Ikechukwu Onyishi | University of Nigeria, Nsukka (original) (raw)
Papers by Ikechukwu Onyishi
Journal of Developing Drugs, May 11, 2016
African Journal of Biotechnology, Dec 31, 2013
Solidified reverse micellar solutions (SRMS) are reverse micelles containing lecithin and a trigl... more Solidified reverse micellar solutions (SRMS) are reverse micelles containing lecithin and a triglyceride, for example, SOFTISAN ® 142, which is hydrogenated coco glyceride. SRMS transform into a lamellar mesophase after melting on contact with water; this transformation enables controlled release of solubilized drugs. They offer potentials for sustained drug delivery of both hydrophilic and lipophilic drugs. SRMS have the advantage of providing more flexibility in controlling the drug release and protecting the encapsulated ingredients from chemical degradation. SRMS based systems influence the absorption of active ingredients through different mechanisms to modify the release of active ingredients, and improve drugs bioavailability. The types of SRMS-based drug delivery systems include solid lipid nanoparticles (SLN), solid lipid microparticles (SLM), tablets and suppositories amongst others. The work exhaustively reviews the advances in SRMS based carriers. Its formulation methods, characterisation and delivery systems were discussed in details.
African Journal of Pharmacy and Pharmacology, Dec 29, 2013
Recently, advances in pharmaceutical research is focused on new delivery systems utilizing new de... more Recently, advances in pharmaceutical research is focused on new delivery systems utilizing new devices to achieve modification of delivery time, targeting, as well as improve the in vivo solubility and hence bioavailability of poorly soluble drugs. Lipid based drug delivery systems (LDDS) consists of diverse group of formulations, each consisting of varying functional and structural properties that are amenable to modifications achieved by varying the composition of lipid excipients and other additives. LDDS has evolved, overtime, from micro-to nano-scale enhancing the efficacy and therapeutic application of these systems. LDDS are accepted, proven, commercially viable strategies for formulating challenging pharmaceutical molecules and can be tailored to meet a wide range of product requirements. Generally, most lipid drug delivery systems used as drug carriers have high stability, high carrier capacity, feasibility of incorporating both hydrophilic and hydrophobic substances and feasibility of variable routes of administration, including oral, topical, parenteral and pulmonary routes. LDDS can also be designed to allow modified drug release from matrices. LDDS could be broadly grouped into four: solid lipid particulate dosage forms, emulsion based systems, solid lipid tablets, and vesicular systems. Modifications from these four types include: lipospheres, solid lipid nanoparticles (SLNs), nano structured lipid carriers (NLC), lipid drug conjugate nanoparticles (LDC), self emulsifying formulations (SEFs), pickering emulsions, dry emulsions, micro and nano-emulsions, solidified reverse micellar solution (SRMS) based tablets, liposomes, herbosomes, cryptosomes and transferosomes amongst others. This work exhaustively reviewed the advances in LDDS and also drew comparison between the different types based on history, methods of manufacture, applications, advantages and disadvantages.
Bio Research Journal, Oct 16, 2022
The mouth is a vital route of drug administration with over 84 % of all medicines reportedly admi... more The mouth is a vital route of drug administration with over 84 % of all medicines reportedly administered through it. The gastrointestinal system is equally imbued with a lot of adaptive features that make the oral route even more conducive f or systemic drug delivery. The usef ulness of the oral route is, however challenged by the existence of numerous absorption barriers which limit the ef f ective absorption and delivery of drugs to their target sites in the body systems. Understanding these adaptive attributes , systemic barriers, and available strategies f or overcoming such barriers will not only be helpf ul in drug development and design but also usef ul to the f ormulation scientists desirous of optimizing drug delivery. The objective of this work was to review the gastrointestinal route of drug administration with respect to some biochemical and physio-anatomic f eatures that impede or enhance drug absorption and to highlight current strategies that have been deployed to achieve optimum per oral drug delivery. The current review reveals the emerging roles of nanocarriers in oral drug delivery. Polymeric nanocarriers enhance the solubility, targeting and saf ety prof iles of many important pharmacological agents. Novel systems that of f er protection against gastro enzymes and as such, promote oral ad ministration of biologicals are being widely investigated. Mechanical, magnetic, and acoustic energyinduced membrane perturbation are other delivery options receiving research attentions. It may be concluded that, with the avalanche of research ef f orts in the area, the oral route will maintain its prominence among other routes of drug administration.
