Pharmaceutical Compounding and Dispensing Pharmaceutical Compounding and Dispensing SECOND EDITION John F Marriott BSc, PhD, MRPharmS, FHEA Professor of Clinical Pharmacy Aston University School of Pharmacy, UK Keith A Wilson BSc, PhD, FRPharmS Head of School Aston University School of Pharmacy, UK Christopher A Langley BSc, PhD, MRPharmS, MRSC, FHEA Senior Lecturer in Pharmacy Practice Aston University School of Pharmacy, UK Dawn Belcher BPharm, MRPharmS, FHEA Teaching Fellow, Pharmacy Practice Aston University School of Pharmacy, UK Published by the Pharmaceutical Press 1 Lambeth High Street, London SE1 7JN, UK 1559 St Paul Avenue, Gurnee, IL 60031, USA Ó Pharmaceutical Press 2010 is a trade mark of Pharmaceutical Press Pharmaceutical Press is the publishing division of the Royal Pharmaceutical Society of Great Britain First edition published 2006 Second edition published 2010 Typeset by Thomson Digital, Noida, India Printed in Great Britain by TJ International, Padstow, Cornwall ISBN 978 0 85369 912 5 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the copyright holder. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. The right of John F Marriott, Keith A Wilson, Christopher A Langley and Dawn Belcher to be identified as the author of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act, 1988. A catalogue record for this book is available from the British Library. Contents Preface ix About the authors x Acknowledgements xi Museum of the Royal Pharmaceutical Society xii British Society for the History of Pharmacy xiv Online material xv Part 1 History of compounding 1 1 Historical perspective 3 The origins of the pharmacy profession 3 Foundation of the Royal Pharmaceutical Society of Great Britain 5 Pharmacy legislation 6 Development of the pharmacopoeias 8 2 Obsolete dosage forms, equipment and methods of preparation 17 Obsolete pharmaceutical preparations and preparative methods 18 Old pharmaceutical equipment 34 Old pharmaceutical containers 38 3 Historical weights and measures 41 Metrication 41 Part 2 Pharmaceutical forms and their preparation 47 4 Key formulation skills 49 Weights and measures 49 Medication strength 59 5 Extemporaneous dispensing 65 Guide to general good practice requirements 65 Suitable record keeping 67 Equipment 67 Product formulae 74 Ingredients 75 Storage and labelling requirements 91 Pharmaceutical packaging 96 vi | Contents 6 Solutions 101 Introduction and overview 101 General principles of solution preparation 103 Oral solutions 104 Gargles and mouthwashes 105 Enemas and douches 105 External solutions 105 Worked examples 106 Summary of essential principles relating to solutions 112 7 Suspensions 115 Introduction and overview 115 General principles of suspension preparation 116 Oral diffusible suspensions 117 Oral indiffusible suspensions 119 Suspensions for external use 119 Worked examples 120 Summary of essential principles relating to suspensions 127 8 Emulsions 131 Introduction and overview 131 Formulation of emulsions 133 General method of preparation of an emulsion using the dry gum method 135 Stability of emulsions 136 Emulsions for external use 137 Worked examples 138 Summary of essential principles relating to emulsions 151 9 Creams 153 Introduction and overview 153 Terminology used in the preparation of creams, ointments, pastes and gels 153 General principles of cream preparation 154 Worked examples 156 Summary of essential principles relating to creams 160 10 Ointments, pastes and gels 163 Introduction and overview 163 Ointments 163 Pastes 165 Gels 167 Worked examples 170 Summary of essential principles relating to ointments, pastes and gels 181 11 Suppositories and pessaries 183 Introduction and overview 183 General principles of suppository and pessary preparation 184 General method for suppository preparation 186 Worked examples 187 Summary of essential principles relating to suppositories and pessaries 192 Contents | vii 12 Powders and capsules 195 Introduction and overview 195 Bulk powders for external use 195 Bulk oral powders 196 Individual unit dose powders 197 Unit dose capsules 199 Worked examples 202 Summary of essential principles relating to powders and capsules 205 13 Specialised formulation issues 207 Introduction and overview 207 Posology 207 Dermatological extemporaneous formulation 213 Further reading 215 Part 3 Product formulae 217 Preface 219 14 Creams 225 15 Dusting powders 229 16 Internal mixtures 231 17 Liniments, lotions and applications 249 18 Ointments and pastes 253 19 Powders 257 20 Miscellaneous formulae 259 Appendix 1 Glossary of terms used in formulations 261 