Towards the development of analytical monograph specifications for the quality assessment of the medicinal plant Phyllanthus urinaria.

Many people in developing countries rely on herbal remedies for their primary healthcare needs. The challenge however is that several of these products lack proper documentation of quality and safety. To ensure consistent quality, validated methods are needed to establish and control quality attributes associated with identity, purity, and levels of bioactive constituents of the respective herbal materials. The present study focused on Phyllanthus urinaria (PU), a widely used medicinal plant in Ghana and West Africa that lacks the necessary quality control standards. The study aimed to develop an HPTLC identification method, which together with UPLC-ESI-Q-TOF-MS/MS analysis established the identity of PU samples and differentiated PU from other closely related Phyllanthus species. Quantitative UPLC and HPTLC methods were developed to assess the contents of selected active markers in the PU samples, which invariably led to the proposal of acceptance criteria for the active markers. Prior to the content analyses, the sample extraction procedure was optimized through the use of Design of Experiment method. The effects of harvest time and geographic origin on the content of active compounds were demonstrated in the investigations. PU samples were also found to be contaminated with higher levels of pesticides like chlorpyrifos and folpet. Essentially, this study provides analytical protocols, insights into the quality status of PU samples in Ghana, and analytical specifications contained in a drafted monograph for future consideration in regional and subregional African pharmacopoeias.

Bioequivalence studies of cetirizine tablets using the urine excretion data of healthy Ghanaian male volunteers.

Background: In the wake of economic challenges, the role of generic medicines has become crucial in meeting the healthcare needs of people. Their use, however, can only be guaranteed if established to be bioequivalent to their corresponding innovator products. Aim: In this study, we assess the suitability of a generic brand of cetirizine hydrochloride tablet to be used in place of the innovator brand on the Ghanaian market through bioequivalence assessment. Method: An HPLC bioanalytical method was developed and validated for the detection and quantitation of cetirizine in a urine matrix. This was then used to quantify the amount of cetirizine excreted unchanged in urine samples of 12 healthy male volunteers collected over a 24-h period using a two-way crossover design approach. Results: Chromatographic separation was successfully achieved with an isocratic elution on a reverse-phase column. The mean retention time for cetirizine was 2.890 ± 0.243 min. The mean cumulative amounts of cetirizine in the reference and test drugs excreted were 5.69 ± 0.98 mg and 5.82 ± 1.96 mg respectively. Other pharmacokinetic parameters including mean relative Areas Under Curve (AUC0-24) of 13.32 and 13.05 µg/mL, and peak Concentration (Cmax) of 3.378 and 3.043 µg/mL at the times at which Cmax was observed (Tmax) being 7.25 and 7.42 min were established respectively for the reference and test drugs. The relative bioavailability was determined to be 102.28, making the locally manufactured brand bioequivalent to the innovator brand. Conclusion: The locally manufactured test Cetirizine drug was found to be bioequivalent with the innovator brand and could serve as a suitable alternative to the latter. Additionally, relevant pharmacokinetic parameters for cetirizine has been established using urinary excretion data.

Development of an Analytical Workflow to Support the Establishment of Monographs in African Pharmacopoeias - Combretum mucronatum Leaves as Example.

Herbal medicines are invaluable in African medicine, but quality and safety are not documented in many cases. Besides controlled farming, validated quality control methods are needed to ensure identity, purity, and content. Analytical specifications within modern monographs are needed for consistent batch quality. Combretum mucronatum leaves are widely used in West Africa, but state-of-the-art quality control methods and specifications are non-existent. The aim of the following study was the development of ICH-validated chromatographic protocols for identity, purity, content assay, and analytical specifications for consideration into pharmacopoeial monographs. UPLC-ESI-Q-TOF-MS/MS was used for untargeted phytochemical information on composition. Optimisation of extraction was based on phytochemical profiling. HPTLC was used for differentiation of C. mucronatum from other Combretum species and UPLC for simultaneous determination of 7 marker compounds. C. mucronatum batch analyses (n = 49) investigated the influence of harvest time and geographical origin. Pesticides screening from a 349-compound panel were carried out. 30 compounds, identified by LC-MS, were used for characterization of the plant material. Orietin, isoorientin, vitexin and isovitexin were used as specific marker compounds for qualitative and quantitative HPTLC purposes, while UPLC quantified additionally epicatechin, procyanidins B2 and C1. Influence of harvest time and geographic origin on the content of marker compounds was observed. Differences in the metabolite profiles of C. mucronatum compared to related Combretum species were established for quality control purposes. Contamination with high amoounts of chlorpyrifos, and folpet (sum of folpet and phtalimide, expressed as folpet) were also observed.The study provides analytical protocols, analytical specifications and a drafted monograph for consideration for African pharmacopoeias, and reveals potential challenges in the quality of C. mucronatum.