African Journal of Pharmacy and Pharmacology, Jun 29, 2013
The purpose of this study was to evaluate the antioxidant properties of Vitis vinifera juice extr... more The purpose of this study was to evaluate the antioxidant properties of Vitis vinifera juice extract (grape) in rifampicin suspensions and to compare with that of ascorbic acid. Grape juice was extracted and used as antioxidant in both pure sample and commercial reconstituted samples of rifampicin. The rate of drug degradation was determined by spectroscopic method in a time dependent manner. Also, the antioxidant property of grape juice was compared with that of ascorbic acid. Phytochemical screening of the constituents in grape juice extract was carried out according to standard methods. The results revealed that rifampicin dispersions containing ascorbic acid (batches A1 to A5) showed significantly higher stability and had higher amount of drug remaining over time than the control (batch A6) containing no antioxidant (p < 0.05). However, the results revealed that grape fruit juice extract had higher antioxidant properties than the ascorbic acid (p < 0.05) in rifampicin dispersions. The results also indicated that increase in amount of both antioxidants significantly reduced the rate of drug degradation through oxidation, thereby causing a corresponding increase in the amount of rifampicin remaining over time. Grape juice extract contain alkaloids, carbohydrates, saponins, reducing sugars, steroids, tannins, proteins, flavonoids, resins, oils, terpenoids and acid compounds. Glycosides were however not found in the juice extract. Therefore, grape fruit juice extract could be used as a natural antioxidant in rifampicin suspensions.
Journal of Drug Delivery Science and Technology, 2014
The aims of the study were to investigate the excipient potentials of two natural lipids from Irv... more The aims of the study were to investigate the excipient potentials of two natural lipids from Irvingia wombolu and Moringa oleifera in rifampicin-loaded lipospheres. Lipospheres were formulated using different ratios of structured lipid matrices comprising of Phospholipon 90H (P90H) and Irvingia wombolu fats (IWF), and Phospholipon 90G (P90G) and Moringa oil (MO), respectively. Different in vitro test were studied including the particle size, encapsulation efficiency (EE), stability of formulations in simulated gastric fluid (SGF, pH 1.2), in vitro drug release, minimum inhibitory concentrations (MIC) and in vivo release. Results showed spherical particles within the size limit for lipospheres. Highest EE of 91.6 % was obtained. The lipospheres protected rifampicin against acidic degradation in the stomach (p < 0.05) and exhibited in vitro release of about 71.9 % at 12 h. In vivo release showed that the formulations had significantly higher in vivo absorption than the pure rifampicin sample (p < 0.05) and also showed higher antibacterial properties against Bacillus subtilis and Escherichia coli (p < 0.05). Rifampicin-loaded lipospheres had sustained release properties and could be used for once daily administration.
African Journal of Pharmacy and Pharmacology, Nov 22, 2013
The aim of the present study was to evaluate in vivo the anti-inflammatory, antinociceptive and u... more The aim of the present study was to evaluate in vivo the anti-inflammatory, antinociceptive and ulcerogenic properties of indomethacin tablets based on solidified reverse micellar solution (SRMS). SRMS consisting of mixtures of phospholipid (Phospholipon ® 90H) and triglyceride (Softisan ® 154) were prepared in the ratios of 1:1, 2:1 and 1:2, respectively. SRMS based tablets containing 75 mg of indomethacin each were prepared using validated plastic mould. The physicochemical properties of the tablet formulations were studied using both official and unofficial tests. Anti-inflammatory, analgesic/antinociceptive and ulcerogenic properties of indomethacin tablets based on SRMS were studied. The results showed that the physicochemical properties of the tablet formulations were significantly affected by the composition/ratio of the lipid matrix used. The softening time in SIF ranged from 53.7 ± 0.5 to 102.6 ± 0.5 min. Results of analgesic/antinociceptive properties showed that indomethacin tablets formulated with the SRMS 1:1 had an increase in pain reaction time at 7 h significantly (p < 0.05) different from the results exhibited by tablets formulated with the lipid matrices, SRMS 1:2 and 2:1 and the reference, which showed a decrease in pain reaction time at 7 h. Indomethacin tablets based on SRMS had good anti-inflammatory properties and also inhibited the ulcerogenicity of indomethacin by 70 to 80%. Therefore, indomethacin tablets based on SRMS could be used for improved oral bioavailability of indomethacin and to enhance patient's compliance due to inhibition of gastric irritation effect of this drug.
