Development of a Rapid Chemical Identification System (RCIS) for the Detection of Fraudulently Labelled 5-nitroimidazole Products

Os Awofisayo,Oa Awofisayo,Ns Eyen

doi:10.4314/tjpr.v9i2.53706

Abstract

Purpose: A simple, reliable and rapid chemical identification system (RCIS) consisting of three colour reactions based on the functional groups in the molecule and two TLC methods was developed for preliminary detection of the 5–nitroimidazole drugs. Methods: Three members of this group of drugs (tablet form) available in the Nigerian market and labelled MA and MB for metronidazole, T A and TB for tinidazole and S for secnidazole, were used. The extraction of the active ingredient from the solid dosage form was performed using acetone. The reaction of the extracted drug with zinc and 1M hydrochloric acid at 100 oC converted the nitroimidazole group to a characteristic primary aromatic amine. TLC methods A and B were carried out on GF254 plates (5cm x 10cm) to further identify the individual members of the group. TLC method A with mobile phase consisting of acetone, ethyl acetate and ammonia (100:5:1) and method B with mobile phase consisting of acetone, chloroform and ammonia (100:15:1) were developed for the identification. Results: The aromatic character of 5-nitroimidazole was highlighted in nitric acid when combined with sulphuric acid resulting in an orange colour. 40% sodium hydroxide gave the alkali-induced characteristic orange colour of aromatic amino compounds. All the samples of the various brands gave characteristic colours that distinguished the compounds of the 5-nitroimidazole group as primary or secondary nitroimidazole compounds. Conclusion: Using the developed method, fraudulently labelled product 5-nitroimidazole antiprotozoal and antibacterial agents can now be detected in approx. 40 min with limited reagents and a simple TLC technique. The method is rugged, simple, and should be particularly handy for use in detecting substandard products of the drug in the drug distribution chain where sophisticated equipment are often not available. Keywords: 5–nitroimidazole; Fraudulently labeled; Chemical identification system; Antiprotozoal; Antibacterial.

Highlights

The world is confronted by the reality of large-scale counterfeit production of almost every conceivable drug [1,2]
It is not surprising that drugs are produced in gross violation of good manufacturing practices (GMP) and in utter disregard of pharmacopoeia standards [2,3]
The dangers posed by counterfeit products to public health in Nigeria have resulted in control measures by the Agency for Food and Drug Administration and Control (NAFDAC) such as daily enlightenment campaigns in the media [6,7]

Summary

Introduction

The world is confronted by the reality of large-scale counterfeit production of almost every conceivable drug [1,2]. It is not surprising that drugs are produced in gross violation of good manufacturing practices (GMP) and in utter disregard of pharmacopoeia standards [2,3] It is, desirable that deliberate and fraudulent labeling of drugs with respect to identity should be detected along the distribution chain as part of normal quality assurance processes [4]. There is the need to make available useful methods for accurately validating the authenticity and identity of available medications This is in view of the fact that the greatest health risk faced by people of the world today is the lack of appropriate medicines for treating both common and life-threatening illnesses [4,5]. Equipment with multi-component profiling for the screening of chemicals have been documented in literature but their high cost often render unaffordable to several stakeholder along the distribution chain in several developing countries [11,12]. FCIS is usually targeted at the molecular structure and functional groups in the drug molecule [14,15,16]

Methods

Discussion

Conclusion