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Papers by Noble Kuntworbe

Journal of chemistry, May 16, 2024

Advances in pharmacological and pharmaceutical sciences, Feb 7, 2024

BioMed Research International, Dec 17, 2023

Journal of Tropical Medicine, Jun 4, 2021

As one of the killer diseases in the world, malaria contributes to child mortality and global dea... more As one of the killer diseases in the world, malaria contributes to child mortality and global death annually. As a result, many reactive mechanisms have evolved to control and repel mosquitoes. e use of synthetic mosquito repellents with N,N-Diethylmeta-toluamide (DEET) is one of the popular interventions despite its dermatological limitations such as skin irritations. Ethnobotanical reviews have identified that the adoption of natural repellents promises high repellence on mosquitoes with minimal side effects compared with synthetic ones. However, this has received little attention in modern pharmaceutical literature. is research is focused on the formulation of a natural mosquito repellent from the oil extracted from Azadirachta indica (A. Juss). e oil cream was formulated in concentrations of 10% v/w, 12.5% v/w, 15% v/w, 17.5% v/w, and 20% v/w using an in vitro evaluation approach. Pharmacopoeia characteristics of the cream such as pH, viscosity, spreadability, and organoleptic properties were carried out to verify acidity, permeation, and flow properties of the formulated cream. e spreadability rate was inversely proportional to the concentration of the cream in terms of oil content falling from 1.24 gm/s to 0.84 gm/s from concentrations 10% v/w to 20% v/w correspondingly. Skin irritation tests, however, indicated traces of irritation at 20% v/w. Repellency properties of the cream revealed a lasting effect on the mosquitoes, although this was dependent on concentration levels. Formulations of 17.5% v/w and 20% v/w neem seed oil cream had an equal repellency effect of 87.5%, whereas the synthetic repellent had a repellency of 75% within a justifiable time frame for all the formulations. is work shows that plant-based mosquito repellents promise a healthier approach in controlling mosquito bites, protecting the skin, and preventing malaria.

DOAJ (DOAJ: Directory of Open Access Journals), May 1, 2018

The Scientific World Journal, May 4, 2023

Te development of a raw material into an acceptable pharmaceutical excipient involves evaluation ... more Te development of a raw material into an acceptable pharmaceutical excipient involves evaluation of the physicochemical and formulation properties of the potential raw material. Results from these evaluations may serve as a guide to subsequent use of the substance. Te objective of the study was to evaluate the physicochemical and microbiological properties of the stem bark gum of Cordia millenii tree in conventional release paracetamol tablets. From the physicochemical evaluations, the gum was slightly acidic and soluble in all the aqueous-based solvents, except 0.1 N HCl in which it was sparingly soluble. All the absorptive properties of the gum indicated tablet disintegrating potential for tablet formulation. Te total ash of the gum was higher than that of the international standard gum arabic. Micromeritic properties of the gum indicated the need for a fow aid to improve its fowability. Tere were no harmful microorganisms detected in the gum. Aerobic organisms and moulds and yeast were detected within permissible limits. Tablets formulated using six diferent concentrations of gum dispersions as a binder were generally soft and failed the USP T 80 standard of dissolution, indicating poor binding and drug releasing properties. Quality control properties of three diferent batches of tablets containing varying concentrations of the dry gum as a disintegrating agent were comparable to tablets containing equal concentrations of corn starch. Te in vitro drug releases were similar at all-time points of drug evaluation. Te gum can therefore be considered as a good disintegrant in the formulation of conventional release tablets.