African Journal of Pharmacy and Pharmacology, Apr 22, 2013
The objectives of the present study were to formulate sustained release pyridoxine hydrochloride ... more The objectives of the present study were to formulate sustained release pyridoxine hydrochloride capsules and to study the effect of propylene glycol co-solvents on the in vitro properties of the capsules. All batches of formulations were made with fixed concentrations of binder-disintegrants, diluents and equal load of active pharmaceutical ingredient. The granules were prepared by wet granulation using propylene glycol water co-solvent as the wetting agent, sodium carboxymethylcellulose (SCMC) and maize starch were used as binder-disintegrant and kaolin was used as the diluents. The micromeritic properties of the granules were analysed by direct and indirect methods. The granules were encapsulated in hard gelatin capsule No. 1. The capsule weight uniformity, disintegration time and drug content were determined. In vitro dissolution test was performed in 0.1 N HCl, simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.2). The results showed that the particles size of granules ranged from 245 to 259 µm and had good flowability. The capsules complied with British Pharmacopoeia (BP) requirement for capsule weight uniformity. The drug content was within 90 to 110% of the average values. The results of in vitro drug release in SGF (pH, 1.2) showed that the release of pyridoxine hydrochloride was very slow and was significantly (P < 0.05) lower than the release in 0.1 N HCl and in SIF (pH, 7.2), respectively. Therefore, pyridoxine hydrochloride sustained release capsules could be formulated with kaolin as the diluent and propylene glycol co-solvent as the moistening agent in order to reduce the frequency of administration of this drug and improve patient compliance.
Journal of Developing Drugs, May 11, 2016
Tropical Journal of Pharmaceutical Research
Purpose: To develop modified hard gelatin capsules (MHGCs) for colon-specific delivery of hydroge... more Purpose: To develop modified hard gelatin capsules (MHGCs) for colon-specific delivery of hydrogel-based piroxicam microparticles. Methods: Solvent evaporation technique was adopted for the microencapsulation of piroxicam using liquid paraffin (PL.MPs) and soybean oil (PS.MPs) which were subsequently encapsulated in MHGCs (water-impervious). Anti-inflammatory and in vitro dissolution studies were conducted on the unencapsulated microparticles (MPs). Furthermore, in vitro colon-specific sequential drug release from impervious capsules was carried out for 2 h at pH 1.2 and 3 h in 6.8, and ≥ 5 h in 7.4, to simulate drug release in the stomach, small intestine, and colon environment, respectively. Differential scanning calorimetry (DSC) analysis was also conducted on the formulations. Results: Edema inhibition of PL.MPs and PS.MPs were within the range of 51.0 – 64.0 and 58.0 – 69.0 %, respectively. In vitro colon-specific drug dissolution studies revealed absence, minimal, and highest ...
Bio-Research
The mouth is a vital route of drug administration with over 84 % of all medicines reportedly admi... more The mouth is a vital route of drug administration with over 84 % of all medicines reportedly administered through it. The gastrointestinal system is equally imbued with a lot of adaptive features that make the oral route even more conducive for systemic drug delivery. The usefulness of the oral route is, however challenged by the existence of numerous absorption barriers which limit the effective absorption and delivery of drugs to their target sites in the body systems. Understanding these adaptive attributes, systemic barriers and available strategies for overcoming such barriers will not only be helpful in drug development and design but also useful to the formulation scientists desirous of optimizing drug delivery. The objective of this work was to review the gastrointestinal route of drug administration with respect to some biochemical and physio-anatomic features that impede or enhance drug absorption and to highlight current strategies that have been deployed to achieve optim...