Quality assessment of African herbal medicine: A systematic review and the way forward.

BACKGROUND: In Africa, herbalism supplements allopathic medicine's efforts to ensure Universal Health Coverage attainment. This review was conducted to identify and to summarise current literature on methodological approaches used for quality control of herbal medicines in Africa, to evaluate the gaps associated with existing strategies within context of best practices, and make recommendations for future improvements. METHODS: A systematic search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were screened and assessed for eligibility. RESULTS: 118 articles were included into the study. There was a high preference for impurity profiling tests (77%) indicating the prioritization for tests that guarantee safety despite the limited analytical resources available. Other classes of tests reported included identification tests (29%), physicochemical tests (18%), and content assays (12%). Although standard methods exist in preparing samples for impurity tests, different techniques were observed in different studies, and this could lead to differences in analytical outcomes. Content assays focused on single marker assessments, which may be inadequate to comprehensively assess the quality of products. CONCLUSION: This review provides knowledge of existing strengths and challenges for herbal medicine quality assessments in Africa. For future it is recommended to implement more studies on contaminants (e.g. mycotoxins) and pharmaceutical adulterants. The use of chemometrics to develop analytical methods should be promoted. Also, stakeholders in the medicine quality industry in Africa need to effectively collaborate to establish a well co-ordinated and harmonized system to provide a sustainable framework for the GACP and GMP guided production and quality assurance of herbal medicines.

Doctoral Graduate Programs in the Pharmaceutical Sciences: An International Survey.

This publication represents the first to report global information on characteristics and requirements of doctoral programs in the pharmaceutical sciences in schools/colleges of Pharmacy. Survey responses (140 responses) were received from doctoral programs in 23 countries, with the greatest number of responses obtained from Japan, followed by India and the United States. Program characteristics and requirements, and student and faculty information, including graduate placement, in programs in Asia, North America, Europe, Africa and Australia were compared. Survey responses indicated differences in entrance requirements for doctoral programs with minimum requirements being a bachelor's degree, pharmacy degree or master's degree, including a M.Phil. degree. Programs differed widely in size in all geographical areas, but there was a similar emphasis on core educational learning outcomes (core competencies) and Ph.D. graduation requirements including qualifying examinations, thesis defense with internal and external reviewers and requirements for peer-reviewed publications. Additionally, three-quarters of programs indicated that there was external review of their programs every 2-4 or 5-7 years. Female students and female faculty mentors represented about 50% of students/faculty in programs in most geographical areas. Placement of students after graduation indicated that the highest percentage went into the pharmaceutical industry in Asia (predominantly India) and North America, with a lower percentage in Europe, Africa and Australia.

Master's Graduate Programs in the Pharmaceutical Sciences: An International Survey.

Information on master's programs in the pharmaceutical sciences is lacking; this manuscript addresses this gap in the literature, by reporting on the results of an international survey performed in 2021 of master's programs in the pharmaceutical sciences offered at Schools/Colleges of Pharmacy. Ninety-six responses were received from universities from 23 countries, with the greatest number of responses obtained from India, followed by the United States and Japan. Master's programs in the pharmaceutical sciences are generally full time and 2 years in duration. Only 3% of programs were reported to be examination-based, while the remaining 97% had a research component with 70% of programs having a thesis defense with external and/or internal examiners. Master's programs tended to be larger in Asia and Europe than in North America; as well, programs in North America tended to have more international students. Didactic coursework was included in 96% of master's programs in North America, but only in 38% of Asian and 58% of European programs. The predominant placement of graduates from master's programs in Asia was in the pharmaceutical industry (70%); this contrasted with programs in Europe, Africa and North America where 28-36% enter careers in the pharmaceutical industry and higher percentages enter Ph.D. programs. The major challenge identified by programs was funding of faculty and of graduate students, although decreasing career opportunities was identified as a challenge in Asia and Africa.

Anthelmintic Agents from African Medicinal Plants: Review and Prospects.

