World Health Organization - The fourth edition of The International Pharmacopoeia is now in preparation. The main purpose of this new edition is to consolidate the five separate volumes of the current third edition and to include those new monographs for antiretrovirals that were adopted by the Expert Committee on Specifications for Pharmaceutical Preparations in October 2004. In preparing this consolidated edition, an opportunity has been taken to review the General notices of the International Pharmacopoeia. Certain additions and amendments have also been made to the notices in order to clarify interpretation and facilitate application of the requirements by the user. Certain aspects of the layout and format of the publication will be improved. In the fourth edition, all the monograph texts will be brought together in one section and the method texts in another. Each of these major sections will be divided into appropriate sub-sections and the method texts will be numbered for ease of cross-reference.

Oral rehydration salts

The current monograph for oral rehydration salts has been revised to conform to the modified formula published in the 13th Model List of Essential Medicines (WHO Technical Report Series, No. 920, 2003) and in the Model Formulary 2004. The revised formula has a reduced sodium chloride and glucose content providing a solution with a reduced osmolarity of 245 mOsm/l. Due to the improved effectiveness of the reduced osmolarity ORS solution, especially for children with acute, non-cholera diarrhoea, WHO and UNICEF now recommend that countries use and manufacture this formulation in place of the previously recommended ORS, i.e. the one published in the third edition of The International Pharmacopoeia, which has a total osmolarity of 311 mOsm/l.

Method texts that have been updated include, for example, the text on high performance liquid chromatography (HPLC). This has been revised to clarify certain technical terms and to add advice on adjustment of chromatographic conditions as recommended by the WHO Expert Committee on Specifications for Pharmaceutical Preparations in October 2004.

New monographs

Monographs for the following antiretrovirals will be published in the fourth edition of The International Pharmacopoeia: didanosine, indinavir sulfate, nelfinavir mesilate, nevirapine, ritonavir, saquinavir, saquinavir mesilate. The adopted texts for these monographs were published in Drug Information, Volume 19 Number 1 (http://www.who.int/druginformation/vol19num1 2005/19-1table of contents.shtml) and are also available on the WHO website at (http://www.who.int/medicines/organization/qsm/activities/qualityassurance/pharmacopoeia/intpharm arvs.shtml). Meanwhile, work is continuing on the preparation of monographs for the associated dosage forms, for other antiretroviral substances and dosage forms and for fixed-dose combination products for the treatment of tuberculosis.