The main aim of the present investigation was to develop sustained release (SR) floating drug del... more The main aim of the present investigation was to develop sustained release (SR) floating drug delivery system (FDDS) of sodium salicylate using k-carrageenan as the sustained release matrix. Varying w/w concentration ratios of drug and polymer dispersion ranging from 1:0 to 1:1 were selected from the preliminary trials for this investigation made from batches granulated with isopropyl alcohol containing, in addition, the same w/w concentration of: PVP K30; magnesium stearate and talc. Equal concentrations of citric acid and optimum concentration of sodium bicarbonate in the various batches were used to induce the generation of CO 2. The physical properties of the various matrices were studied. The in vitro buoyancy lag time (BLT), total floating time (TFT) and in vitro drug release of the tablets were studied in 0.1 N HCl. The results show that BLT ranged from 50 to 55 s, while the TFT were significantly higher than 12 h (p < 0.05) for most batches. Results of in vitro release sh...
Application of ĸ-carrageenan as a sustained release matrix in floating tablets containing sodium ... more Application of ĸ-carrageenan as a sustained release matrix in floating tablets containing sodium salicylate
Indian Journal of Pharmaceutical Sciences, 2013
The aim of this work was to formulate Alstonia boonei dried stem bark powder into tablets by wet ... more The aim of this work was to formulate Alstonia boonei dried stem bark powder into tablets by wet granulation method using acacia, gelatine and sodium carboxymethyl cellulose as binders at concentrations of 1, 2, 4 and 8% w/w. The phytochemistry of the stem bark of Alstonia boonei was evaluated. The micromeritic properties of the granules prepared were studied. The tablets were evaluated using the necessary official and unofficial tests. The results of the phytochemical analysis showed that alkaloids, tannins, steroids, saponins, glycosides, flavonoids and terpenoids were present while anthroquinones and acidcompounds were absent. Micromeritic studies showed that Alstonia boonei granules had good flowability. The formulated tablets complied with British Pharmacopoeial specification for weight uniformity, hardness (≥5 kgf) and tablet friability (<1%). For disintegration test, tablets formulated with gelatine and acacia at concentrations of 1, 2 and 4% w/w complied with Pharmacopoei...
Transylvanian Review, 2016
Aim/Background: Greater than 40 % of new chemical moieties are poorly water soluble drug. This le... more Aim/Background: Greater than 40 % of new chemical moieties are poorly water soluble drug. This leads to poor dissolution, absorption and bioavailability issues. To tackle this problem, artemether-loaded self microemulsifying drug delivery system (SMEDDS) was formulated and some in vitro and in vivo properties evaluated. Materials and Methods: Solubility studies and pseudoternary phase diagrams were done. Optimized-SMEDDS batches were formulated and loaded with 40, 50 and 55 mg of the drug. Pre/post formulation visual isotropicity, emulsification time, refrigeration cycle, centrifugation, aqueous dilution, and globule size analysis, were carried out. The in vitro release profile of the drug was done in simulated gastric fluid (SGF) without pepsin (pH, 1.2) and stimulated intestinal fluid (SIF) without pancreatin (pH, 6.8) respectively. An in vivo antimalarial activity of the artemether was carried out using 25 mice of 5 mice per group: SMEDDS-treated group (test group), chloroquine-t...
Objective: The decline in the use of herbal medicine especially in the Western world may be due t... more Objective: The decline in the use of herbal medicine especially in the Western world may be due to lack of readily available market brand formulations and the fact that most herbal remedies are taken as tea, decoctions and infusions. The taste of some of these herbal drugs is not palatable, and some have unpleasant odour and colour hence, the need to formulate these drugs in form of encapsulated dosage forms. The objective of the work was to formulate solid lipid microparticles (SLMs) loaded with the methanolic extract of Garcinia kola seed. Methods: The SLMs containing 1 and 3 % of Garcinia kola seed extract were formulated using fat from Capra hircus and Phospholipon ® 90H (3:1). The particle morphology and size, encapsulation efficiency (EE%), pH, in vitro release and the inhibition zone diameter (IZD) of the SLMs were determined. Results: The results showed that the extract was very bitter while, the encapsulated G. kola had slight bitter taste. The pH remained in the acidic reg...