Scientific African, Sep 1, 2021

Journal of the University of Science and Technology, Jul 24, 2007

Chemistry Central Journal, 2014

Background Hylocereus polyrhizus and Hylocereus undatus are two varieties of the commonly called ... more Background Hylocereus polyrhizus and Hylocereus undatus are two varieties of the commonly called pitaya fruits, and pitaya fruits have gained popularity in many countries all over the world. However, studies on chemical composition and the nutritional quality of pitaya flesh peel are limited. Results Extracts of pitaya (H. polyrhizus and H. undatus) peel were extracted by supercritical carbon dioxide extraction, and analyzed by gas chromatography–mass spectrometry analysis. Their cytotoxic and antioxidant activities were investigated. The main components of H. polyrhizus extract were β-amyrin (15.87%), α-amyrin (13.90%), octacosane (12.2%), γ-sitosterol (9.35%), octadecane (6.27%), 1-tetracosanol (5.19%), stigmast-4-en-3-one (4.65%), and campesterol (4.16%), whereas H. undatus were β-amyrin (23.39%), γ-sitosterol (19.32%), and octadecane (9.25%), heptacosane (5.52%), campesterol (5.27%), nonacosane (5.02%), and trichloroacetic acid, hexadecyl ester (5.21%). Both of the two extracts ...

Journal of Chemistry, 2022

Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based... more Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based combination therapies (ACTs) in Ghana. Their use, however, is associated with adulteration and substandard quality challenges. An HPLC method targeting quinoline and indoloquinoline antimalarial alkaloids was developed, validated, and applied to evaluate herbal and pharmaceutical antimalarial formulations (HPAFs) and starting materials (APIs). The separation/quantitation of the alkaloids (including quinine, quinidine, cinchonine, cinchonidine, dihydroquinine, dihydroquinidine, and cryptolepine) was achieved on a Zorbax SB-CN column (250 mm × 4.6 mm, 5 μm), with an isocratic elution system of methanol: trifluoroacetic acid (0.1%, v/v) (15 : 85, v/v) at 1.5 mL/min and 223 nm. Method validation was according to ICH Q2(R1) guidelines. It was then used to assess the quality of APIs (n = 3) and HPAFs (n = 44) including quinine-based pharmaceutical antimalarial formulations (QBPAFs) (n = 23) a...

Journal of Chemistry, 2022

Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based... more Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based combination therapies (ACTs) in Ghana. Their use, however, is associated with adulteration and substandard quality challenges. An HPLC method targeting quinoline and indoloquinoline antimalarial alkaloids was developed, validated, and applied to evaluate herbal and pharmaceutical antimalarial formulations (HPAFs) and starting materials (APIs). The separation/quantitation of the alkaloids (including quinine, quinidine, cinchonine, cinchonidine, dihydroquinine, dihydroquinidine, and cryptolepine) was achieved on a Zorbax SB-CN column (250 mm × 4.6 mm, 5 μm), with an isocratic elution system of methanol: trifluoroacetic acid (0.1%, v/v) (15 : 85, v/v) at 1.5 mL/min and 223 nm. Method validation was according to ICH Q2(R1) guidelines. It was then used to assess the quality of APIs (n = 3) and HPAFs (n = 44) including quinine-based pharmaceutical antimalarial formulations (QBPAFs) (n = 23) a...

Journal of Pharmacy & Pharmacognosy Research, 2018

Context: The fight against malaria is limited by the development of resistance of Plasmodium to m... more Context: The fight against malaria is limited by the development of resistance of Plasmodium to medication. This has led to an urgent search for alternative medicinal agents. Aims: To determine the affinity of cryptolepine for the red blood cell. Methods: HPLC method for the identification and quantification of cryptolepine was developed. Lipid solubility for both quinine (control) and cryptolepine was determined. Partitioning and repartitioning of cryptolepine into RBCs were studied. Time, concentration, temperature and pH were varied to see their effect on the partitioning of cryptolepine. Plasma protein binding was determined by the red blood cell partitioning method. Results: An accurate, precise and robust HPLC method for cryptolepine hydrochloride was developed. Cryptolepine and quinine had lipophilicity of 0.91 ± 0.02 and 1.52 ± 0.27, respectively. The highest partitioning values of 2.02 ± 0.08 for cryptolepine and 0.93 ± 0.02 for quinine were obtained at 40 minutes. Concentr...