Soil-transmitted helminthiasis affects more than 1.5 billion people globally and largely remains a sanitary problem in Africa. These infections place a huge economic burden on poor countries and affect livestock production, causing substantial economic losses and poor animal health. The emergence of anthelmintic resistance, especially in livestock, and the potential for its widespread in humans create a need for the development of alternative therapies. Medicinal plants play a significant role in the management of parasitic diseases in humans and livestock, especially in Africa. This report reviews anthelmintic studies that have been conducted on medicinal plants growing in Africa and published within the past two decades. A search was made in various electronic databases, and only full articles in English were included in the review. Reports show that aqueous and hydroalcoholic extracts and polar fractions obtained from these crude extracts form the predominant (80%) form of the extracts studied. Medicinal plants, extracts, and compounds with different chemical groups have been studied for their anthelmintic potential. Polyphenols and terpenoids are the most reported groups. More than 64% of the studies employed in vitro assays against parasitic and nonparasitic nematode models. Egg hatch inhibition, larval migration inhibition, and paralysis are the common parameters assessed in vitro. About 72% of in vivo models involved small ruminants, 15% rodents, and 5% chicken. Egg and worm burden are the main factors assessed in vivo. There were no reports on interventions in humans cited within the period under consideration. Also, few reports have investigated the potential of combining plant extracts with common anthelmintic drugs. This review reveals the huge potential of African medicinal plants as sources of anthelmintic agents and the dire need for in-depth clinical studies of extracts, fractions, and compounds from African plants as anthelmintic agents in livestock, companion animals, and humans.

Monitoring and risk assessment of pesticide residues in selected herbal medicinal products in Ghana.

The high patronage of herbal medicinal products in Ghana for the treatment of diverse disease conditions raises concerns about patient safety, given that much of the raw materials for production are obtained from the wild or farmlands potentially exposed to varied agrochemical residues. Therefore, the work sought to investigate the contamination of herbal medicinal products with pesticide residues and assess the potential risk posed to patients. As a result, validated gas chromatography with mass spectrometry as a detector was used to determine forty-two pesticides in thirty herbal medicinal products. The performance parameters of the method such as linearity, accuracy, and precision were found as acceptable. Pesticide residues such as chlorpyrifos and/or bifenthrin were found in 4/30 herbal medicinal products. Specifically, 3/30 herbal medicinal products contained only one pesticide, while 1/30 was contaminated with both pesticide residues. The levels of pesticide residue contamination ranged between 2.5 and 5.0 µg/kg. The acute hazard quotient and chronic hazard quotient for the two pesticide residues were evaluated and ranged between 0.21 and 0.92% and between 8.21 × 10-4 and 5.88 × 10-3%. The detected pesticide residue levels are below the maximum residue limit values, which may not cause acute and chronic health risks due to intake of the selected herbal medicinal product. Nevertheless, patient safety and potential public health risk can be reduced by regular monitoring, and regulation of pesticide residue levels in herbal medicinal products.

Ultraviolet-Visible Spectroscopy and Chemometric Strategy Enable the Classification and Detection of Expired Antimalarial Herbal Medicinal Product in Ghana.

To meet the growing demand for complementary and alternative treatment for malaria, manufacturers produce several antimalarial herbal medicinal products. Herbal medicinal products regulation is difficult due to their complex chemical nature, requiring cumbersome, expensive, and time-consuming methods of analysis. The aim of this study was to develop a simple spectroscopic method together with a chemometric model for the classification and the identification of expired liquid antimalarial herbal medicinal products. Principal component analysis model was successfully used to distinguish between different herbal medicinal products and identify expired products. Principal component analysis showed a clear class separation between all five herbal medicinal products (HMP) studied, with explained variance for first and second principal components as 37.51% and 26.38%, respectively, while the third principal component had 18.74%. Support vector machine classification gave specificity and accuracy of 1.00 (100%) for training set data for all the products. The validation set HMP1, HMP2, and HMP3 had sensitivity, specificity, and accuracy of 1.00. HMP4 and HMP5 had sensitivity and specificity of 0.90 and 1.00, respectively, and an accuracy of 0.98. The support vector machine classification and principal component analysis models were successfully used to identify expired herbal medicinal products. This strategy can be used for rapid field detection of expired liquid antimalarial herbal medicinal products.

MALDI-HRMS imaging and HPLC-HRESI-MSn characterisation of kaurane diterpenes in the fruits of Xylopia aethiopica (Dunal) A. Rich (Annonaceae).