Summary: Orally administered metronidazole often requires just a fraction of the administered dos... more Summary: Orally administered metronidazole often requires just a fraction of the administered dose for optimum local activity in the colon. Any formulation design that can target drug to the colon may require dose reduction while improving therapeutic activity. Colon targeted drug delivery achieves this fit. The objective of this work therefore was to evaluate the in vitro effect of, the percentage of surface area of capsule surface coated with Landolphia owariensis latex (LOL), particle size of granules, and %w/w of matrix former (methylcellulose) on the release of metronidazole from coated hard gelatine capsules for possible delivery to the colon. Metronidazole granules were prepared by the wet granulation technique and appropriately encapsulated prior to primary coating of capsule with Eudragit ® L-100 and secondary coating with LOL. Capsules having primary coating of Eudragit ® L-100 were coated with LOL atop 50% or 85% capsule surface. In vitro drug release was carried out sequ...
Objectives: To prepare and evaluate sustained release artemether-loaded SLMs based on SRMS Materi... more Objectives: To prepare and evaluate sustained release artemether-loaded SLMs based on SRMS Material and methods: SRMS, consisting of mixtures of Phospholipon ® 90H (P90H) and Softisan ® 154 (1:1, 2:1 and 1:2) were formulated and characterized using differential scanning calorimetry (DSC). The SRMS were used to formulate artemether-loaded SLMs by melt homogenization. The SLMs were characterized based on particle size and morphology, pH stability, encapsulation efficiency (EE%) and loading capacity. In vitro release was carried out in simulated intestinal fluid (SIF, pH 7.5). Results: Thermograms of the SRMS (1:1, 2:1 and 1:2) showed sharp endothermic peaks at 65.5, 64.4 and 62.3 o C respectively. Maximum EE% of 70.00 ± 1.50 % was obtained for SLMs formulated with SRMS 1:1 and 1 % artemether. Loading capacity ranged from 5.67 to 17.90 g drug/100 g lipid. In vitro release showed about 80 to 84 % drug release at 7 h. Particle size of artemether-loaded SLMs ranged from 18.60 ± 0.09 to 34...
Journal of Pharmaceutics and Therapeutics
Objective: To formulate extended release gentamicin-entrapped lipospheres using natural lipids fr... more Objective: To formulate extended release gentamicin-entrapped lipospheres using natural lipids from Irvingia wombolu (IWF) and Moringa oleifera seed (MO) popularly known as Ben oil. Methods: Different lipid combinations including IWF and Phospholipon 90H (P90H) and IWF and MO were employed in the formulation of lipospheres. The formulations were analysed for particle size, encapsulation efficiency (EE), pH stability and antimicrobial studies amongst other tests. Also the in vitro release properties were studied in Phosphate buffer pH 7.2. Results: High EE of up to 90 % were obtained for the various LM combinations. The pH was stable over 30 days and the formulations showed about 93 % release of gentamicin at 12 h. Lipospheres formulated with MO matrices showed synergism in the microbial inhibition than other formulations. Conclusion: Natural lipids from Irvingia wombolu and Moringa oleifera seed could be used in formulating oral extended release gentamicin lipospheres.
Journal of Current Pharma Research
The aims of the study were to evaluate the antibacterial properties of Garcinia kola seed extract... more The aims of the study were to evaluate the antibacterial properties of Garcinia kola seed extractloaded lipospheres and to mask its bitter taste in order to improve palatability and enhance patients' acceptability of this herbal drug. The methanolic extract of Garcinia kola seed-loaded lipospheres were prepared using lipid matrix consisting of mixture of goat fat and Phospholipon ® 90H (3:1). The lipospheres were characterized by determining the organoleptic properties, particle size and morphology, pH and encapsulation efficiency (EE%). The antibacterial properties were also determined. The results showed that the lipospheres had a taste masking effect on the extract. The particles sizes of the lipospheres were within the acceptable range for lipospheres. Maximum EE% of 92.2, 93.6 and 95.7 % were obtained for the lipospheres loaded with 5, 1 and 3 % of extract respectively. The pH remained in the neutral range at day one, but reduced to acidic pH at 7 and 30 days. The lipospheres had Inhibition zone diameter (IZD) of about 20 ± 0.91 mm against Staphylococcus aureus but, had no action against Escherichia coli. The reference drug (tetracycline) however, had significantly higher IZD of both organisms than the Garcinia kola seed extract-loaded lipospheres (p < 0.05). Garcinia kola seed-loaded lipospheres had good antimicrobial properties, improved palatability and could be used to enhance patient's compliance to this herbal drug.