Fruit juice extracts of Citrus sinensis var. late Valencia at different stages of development (3,... more Fruit juice extracts of Citrus sinensis var. late Valencia at different stages of development (3, 6, 10 and 12 months and fallen senescent fruits) were investigated for antimicrobial and antioxidant activities. Antimicrobial activity was determined using a modified Kirby-Bauer agar diffusion method and minimum inhibitory concentrations (MIC) were determined by the micro broth dilution method against strains of Bacillus subtilis NCTC 10073, Candida albicans ATCC 10231, Escherichia coli ATCC 25922, Proteus vulgaris NCTC 4175, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923. Antioxidant activity was evaluated by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging method using N-propyl gallate as standard antioxidant. IC50 values were then determined. Results revealed that the fruit juice extracts demonstrated broad spectrum antibacterial as well as antifungal activity with MIC values ranging from 8.00 to 20.00%, 16.00 to 28.00% , 24.00 to 32.00%, 28...

Advances in Pharmacological and Pharmaceutical Sciences, 2021

Dispersed systems such as emulsions are easily destabilised during processing and storage since t... more Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evalu...

Advances in Pharmacological and Pharmaceutical Sciences, 2021

Dispersed systems such as emulsions are easily destabilised during processing and storage since t... more Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evalu...

Determination of pKa and forced degradation of the indoloquinoline antimalarial compound cryptole... more Determination of pKa and forced degradation of the indoloquinoline antimalarial compound cryptolepine hydrochloride

AAPS PharmSciTech, 2012

Cryptolepine hydrochloride-loaded gelatine nanoparticles were developed and characterised as a me... more Cryptolepine hydrochloride-loaded gelatine nanoparticles were developed and characterised as a means of exploring formulation techniques to improve the pharmaceutic profile of the compound. Cryptolepine hydrochloride-loaded gelatine-type (A) nanoparticles were developed base on the double desolvation approach. After optimisation of formulation parameters including temperature, stirring rate, incubation time polymer and cross-linker (glutaraldehyde) concentrations, the rest of the study was conducted at two different formulation pH values (2.5 and 11.0) and by two different approaches to drug loading. Three cryoprotectants-sucrose, glucose and mannitol-were investigated for possible use for the preparation of freeze-dried samples. Nanoparticles with desired size mostly less than 350 nm and zeta potential above ±20 were obtained when formulation pH was between 2.5 and 5 and above 9. Entrapment efficiency was higher at pH 11.0 than pH 2.5 and for products formulated when drug was loaded during the second desolvation stage compared to when drug was loaded onto pre-formed nanoparticles. Further investigation of pH effect showed a new isoelectric point of 6.23-6.27 at which the zeta potential of nanoparticles was zero. Sucrose and glucose were effective in low concentrations as cryoprotectants. The best formulation produced an EC 50 value of 227.4 μM as a haemolytic agent compared to 51.61 μM by the free compound which is an indication of reduction in haemolytic side effect. There was sustained released of the compound from all formulation types over a period of 192 h. Stability data indicated that the nanosuspension and freeze-dried samples were stable at 4 and 25°C, respectively, over a 52-week period, but the former was less stable at room temperature. In conclusion, cryptolepine hydrochloride-loaded gelatine nanoparticles exhibited reduced haemolytic effect compared to the pure compound and can be developed further for parenteral delivery.

Resumen Context: Malarial remains a leading course of death in developing countries. Current trea... more Resumen Context: Malarial remains a leading course of death in developing countries. Current treatment protocol involves the use of artemisininbased combination therapy. In endemic areas, cost of treatment is a concern hence generic prescription is on the high. It is therefore necessary to investigate how equivalent or otherwise the generics are to the innovator brand Coatem®. Aims: To compare the physicochemical properties and in vivo bioavailability of a locally manufactured generic artemether-lumefantrine tablet formulation and that of the innovator brand sold on the Kumasi market, Ghana. Methods: The most used locally manufactured generic and the innovator brands were sampled from retail pharmacies. The samples were confirmed by colorimetry. Pharmaceutical equivalence of the brands was determined using compendial tests. In vivo bioavailability study on the two brands was done using a two-period, single dose, cross-over design involving 20 healthy rabbits. Pharmacokinetic paramet...

