ABSTRACT
Introduction: An “aroma-active compound” (AAC) has a “flavor”- ie: a “distinct taste and odor”. An example is menthol. All aromatic plants (APs), including some medicinal plants, such as Mentha×piperita (Family Lamiaceae), produce a group of fat-soluble secondary metabolites called “essential oils” (EOs) for various ecophysiological reasons. An EO has a “flavor” because it contains one or more AACs. A typical EO is a complex mixture of several AACs, with wide ranging, dose-dependent pharmacological/ toxic effects. Owing to their complexity and variability, many EOs need to be standardized to ISO’s criteria. Professional use of EOs/ AAPs in food and drugs is controlled by good manufacturing practice (GMP). Aim: Given the immense diversities in sources, chemical structures, and bioactivities of EOs/ AACs, which are greatly patronized in foods and drugs, this review focused on their: i) sources in plants, beneficial attributes and liabilities; and ii) chemistry and analytical methods, in order to gain a better insight into their regulation in foods and drugs. Methodology: Using the 2009 Angiosperm Phylogenic Grouping (APG) of plants as a guide, pertinent literature was perused to ascertain: i) the taxa of APs; ii) their EOs/ AAPs; and iii) the methods for analyzing EOs/ AACs in raw materials (RMs) and finished products (FPs). Results: The literature revealed scores of AACs with varying health implications. But their levels in samples are usually unknown, or extremely hard to ascertain, owing to costs and complexities of the methods used. Conclusions: Given the wide ranging effects of EOs/ AAPs vis-à-vis the dearth of data on their levels in samples, it is recommended that their regulation in FPs should focus on: i) controlling the wholesomeness of RMs; and ii) on enforcing strict GMP in using such RMs. Meanwhile relevant agencies should sponsor research into more cost-effective methods.
ABSTRACT
Background: The World Health Organization (WHO) recommended that the toxicity data of a traditional medicine (TM) product that has been in use for 20 years or more without untoward effects should be determined, as the first step in its research and development (R&D). Such data in conjunction with efficacy data would be used to develop an appropriate dosage form of the product. A key objective in researching such a product is to validate the basis of the therapy, including the formula. Such validation, and any attempt to modernize the product, should be guided by an understanding of the traditional know-how. The Nigerian National Institute for Pharmaceutical Research and Development (NIPRD) utilized this approach in developing Niprisan, an antisickling drug, based on a TM product used since antiquity in Yoruba Medicine. Aim: This article aimed to advocate the continuance and improvement of the WHO model of herbal drug research and regulation (HDRR) as the most logical approach for adoption by researchers and regulators. Methodology: NIPRD’s adoption of the WHO model since 1989 was reviewed in parallel with trends in herbal drug research worldwide; and within the contexts of regulatory practices by Nigeria’s National Agency for Food and Drug Administration and Control (NAFDAC) and the European Medicines Evaluation Agency (EMEA), with a view to identifying more effective strategies within the WHO paradigm for HDRR. Conclusion: Drug regulatory agencies (DRAs) like NAFDAC require effective laws, policies and quality management systems (QMS) to execute their mandates effectively. On the other hand, NIPRD’s output depends upon proper actions by a seasoned and responsive DRA. Therefore, noting that NIPRD and NAFDAC were both created by military decrees in 1989 and 1992 respectively, rather than by parliament acts, it is recommended that in addition to instituting more effective laws and policies to regulate NAFDAC, both NIPRD and NAFDAC need to adopt and implement suitable QMS for self-regulation, eg: ISO 9001 for whole organizations; and ISO/IEC 17250 for the laboratories.
ABSTRACT
Aims: Sequel to the resurgence of TB co-infection in HIV/AIDS patients in sub-Saharan Africa, efavirenz has become an important component of the highly active antiretroviral treatment (HAART). The objective of this study therefore is to provide a simple reversedphase high performance liquid chromatographic (HPLC) method for the determination of efavirenz in human plasma. Study Design: Method development and experimental study. Place and Duration of Study: School of Pharmacy, University of Nairobi, Nairobi, Kenya, between October 2009 and September 2010. Methodology: A 500μl drug-free plasma sample was each placed in six different centrifuge tubes (2ml) and varying aliquots of the stock solution (100μg/ml) of efavirenz were spiked and vortexed for 60sec to give concentrations of 0.5, 1.0, 2.0, 4.0, 8.0 and 16μg/ml for calibration standards and 2.0, 4.0, 8.0 and 16.0μg/ml for quality control samples. The off-column sample pretreatment was carried out by protein precipitation using ice-cold acetonitrile. The samples were chromatographed in a phenomenex (C18) 5μm particle size column with 250x4.6mm I.D and UV detection at 254nm using a mobile phase, which was made up of a mixture of solutions A and B. Both consisted of acetonitrile, 25mM ammonium acetate buffer and glacial acetic acid in proportions of 90:10:0.1 and 10:90:0.1(v/v), respectively. The analytical technique was validated for precision, accuracy and analyte recovery. Results: The calibration plot for efavirenz was found to be linear over the concentration range of 0.5 to 16.0μg/ml with the regression line equation obtained as y=26842x–409.4 and the regression coefficient (R2=0.999), which allows for accurate reading of the concentrations of the test samples. The RSD (%) in intraday and interday assays ranged from 0.44 to 0.78%. Accuracy ranged from 92 to 110% and the recovery was >97%. Conclusion: This new HPLC method is simple, reproducible and cost-effective and can be used for therapeutic drug monitoring of efavirenz in HIV/AIDS patients on HAART as demonstrated in this study.