Journal of Developing Drugs, May 11, 2016
African Journal of Biotechnology, Dec 31, 2013
Solidified reverse micellar solutions (SRMS) are reverse micelles containing lecithin and a trigl... more Solidified reverse micellar solutions (SRMS) are reverse micelles containing lecithin and a triglyceride, for example, SOFTISAN ® 142, which is hydrogenated coco glyceride. SRMS transform into a lamellar mesophase after melting on contact with water; this transformation enables controlled release of solubilized drugs. They offer potentials for sustained drug delivery of both hydrophilic and lipophilic drugs. SRMS have the advantage of providing more flexibility in controlling the drug release and protecting the encapsulated ingredients from chemical degradation. SRMS based systems influence the absorption of active ingredients through different mechanisms to modify the release of active ingredients, and improve drugs bioavailability. The types of SRMS-based drug delivery systems include solid lipid nanoparticles (SLN), solid lipid microparticles (SLM), tablets and suppositories amongst others. The work exhaustively reviews the advances in SRMS based carriers. Its formulation methods, characterisation and delivery systems were discussed in details.
African Journal of Pharmacy and Pharmacology, Dec 29, 2013
Recently, advances in pharmaceutical research is focused on new delivery systems utilizing new de... more Recently, advances in pharmaceutical research is focused on new delivery systems utilizing new devices to achieve modification of delivery time, targeting, as well as improve the in vivo solubility and hence bioavailability of poorly soluble drugs. Lipid based drug delivery systems (LDDS) consists of diverse group of formulations, each consisting of varying functional and structural properties that are amenable to modifications achieved by varying the composition of lipid excipients and other additives. LDDS has evolved, overtime, from micro-to nano-scale enhancing the efficacy and therapeutic application of these systems. LDDS are accepted, proven, commercially viable strategies for formulating challenging pharmaceutical molecules and can be tailored to meet a wide range of product requirements. Generally, most lipid drug delivery systems used as drug carriers have high stability, high carrier capacity, feasibility of incorporating both hydrophilic and hydrophobic substances and feasibility of variable routes of administration, including oral, topical, parenteral and pulmonary routes. LDDS can also be designed to allow modified drug release from matrices. LDDS could be broadly grouped into four: solid lipid particulate dosage forms, emulsion based systems, solid lipid tablets, and vesicular systems. Modifications from these four types include: lipospheres, solid lipid nanoparticles (SLNs), nano structured lipid carriers (NLC), lipid drug conjugate nanoparticles (LDC), self emulsifying formulations (SEFs), pickering emulsions, dry emulsions, micro and nano-emulsions, solidified reverse micellar solution (SRMS) based tablets, liposomes, herbosomes, cryptosomes and transferosomes amongst others. This work exhaustively reviewed the advances in LDDS and also drew comparison between the different types based on history, methods of manufacture, applications, advantages and disadvantages.
