaria elimination, a renewed focus on P. vivax malaria provides an ideal opportunity to harness momentum and ensure that all populations, including children have access to safe, efficacious, and correctly dosed antimalarial therapies.

Review of the quality of pediatric medications in developing countries

The quality of essential medicines for pediatric populations in developing countries is largely unknown. This review examines quality studies (2000-2011) of medicines on the WHO Essential Medicine List for Children, the quality of a subset of pediatric formulations, and the association of these poor quality medicines with adverse clinical outcomes. We searched Embase, Medline, BIOSIS, and IPA using MeSH subject terms for quality measures, medicine formulations, and substandard medicines and combined these with 267 medicines, and 91 low-income and lower-middle-income countries. Seventy articles met our inclusion criteria examining the quality of 75 medicines from 28 countries. Content and dissolution tests were utilized most often. Results indicate that antibacterials, antifungals, and antiretrovirals were consistently of good quality. Quality tests on pediatric formulations were performed on 55 of 75 of the medicines studied and followed the general trend of quality results. Three studies were included that examined clinical consequences of substandard medicines-two cases of diethylene glycol poisoning and one case of substandard malaria drugs. We conclude that there is a need for more quality studies of pediatric formulations of essential medicines in developing countries and their clinical consequences.

Antimalarial drug quality in Africa

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. Data were augmented with reports on the quality of antimalarial drugs in Africa obtained from colleagues in the World Health Organization. We summarized the data under the following themes: content and dissolution; relative bioavailability of antimalarial products; antimalarial stability and shelf life; general tests on pharmaceutical dosage forms; and the presence of degradation or unidentifiable impurities in formulations.

RESULTS AND DISCUSSION

The search yielded 21 relevant peer-reviewed articles and three reports on the quality of antimalarial drugs in Africa. The literature was varied in the quality and breadth of data presented, with most bioavailability studies poorly designed and executed. The review highlights the common finding in drug quality studies that (i) most antimalarial products pass the basic tests for pharmaceutical dosage forms, such as the uniformity of weight for tablets, (ii) most antimalarial drugs pass the content test and (iii) in vitro product dissolution is the main problem area where most drugs fail to meet required pharmacopoeial specifications, especially with regard to sulfadoxine-pyrimethamine products. In addition, there are worryingly high quality failure rates for artemisinin monotherapies such as dihydroartemisinin (DHA); for instance all five DHA sampled products in one study in Nairobi, Kenya, were reported to have failed the requisite tests.

CONCLUSIONS

There is an urgent need to strengthen pharmaceutical management systems such as post-marketing surveillance and the broader health systems in Africa to ensure populations in the continent have access to antimalarial drugs that are safe, of the highest quality standards and that retain their integrity throughout the distribution chain through adequate enforcement of existing legislation and enactment of new ones if necessary, and provision of the necessary resources for drug quality assurance.