George Owusu-Dapaah - Academia.edu (original) (raw)

Uploads

Papers by George Owusu-Dapaah

Journal of Pharmaceutical Research International

Background: Labelling plays an important role in informing healthcare providers and patients on a... more Background: Labelling plays an important role in informing healthcare providers and patients on appropriate information on drugs and how to optimize their therapeutic effects whilst minimizing potential side-effects. For these reasons, drug regulatory bodies have specifications which drug manufacturers are required to conform to in the labelling of their products. Aim: The purpose of the study was to find out whether locally manufactured medicines on the Ghanaian market meet the specifications set out by the Ghana Standards Authority. Place and Duration of Study: The study was carried out in Kumasi, Ghana, between April 2018 and September 2018. Methodology: The labels of one hundred locally produced drugs were assessed based on the general labelling rules for drugs outlined in the Legislative Instrument, L.I. 1541. Some parameters used for the assessment were dates of manufacture and expiry, batch number, indications, active ingredients, handling precautions, etc. Results: Results o...

Journal of Pharmacognosy and Phytochemistry, 2020

In traditional medicinal systems, different parts of the same plant may show therapeutic activiti... more In traditional medicinal systems, different parts of the same plant may show therapeutic activities against a specific condition, but with different potencies. It is against this background that the current study seeks to compare the antimicrobial activities of different morphological parts of mango plant. Using the agar-well diffusion, and the broth dilution methods the antimicrobial activities of ethanolic extracts of the stem bark, leaf and seed of mango were investigated against some microbes. From the study, the seed extract exhibited the greatest antimicrobial activity of average diameters of zones of inhibition in the range of 14–19 mm for a 10mg/ml concentration, and 12–16 mm for a 5mg/ml. The bark and leaf extracts gave a range of 8–12 mm at the stated concentrations. The best minimum inhibitory concentration was against S. aureus and it was of 125µg/ml of the seed extract. The study has shown that the bark, leaf and seed extracts each of mango has antimicrobial activity, a...

Journal of Pharmacognosy and Phytochemistry, 2016

Herbal preparations are formulated into various dosage forms that are used in treatment of diseas... more Herbal preparations are formulated into various dosage forms that are used in treatment of diseases including infections. In Ghana, many herbal mixtures are advertised and sold for treatment of microbial infections. The current study sought to investigate the purported antimicrobial activities of four herbal mixtures in the Ghanaian market, using the Agar Diffusion method. The samples investigated did not exhibit any antimicrobial activity against both Gram-positive and Gram-negative bacteria, and Candida albicans used in the study. Most of the plants constituting the components of the herbal mixtures assessed, however, have been documented to have antimicrobial activities against the microbes used in the study. The inability of the samples to show antimicrobial activity may be attributed to low concentrations of the active compounds in the mixture. Water is the vehicle mostly used for extraction in such mixtures, and it is possible that larger volumes of the vehicle vis-à-vis the p...

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A thesis submitted to the College of Health Sciences in partial fulfillment of the requirement fo... more A thesis submitted to the College of Health Sciences in partial fulfillment of the requirement for the Degree of Master of Pharmacy, 1993

Bioorganic & Medicinal Chemistry Letters, 2007

The continual increase in drug resistance; the lack of new chemotherapeutic agents; the toxicity ... more The continual increase in drug resistance; the lack of new chemotherapeutic agents; the toxicity of existing agents and the increasing morbidity with HIV co-infection mean the search for new antileishmanial agents has never been more urgent. We have identified the benzodiazepines as a structural class for antileishmanial hit optimisation, and demonstrated that their in vitro activity is comparable with the clinically used drug, sodium stibogluconate, and that the compounds are not toxic to macrophages.

Bioorganic & Medicinal Chemistry, 2012

A library of 1,4-benzodiazepines has been synthesised and evaluated for activity against Trypanos... more A library of 1,4-benzodiazepines has been synthesised and evaluated for activity against Trypanosoma brucei, a causative parasite of Human African Trypanosomiasis (HAT). The most potent of these derivatives has an MIC value of 0.97 lM. Herein we report the design, synthesis and biological evaluation of the abovementioned compounds.

International Journal of Technology and Management Research, 2020

This study demonstrates the importance of the Brine Shrimp Bioassay in drug discovery. It uses tw... more This study demonstrates the importance of the Brine Shrimp Bioassay in drug discovery. It uses two medicinal plants, Zanthoxylum xanthoxyloides and Tiliacora funifera. Extracts of Zanthoxylum xanthoxyloides were prepared using water, ethanol, chloroform and diethylether, and each subjected to Brine Shrimp Bioassay. The bioactivities of the extracts were found to be in the order diethylether (LD50=0.958 mg/ml), followed by ethanol (LD50=1.874 mg/ml), water(LD50=2.322 mg/ml), and chloroform (3.518 mg/ml). From Tiliacora funifera is isolated the compound funiferine, which is derivatized to obtain o-methylfuniferine and o-isopropylfuniferine. These were subjected to the brine shrimp bioassay, and the structure –activity relationship (SAR) was determined. The results showed that o-isopropylfuniferine is the most bioactive (LD50 = 9.07 mg/ml), followed by o-methylfuniferine (LD50 =38 mg/ml) with funiferine showing the least activity (LD50 =50.25 mg/ml). The SAR of the compounds indicates ...

British Journal of Pharmaceutical Research, 2015

Aims: Malaria is hyper-endemic in many parts of Ghana, and a greater percentage of the population... more Aims: Malaria is hyper-endemic in many parts of Ghana, and a greater percentage of the population use herbal preparations to treat the disease. This study was conducted to find out the medicinal plants that constitute the components of antimalarial herbal mixtures sold in Ghana. Place and Duration of Study: The study was conducted in Accra (the capital city of Ghana) and Kumasi (the second largest city in the country) by researchers from the Department of Pharmaceutical Sciences at Kumasi Polytechnic. It was carried out between May and July, 2012. Methodology: The study was based on direct observation and recording of information on available antimalarial herbal products in some Pharmacies and Herbal Medicine Shops in the two cities. Results: The study identified forty one different herbal mixtures used as antimalarials. Fifty seven plants belonging to 28 plant families, and one animal product (honey), were found to be the components of the herbal mixtures. Cryptolepis sanguinolenta and Azadirachta indica, respectively