INTRODUCTION: Kaurane diterpenes, notably xylopic acid, have demonstrated important biological activities including analgesia, anti-oxidant, antimicrobial and cytotoxicity. The fruits of Xylopia aethiopica have been reported to be a rich source of kaurane diterpenes. OBJECTIVE: An analytical approach for detailed imaging and characterisation of selected kaurane diterpenes was developed using matrix-assisted laser desorption/ionisation high-resolution mass spectrometry (MALDI-HRMS) imaging techniques and high-performance liquid chromatography-high resolution electrospray ionisation-tandem mass spectrometry (HPLC-HRESI-MSn ) studies, respectively. METHODS: The images of the compounds were constructed based on selected ions from their HRESI-MS spectra. The matrix employed comprised a solution of α-cyano-4-hydroxycinnamic acid (HCCA) in acetonitrile-water with trifluoroacetic acid (TFA). HPLC-HRESI-MSn measurements were conducted on an LTQ-Orbitrap spectrometer equipped with a heated electrospray ionisation (HESI)-II source. RESULTS: The analytical strategy adopted showed the spatial distribution of the compounds in the fruits of X. aethiopica based on the dominant ions at m/z 301.2163 [M + H - HOCOCH3 ]+ and m/z 399.1932 [M + K]+ for xylopic acid, m/z 317.2111 [M + H]+ and m/z 355.1670 [M + K]+ for 15-oxo-ent-kaur-16-en-19-oic acid and m/z 303.2319 [M + H]+ for ent-kaur-16-en-19-oic acid. The fragmentation patterns of the compounds were proposed based on the HRESI-MSn measurements. CONCLUSIONS: The study revealed the spatial variability, differential behaviours and specificity of the selected kaurane diterpenes in the fruit, seed and pericarp. The compounds under study were predominantly restricted to the pericarp of the fruit with trace amounts in the seed.

Synthesis of conformationally restricted 1,3-dioxanes to analyze the bioactive conformation of 1,3-dioxane-based σ1 and PCP receptor antagonists.

The receptor binding profile of 2-phenyl-4-(aminoethyl)-1,3-dioxanes is dependent on the additional substituent in 2-position, the substituents at the amino moiety and the stereochemistry. Herein, conformationally restricted 1,3-dioxanes bearing an axially oriented phenyl moiety in 2-position were prepared and pharmacologically evaluated. Two subsequent intramolecular transacetalization reactions represent the key steps in the synthesis of the tricyclic system. The resulting alcohol 17 was transformed into amines 20-23 with axially (a-series) or equatorially oriented aminoethyl moiety (b-series). The primary amines 20a and 20b did not interact with the PCP binding site of the NMDA receptor, which is explained by the additional methylene moiety between the acetalic center and the phenyl moiety, the missing substituent at the acetalic position and/or a non-optimal three-dimensional arrangement of the pharmacophoric elements. The benzylamine 21b with an equatorially oriented aminoethyl moiety shows high σ1 affinity (Ki=5.9nM). Compared with the conformationally flexible 1,3-dioxane 5, the σ1 affinity of 21b is 3-fold and the σ1/σ2 selectivity is 5-fold increased.

Double Intramolecular Transacetalization of Polyhydroxy Acetals: Synthesis of Conformationally-Restricted 1,3-Dioxanes with Axially-Oriented Phenyl Moiety.

The synthesis of conformationally-restricted 1,3-dioxanes with a phenyl moiety fixed in an axial orientation at the acetalic center is described. Starting with diethyl 3-hydroxyglutarate (15), benzaldehyde acetal 12a and acetophenone ketal 12b bearing a protected 1,3,5-trihydroxypentyl side chain in the o-position were prepared. The first acid-catalyzed intramolecular transacetalization gave a mixture of diastereomeric 2-benzofurans 18 (ratio of diastereomers 2:2:1:1). After OH group deprotection, the second intramolecular transacetalization afforded tricyclic alcohol 14a (2-(1,5-epoxy-1,3,4,5-tetrahydro-2-benzoxepin-3-yl]ethan-1-ol). Analogous cyclizations led to the corresponding silyl ether 22a (19%) and azide 23a (13%). Whereas tricyclic alcohol 14a was obtained as a 1:1 mixture of diastereomers, the silyl ether 22a and the azide 23a afforded only one diastereomer. This observation indicates a faster cyclization of the minor diastereomers providing the thermodynamically-favored compounds with equatorially-oriented substituents in the 3-position of the tricyclic 1,5-epoxy-2-benzoxepine system. In general, acetophenone-derived ketalic compounds (b-series) required very mild reaction conditions and gave lower yields than the corresponding acetalic compounds (a-series).