WHO, essential drugs list

The main use of TLC in analysis of amoxicillin and its formulated products is as an identity test. A major study [105] using silica gel and silanised silica gel plates with thirty five different mobile phases and iodine vapour detection produced a system, on silanised plates with ammonium acetate/acetone mobile phase, in which amoxicillin was separated from all the other penicillins studied. A slightly modified version of this system was subsequently introduced into the European and British Pharmacopoeia monographs for amoxicillin trihydrate and sodium salt [2]. The British [57,58] and US [9] Pharmacopoeias specify other TLC systems for identification of amoxicillin in formulated products. Simple TLC methods have been developed for identification of several compounds on the WHO essential drugs list, to help combat counterfeiting [106]. For amoxicillin, systems using ethyl acetate/acetic acid/water or acetone/toluene/acetic acid/water with silica gel plates were recommended. 

This entry describes the three most important drugscreening methods in use at this time, for TB, macrolide antibiotics, and drugs from the World Health Organization (WHO) Essential Drug List. All of these are based on thin-layer chromatography (TLC). 

Lindenberg M, Dressman J, Kopp S. Classification of orally administered drugs on the WHO Essential Medicines list according to the BCS. Eur J Pharm Biopharm 2004 58 265-278. 

Laing, R. 2003. Personal Reflections on 25 Years of the WHO Model List for Essential Medicines. WHO Essential Drugs Monitor, No. 32 16. 

The Williams list of compounds [33] could also be scrutinized in the same manner as the WHO essential medicines list. It is however, an extensive set of substances and represents a wide range of therapeutic classes. Once again better and more recent sets could be devised for this study and the Williams set was selected as a useful representative set and for the large number of compounds it contained. As mentioned above this aspect of the study is being addressed in future work in these laboratories using the compounds listed in the AHFS Drug Handbook [51]. 

Zimbabwe also made a pragmatic and early shift to cheaper generic prescription policies to reduce cost of medicines in 1981, the Ministry of Health produced an essential drugs list (EDLIZ) (WHO, 1995), and this formed the basis for local medicines production strategies. Zimbabwean entrepreneurs established Varichem Pharmaceuticals (Pvt) Ltd in 1985 to serve this expanding market (UNIDO, 2007). 

The Use of Essential Drugs (Tenth Model List of Essential Drugs), WHO Technical reports Series No. 882, Eighth Report of the WHO Expert Committee, WHO, Geneva, 1998. 

AFRO Essential Drugs Price Indicator. Nearly 300 essential medicines and dosage forms are listed. Details are provided by Member States and low cost essential drugs suppliers. Published by the Regional Office for Africa and the WHO Collaborating Centre for the Quality Assurance of Medicines, University Potchefstroom, South Africa. 

The WHO list of Essential Drugs published at regular intervals is a model list which could be used at the national, regional, hospital and primary health centre levels (given in appendix III). 

Crucial, then, to the provision of essential medicines to the developing world (where government regulation and industry in many countries are disrupted by armed conflict), is the WHO EML. Originally produced in 1977, the WHO EML now contains over 300 products. By 1998, 140 countries had developed their own national lists of essential drugs. 

Appendix I WHO list of essential drugs Appendix 2 The prescription... 

If doctors were to limit their prescribing to the model list of Essential Drugs (WHO) (p. 28) and were to prescribe four drugs for any patient at any... 

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