Joko Sulistiyo Journal of Drug Delivery & Therapeutics. 2023; 13(6):141-144 ISSN: 2250-1177 [141] CODEN (USA): JDDTAO Available online on 15.06.2023 at http://jddtonline.info Journal of Drug Delivery and Therapeutics Open Access to Pharmaceutical and Medical Research Copyright © 2023 The Author(s): This is an open-access article distributed under the terms of the CC BY-NC 4.0 which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited Open Access Full Text Article Research Article Assay of Diphenhydramine HCl in Syrup by High Performance Liquid Chromatography Joko Sulistiyo Health Polytechnic of Jakarta II, Jakarta, Indonesia Article Info: _____________________________________________ Article History: Received 23 April 2023 Reviewed 14 May 2023 Accepted 27 May 2023 Published 15 June 2023 _____________________________________________ Cite this article as: Sulistiyo J, Assay of Diphenhydramine HCl in Syrup by High Performance Liquid Chromatography, Journal of Drug Delivery and Therapeutics. 2023; 13(6):141-144 DOI: http://dx.doi.org/10.22270/jddt.v13i6.5885 _____________________________________________ *Address for Correspondence: Joko Sulistiyo, Health Polytechnic of Jakarta II, Jakarta, Indonesia Abstract _____________________________________________________________________________________________________________________ Cough is a natural response from the respiratory tract by increasing the clearance of secretions and particles from mucus, irritants, foreign particles, and microbes, so that it can act as a body defense. One way that can be done to relieve cough symptoms is to use symptomatic drugs. Diphenhydramine HCl is an antihistamine that belongs to the first generation H1 receptor antagonist (H1 blocker) group which has sedative and anti-allergic properties. Diphenhydramine HCl is used to treat sneeze, runny nose, watery eyes, itches, skin rashes, and other cold symptoms or other allergies. Diphenhydramine HCl is also used to treat motion sickness and to induce sleep. The purpose of this study was to determine the contents of diphenhydramine HCl syrup sold in the market. This test uses the High Performance Liquid Chromatography (HPLC) method with acetonitrile as a mobile phase; water; triethylamine (50;50;0.5). The results obtained the average content of Diphenhydramine HCl 102.5%. So it can be concluded that the cough medicine sample meets the requirements because the contents are not less than 90% and not more than 110% based on the Indonesian Pharmacopoeia Edition VI 2020. Keywords: Cough, Diphenhydramine HCl, High Performance Liquid Chromatography (HPLC) INTRODUCTION Coughing is a natural response from the respiratory tract by increasing the cleaning of secretions and particles from mucus, irritants, foreign particles, and microbes, so that they can act as the body's defense. There are two types of cough, namely productive cough (phlegm) and non-productive cough (dry). A productive cough is a cough that produces phlegm or mucus (sputum) so it is known as a cough with phlegm. Non- productive cough is a cough without phlegm, this cough is often triggered by food particles, irritants, cigarette smoke, and changes in temperature. 1–4 One way that can be done to relieve cough symptoms is to use symptomatic drugs. There are many types of drugs used in cough management, depending on the type of cough that has the most effect on cough symptoms. Based on their mechanism of action, cough medicines can be grouped into 3 major groups, namely: expectorants, which have two mechanisms of action. First, it reacts directly by stimulating mucus secretion so that mucus is thinner and easier to remove. Second, by reacting indirectly by irritating the gastrointestinal tract which affects the respiratory system thereby increasing mucus secretion; mucolytic, as the name implies, mucolytic is a cough medicine with phlegm that works by destroying phlegm formations so that the phlegm becomes watery; and antitussive, are drugs that work to reduce the sensitivity of the cough center in the brain to incoming stimuli. 5–7 Diphenhydramine HCl is an antihistamine which belongs to the first generation of H1 receptor antagonists (H1 blockers) which has sedative and antiallergic properties. Diphenhydramine HCl is used to treat sneezing, runny nose, watery eyes, itching, skin rashes, and other cold or allergy symptoms. Diphenhydramine HCl is also used to treat motion sickness and to induce sleep. Diphenhydramine HCl has physical properties in the form of a white crystalline powder, odorless and has a bitter taste. Diphenhydramine HCl is easily soluble in water, in ethanol, and in chloroform; slightly soluble in acetone; very difficult to dissolve in benzene and in ether. 8,9 Because there are already many companies that produce the drug Diphenhydramine HCl, it is necessary to test the drug preparation with several existing parameters and according to the requirements. A quality drug is a drug that is guaranteed that the drug has the potential or power to be used for its purpose, meets purity requirements, has clear and correct identity and labeling, is packaged in appropriate packaging and is protected from damage and contamination, looks good, and is free from contamination. from defects or damage. 10 Drugs that are marketed in dosage form in the form of syrup must go through several testing processes. One of them is the determination of the levels of active substance preparations. The author wants to know whether the drug Diphenhydramine HCl in the form of syrup that is circulating in the market is of good quality to be marketed to the public or not. 11,12