Journal of chemistry, May 16, 2024

Advances in pharmacological and pharmaceutical sciences, Feb 7, 2024

BioMed Research International, Dec 17, 2023

Journal of Tropical Medicine, Jun 4, 2021

As one of the killer diseases in the world, malaria contributes to child mortality and global dea... more As one of the killer diseases in the world, malaria contributes to child mortality and global death annually. As a result, many reactive mechanisms have evolved to control and repel mosquitoes. e use of synthetic mosquito repellents with N,N-Diethylmeta-toluamide (DEET) is one of the popular interventions despite its dermatological limitations such as skin irritations. Ethnobotanical reviews have identified that the adoption of natural repellents promises high repellence on mosquitoes with minimal side effects compared with synthetic ones. However, this has received little attention in modern pharmaceutical literature. is research is focused on the formulation of a natural mosquito repellent from the oil extracted from Azadirachta indica (A. Juss). e oil cream was formulated in concentrations of 10% v/w, 12.5% v/w, 15% v/w, 17.5% v/w, and 20% v/w using an in vitro evaluation approach. Pharmacopoeia characteristics of the cream such as pH, viscosity, spreadability, and organoleptic properties were carried out to verify acidity, permeation, and flow properties of the formulated cream. e spreadability rate was inversely proportional to the concentration of the cream in terms of oil content falling from 1.24 gm/s to 0.84 gm/s from concentrations 10% v/w to 20% v/w correspondingly. Skin irritation tests, however, indicated traces of irritation at 20% v/w. Repellency properties of the cream revealed a lasting effect on the mosquitoes, although this was dependent on concentration levels. Formulations of 17.5% v/w and 20% v/w neem seed oil cream had an equal repellency effect of 87.5%, whereas the synthetic repellent had a repellency of 75% within a justifiable time frame for all the formulations. is work shows that plant-based mosquito repellents promise a healthier approach in controlling mosquito bites, protecting the skin, and preventing malaria.

DOAJ (DOAJ: Directory of Open Access Journals), May 1, 2018

The Scientific World Journal, May 4, 2023

Te development of a raw material into an acceptable pharmaceutical excipient involves evaluation ... more Te development of a raw material into an acceptable pharmaceutical excipient involves evaluation of the physicochemical and formulation properties of the potential raw material. Results from these evaluations may serve as a guide to subsequent use of the substance. Te objective of the study was to evaluate the physicochemical and microbiological properties of the stem bark gum of Cordia millenii tree in conventional release paracetamol tablets. From the physicochemical evaluations, the gum was slightly acidic and soluble in all the aqueous-based solvents, except 0.1 N HCl in which it was sparingly soluble. All the absorptive properties of the gum indicated tablet disintegrating potential for tablet formulation. Te total ash of the gum was higher than that of the international standard gum arabic. Micromeritic properties of the gum indicated the need for a fow aid to improve its fowability. Tere were no harmful microorganisms detected in the gum. Aerobic organisms and moulds and yeast were detected within permissible limits. Tablets formulated using six diferent concentrations of gum dispersions as a binder were generally soft and failed the USP T 80 standard of dissolution, indicating poor binding and drug releasing properties. Quality control properties of three diferent batches of tablets containing varying concentrations of the dry gum as a disintegrating agent were comparable to tablets containing equal concentrations of corn starch. Te in vitro drug releases were similar at all-time points of drug evaluation. Te gum can therefore be considered as a good disintegrant in the formulation of conventional release tablets.