Bio Research Journal, Oct 16, 2022
The mouth is a vital route of drug administration with over 84 % of all medicines reportedly admi... more The mouth is a vital route of drug administration with over 84 % of all medicines reportedly administered through it. The gastrointestinal system is equally imbued with a lot of adaptive features that make the oral route even more conducive f or systemic drug delivery. The usef ulness of the oral route is, however challenged by the existence of numerous absorption barriers which limit the ef f ective absorption and delivery of drugs to their target sites in the body systems. Understanding these adaptive attributes , systemic barriers, and available strategies f or overcoming such barriers will not only be helpf ul in drug development and design but also usef ul to the f ormulation scientists desirous of optimizing drug delivery. The objective of this work was to review the gastrointestinal route of drug administration with respect to some biochemical and physio-anatomic f eatures that impede or enhance drug absorption and to highlight current strategies that have been deployed to achieve optimum per oral drug delivery. The current review reveals the emerging roles of nanocarriers in oral drug delivery. Polymeric nanocarriers enhance the solubility, targeting and saf ety prof iles of many important pharmacological agents. Novel systems that of f er protection against gastro enzymes and as such, promote oral ad ministration of biologicals are being widely investigated. Mechanical, magnetic, and acoustic energyinduced membrane perturbation are other delivery options receiving research attentions. It may be concluded that, with the avalanche of research ef f orts in the area, the oral route will maintain its prominence among other routes of drug administration.
African Journal of Pharmacy and Pharmacology, Jun 29, 2013
The purpose of this study was to evaluate the antioxidant properties of Vitis vinifera juice extr... more The purpose of this study was to evaluate the antioxidant properties of Vitis vinifera juice extract (grape) in rifampicin suspensions and to compare with that of ascorbic acid. Grape juice was extracted and used as antioxidant in both pure sample and commercial reconstituted samples of rifampicin. The rate of drug degradation was determined by spectroscopic method in a time dependent manner. Also, the antioxidant property of grape juice was compared with that of ascorbic acid. Phytochemical screening of the constituents in grape juice extract was carried out according to standard methods. The results revealed that rifampicin dispersions containing ascorbic acid (batches A1 to A5) showed significantly higher stability and had higher amount of drug remaining over time than the control (batch A6) containing no antioxidant (p < 0.05). However, the results revealed that grape fruit juice extract had higher antioxidant properties than the ascorbic acid (p < 0.05) in rifampicin dispersions. The results also indicated that increase in amount of both antioxidants significantly reduced the rate of drug degradation through oxidation, thereby causing a corresponding increase in the amount of rifampicin remaining over time. Grape juice extract contain alkaloids, carbohydrates, saponins, reducing sugars, steroids, tannins, proteins, flavonoids, resins, oils, terpenoids and acid compounds. Glycosides were however not found in the juice extract. Therefore, grape fruit juice extract could be used as a natural antioxidant in rifampicin suspensions.
Journal of Drug Delivery Science and Technology, 2014
The aims of the study were to investigate the excipient potentials of two natural lipids from Irv... more The aims of the study were to investigate the excipient potentials of two natural lipids from Irvingia wombolu and Moringa oleifera in rifampicin-loaded lipospheres. Lipospheres were formulated using different ratios of structured lipid matrices comprising of Phospholipon 90H (P90H) and Irvingia wombolu fats (IWF), and Phospholipon 90G (P90G) and Moringa oil (MO), respectively. Different in vitro test were studied including the particle size, encapsulation efficiency (EE), stability of formulations in simulated gastric fluid (SGF, pH 1.2), in vitro drug release, minimum inhibitory concentrations (MIC) and in vivo release. Results showed spherical particles within the size limit for lipospheres. Highest EE of 91.6 % was obtained. The lipospheres protected rifampicin against acidic degradation in the stomach (p < 0.05) and exhibited in vitro release of about 71.9 % at 12 h. In vivo release showed that the formulations had significantly higher in vivo absorption than the pure rifampicin sample (p < 0.05) and also showed higher antibacterial properties against Bacillus subtilis and Escherichia coli (p < 0.05). Rifampicin-loaded lipospheres had sustained release properties and could be used for once daily administration.