Appendix 2 Abbreviations commonly used in pharmacy 263 Appendix 3 Changing substance names from British Approved Names to recommended International Non-Proprietary Names 265 Bibliography 271 Index 273 Preface Pharmacists or their pharmaceutical equivalents have as a reference-based tutorial to the methods employed been responsible for compounding medicines for cen- in medicines’ compounding. The text has been designed turies. Recently this role has been challenged in the to allow students and practitioners to be able to exam- pharmaceutical literature with suggestions and recom- ine either all or part of the subsequent chapters in order mendations that it is inappropriate for the pharmaceu- to familiarise themselves with the compounding tech- tical practitioner to compound medicines in a local niques necessary to produce products of appropriate pharmacy environment. Notwithstanding this valid quality and efficacy. In addition, the text is supported debate, it is clear that a vast array of skills and knowl- by moving images in order to augment the necessary edge with regard to medicines’ compounding has been techniques and expertise. accrued and refined, certainly over the last two centu- The text also has a role when considering the ries. In the present environment it is possible that this design and implementation of standard operating pro- knowledge and skill base might be dispersed and ulti- cedures (SOPs) pertinent to certain sectors of profes- mately lost. However, it is not beyond the bounds of sional practice today. Although we do not expect all imagination to conceive that there will be times, albeit practitioners of pharmacy to be compounding medi- possibly in the face of some form of environmental, cines on a daily basis, we hope that should the need cultural or local emergency, when pharmacists might arise this text will effectively support any work of this be called upon to extemporaneously compound med- nature that might be encountered. icines when conventional supply chains are either This second edition has updated the first edition unavailable or have broken down. and, to assist the student compounder, the text now This text has been designed with a number of func- includes examples of the pharmaceutical label for each tions in mind. First, it is important to be aware of some worked example. of the historical pathways that have led to the present technological position of pharmacists. In addition, John F Marriott unless many of the antiquated measuring systems, Keith A Wilson methodologies and formulations are preserved in Christopher A Langley some reference work, they might be lost forever, or Dawn Belcher at least be totally unavailable except to the dogged Birmingham, United Kingdom historian. Primarily, however, this work is intended January 2010 About the authors John F Marriott Chertsey. Upon registration, he returned to Aston John Marriott is a pharmacist, registered in the UK for University to undertake a PhD within the Medicinal the last 25 years. He practised in both community and Chemistry Research Group before moving over full hospital sectors, holding a variety of positions, latterly time to pharmacy practice. He is currently employed as Chief Pharmacist at the Royal Wolverhampton as a Senior Lecturer in Pharmacy Practice, specialising Hospitals NHS Trust, before joining the academic in teaching the professional and legal aspects of the pharmacy department at Aston University, where he degree programme. took over as the Head of the Pharmacy School in 2005. His research interests predominantly surround He has a proactive role in teaching in the depart- pharmacy education but he is also involved in research ment and is working on the development of electronic examining the role of the pharmacist in both primary methodologies to support pharmacy learning and and secondary care. This includes examining the teaching. In addition he has wide, active research pharmacist’s role in public health and the reasons interests, principally in the areas of clinical pharmacy/ behind and possible solutions to the generation of pharmacology and medicines management. Current waste medication. project themes revolve around the PK/PD of paediatric drug use and formulation, control of antibiotic pre- Dawn Belcher scribing and medicines wastage. Dawn Belcher is a qualified pharmacist who graduated from the Welsh School of Pharmacy in 1977 and then Keith A Wilson undertook her pre-registration training with Boots the Keith A Wilson graduated in pharmacy from Aston Chemist at their Wolverhampton store. After regis- University in 1971. He