Scientific African, Sep 1, 2021

Journal of the University of Science and Technology, Jul 24, 2007

Chemistry Central Journal, 2014

Background Hylocereus polyrhizus and Hylocereus undatus are two varieties of the commonly called ... more Background Hylocereus polyrhizus and Hylocereus undatus are two varieties of the commonly called pitaya fruits, and pitaya fruits have gained popularity in many countries all over the world. However, studies on chemical composition and the nutritional quality of pitaya flesh peel are limited. Results Extracts of pitaya (H. polyrhizus and H. undatus) peel were extracted by supercritical carbon dioxide extraction, and analyzed by gas chromatography–mass spectrometry analysis. Their cytotoxic and antioxidant activities were investigated. The main components of H. polyrhizus extract were β-amyrin (15.87%), α-amyrin (13.90%), octacosane (12.2%), γ-sitosterol (9.35%), octadecane (6.27%), 1-tetracosanol (5.19%), stigmast-4-en-3-one (4.65%), and campesterol (4.16%), whereas H. undatus were β-amyrin (23.39%), γ-sitosterol (19.32%), and octadecane (9.25%), heptacosane (5.52%), campesterol (5.27%), nonacosane (5.02%), and trichloroacetic acid, hexadecyl ester (5.21%). Both of the two extracts ...

Journal of Chemistry, 2022

Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based... more Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based combination therapies (ACTs) in Ghana. Their use, however, is associated with adulteration and substandard quality challenges. An HPLC method targeting quinoline and indoloquinoline antimalarial alkaloids was developed, validated, and applied to evaluate herbal and pharmaceutical antimalarial formulations (HPAFs) and starting materials (APIs). The separation/quantitation of the alkaloids (including quinine, quinidine, cinchonine, cinchonidine, dihydroquinine, dihydroquinidine, and cryptolepine) was achieved on a Zorbax SB-CN column (250 mm × 4.6 mm, 5 μm), with an isocratic elution system of methanol: trifluoroacetic acid (0.1%, v/v) (15 : 85, v/v) at 1.5 mL/min and 223 nm. Method validation was according to ICH Q2(R1) guidelines. It was then used to assess the quality of APIs (n = 3) and HPAFs (n = 44) including quinine-based pharmaceutical antimalarial formulations (QBPAFs) (n = 23) a...

Journal of Chemistry, 2022

Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based... more Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based combination therapies (ACTs) in Ghana. Their use, however, is associated with adulteration and substandard quality challenges. An HPLC method targeting quinoline and indoloquinoline antimalarial alkaloids was developed, validated, and applied to evaluate herbal and pharmaceutical antimalarial formulations (HPAFs) and starting materials (APIs). The separation/quantitation of the alkaloids (including quinine, quinidine, cinchonine, cinchonidine, dihydroquinine, dihydroquinidine, and cryptolepine) was achieved on a Zorbax SB-CN column (250 mm × 4.6 mm, 5 μm), with an isocratic elution system of methanol: trifluoroacetic acid (0.1%, v/v) (15 : 85, v/v) at 1.5 mL/min and 223 nm. Method validation was according to ICH Q2(R1) guidelines. It was then used to assess the quality of APIs (n = 3) and HPAFs (n = 44) including quinine-based pharmaceutical antimalarial formulations (QBPAFs) (n = 23) a...

Journal of Pharmacy & Pharmacognosy Research, 2018

Context: The fight against malaria is limited by the development of resistance of Plasmodium to m... more Context: The fight against malaria is limited by the development of resistance of Plasmodium to medication. This has led to an urgent search for alternative medicinal agents. Aims: To determine the affinity of cryptolepine for the red blood cell. Methods: HPLC method for the identification and quantification of cryptolepine was developed. Lipid solubility for both quinine (control) and cryptolepine was determined. Partitioning and repartitioning of cryptolepine into RBCs were studied. Time, concentration, temperature and pH were varied to see their effect on the partitioning of cryptolepine. Plasma protein binding was determined by the red blood cell partitioning method. Results: An accurate, precise and robust HPLC method for cryptolepine hydrochloride was developed. Cryptolepine and quinine had lipophilicity of 0.91 ± 0.02 and 1.52 ± 0.27, respectively. The highest partitioning values of 2.02 ± 0.08 for cryptolepine and 0.93 ± 0.02 for quinine were obtained at 40 minutes. Concentr...

Fruit juice extracts of Citrus sinensis var. late Valencia at different stages of development (3,... more Fruit juice extracts of Citrus sinensis var. late Valencia at different stages of development (3, 6, 10 and 12 months and fallen senescent fruits) were investigated for antimicrobial and antioxidant activities. Antimicrobial activity was determined using a modified Kirby-Bauer agar diffusion method and minimum inhibitory concentrations (MIC) were determined by the micro broth dilution method against strains of Bacillus subtilis NCTC 10073, Candida albicans ATCC 10231, Escherichia coli ATCC 25922, Proteus vulgaris NCTC 4175, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923. Antioxidant activity was evaluated by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging method using N-propyl gallate as standard antioxidant. IC50 values were then determined. Results revealed that the fruit juice extracts demonstrated broad spectrum antibacterial as well as antifungal activity with MIC values ranging from 8.00 to 20.00%, 16.00 to 28.00% , 24.00 to 32.00%, 28...

Advances in Pharmacological and Pharmaceutical Sciences, 2021

Dispersed systems such as emulsions are easily destabilised during processing and storage since t... more Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evalu...

Advances in Pharmacological and Pharmaceutical Sciences, 2021

Dispersed systems such as emulsions are easily destabilised during processing and storage since t... more Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evalu...

Determination of pKa and forced degradation of the indoloquinoline antimalarial compound cryptole... more Determination of pKa and forced degradation of the indoloquinoline antimalarial compound cryptolepine hydrochloride

AAPS PharmSciTech, 2012

Cryptolepine hydrochloride-loaded gelatine nanoparticles were developed and characterised as a me... more Cryptolepine hydrochloride-loaded gelatine nanoparticles were developed and characterised as a means of exploring formulation techniques to improve the pharmaceutic profile of the compound. Cryptolepine hydrochloride-loaded gelatine-type (A) nanoparticles were developed base on the double desolvation approach. After optimisation of formulation parameters including temperature, stirring rate, incubation time polymer and cross-linker (glutaraldehyde) concentrations, the rest of the study was conducted at two different formulation pH values (2.5 and 11.0) and by two different approaches to drug loading. Three cryoprotectants-sucrose, glucose and mannitol-were investigated for possible use for the preparation of freeze-dried samples. Nanoparticles with desired size mostly less than 350 nm and zeta potential above ±20 were obtained when formulation pH was between 2.5 and 5 and above 9. Entrapment efficiency was higher at pH 11.0 than pH 2.5 and for products formulated when drug was loaded during the second desolvation stage compared to when drug was loaded onto pre-formed nanoparticles. Further investigation of pH effect showed a new isoelectric point of 6.23-6.27 at which the zeta potential of nanoparticles was zero. Sucrose and glucose were effective in low concentrations as cryoprotectants. The best formulation produced an EC 50 value of 227.4 μM as a haemolytic agent compared to 51.61 μM by the free compound which is an indication of reduction in haemolytic side effect. There was sustained released of the compound from all formulation types over a period of 192 h. Stability data indicated that the nanosuspension and freeze-dried samples were stable at 4 and 25°C, respectively, over a 52-week period, but the former was less stable at room temperature. In conclusion, cryptolepine hydrochloride-loaded gelatine nanoparticles exhibited reduced haemolytic effect compared to the pure compound and can be developed further for parenteral delivery.

Resumen Context: Malarial remains a leading course of death in developing countries. Current trea... more Resumen Context: Malarial remains a leading course of death in developing countries. Current treatment protocol involves the use of artemisininbased combination therapy. In endemic areas, cost of treatment is a concern hence generic prescription is on the high. It is therefore necessary to investigate how equivalent or otherwise the generics are to the innovator brand Coatem®. Aims: To compare the physicochemical properties and in vivo bioavailability of a locally manufactured generic artemether-lumefantrine tablet formulation and that of the innovator brand sold on the Kumasi market, Ghana. Methods: The most used locally manufactured generic and the innovator brands were sampled from retail pharmacies. The samples were confirmed by colorimetry. Pharmaceutical equivalence of the brands was determined using compendial tests. In vivo bioavailability study on the two brands was done using a two-period, single dose, cross-over design involving 20 healthy rabbits. Pharmacokinetic paramet...