African Journal of Pharmacy and Pharmacology, Nov 22, 2013
The aim of the present study was to evaluate in vivo the anti-inflammatory, antinociceptive and u... more The aim of the present study was to evaluate in vivo the anti-inflammatory, antinociceptive and ulcerogenic properties of indomethacin tablets based on solidified reverse micellar solution (SRMS). SRMS consisting of mixtures of phospholipid (Phospholipon ® 90H) and triglyceride (Softisan ® 154) were prepared in the ratios of 1:1, 2:1 and 1:2, respectively. SRMS based tablets containing 75 mg of indomethacin each were prepared using validated plastic mould. The physicochemical properties of the tablet formulations were studied using both official and unofficial tests. Anti-inflammatory, analgesic/antinociceptive and ulcerogenic properties of indomethacin tablets based on SRMS were studied. The results showed that the physicochemical properties of the tablet formulations were significantly affected by the composition/ratio of the lipid matrix used. The softening time in SIF ranged from 53.7 ± 0.5 to 102.6 ± 0.5 min. Results of analgesic/antinociceptive properties showed that indomethacin tablets formulated with the SRMS 1:1 had an increase in pain reaction time at 7 h significantly (p < 0.05) different from the results exhibited by tablets formulated with the lipid matrices, SRMS 1:2 and 2:1 and the reference, which showed a decrease in pain reaction time at 7 h. Indomethacin tablets based on SRMS had good anti-inflammatory properties and also inhibited the ulcerogenicity of indomethacin by 70 to 80%. Therefore, indomethacin tablets based on SRMS could be used for improved oral bioavailability of indomethacin and to enhance patient's compliance due to inhibition of gastric irritation effect of this drug.
African Journal of Pharmacy and Pharmacology, Apr 22, 2013
The objectives of the present study were to formulate sustained release pyridoxine hydrochloride ... more The objectives of the present study were to formulate sustained release pyridoxine hydrochloride capsules and to study the effect of propylene glycol co-solvents on the in vitro properties of the capsules. All batches of formulations were made with fixed concentrations of binder-disintegrants, diluents and equal load of active pharmaceutical ingredient. The granules were prepared by wet granulation using propylene glycol water co-solvent as the wetting agent, sodium carboxymethylcellulose (SCMC) and maize starch were used as binder-disintegrant and kaolin was used as the diluents. The micromeritic properties of the granules were analysed by direct and indirect methods. The granules were encapsulated in hard gelatin capsule No. 1. The capsule weight uniformity, disintegration time and drug content were determined. In vitro dissolution test was performed in 0.1 N HCl, simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.2). The results showed that the particles size of granules ranged from 245 to 259 µm and had good flowability. The capsules complied with British Pharmacopoeia (BP) requirement for capsule weight uniformity. The drug content was within 90 to 110% of the average values. The results of in vitro drug release in SGF (pH, 1.2) showed that the release of pyridoxine hydrochloride was very slow and was significantly (P < 0.05) lower than the release in 0.1 N HCl and in SIF (pH, 7.2), respectively. Therefore, pyridoxine hydrochloride sustained release capsules could be formulated with kaolin as the diluent and propylene glycol co-solvent as the moistening agent in order to reduce the frequency of administration of this drug and improve patient compliance.
Journal of Developing Drugs, May 11, 2016
Tropical Journal of Pharmaceutical Research
Purpose: To develop modified hard gelatin capsules (MHGCs) for colon-specific delivery of hydroge... more Purpose: To develop modified hard gelatin capsules (MHGCs) for colon-specific delivery of hydrogel-based piroxicam microparticles. Methods: Solvent evaporation technique was adopted for the microencapsulation of piroxicam using liquid paraffin (PL.MPs) and soybean oil (PS.MPs) which were subsequently encapsulated in MHGCs (water-impervious). Anti-inflammatory and in vitro dissolution studies were conducted on the unencapsulated microparticles (MPs). Furthermore, in vitro colon-specific sequential drug release from impervious capsules was carried out for 2 h at pH 1.2 and 3 h in 6.8, and ≥ 5 h in 7.4, to simulate drug release in the stomach, small intestine, and colon environment, respectively. Differential scanning calorimetry (DSC) analysis was also conducted on the formulations. Results: Edema inhibition of PL.MPs and PS.MPs were within the range of 51.0 – 64.0 and 58.0 – 69.0 %, respectively. In vitro colon-specific drug dissolution studies revealed absence, minimal, and highest ...
Bio-Research
The mouth is a vital route of drug administration with over 84 % of all medicines reportedly admi... more The mouth is a vital route of drug administration with over 84 % of all medicines reportedly administered through it. The gastrointestinal system is equally imbued with a lot of adaptive features that make the oral route even more conducive for systemic drug delivery. The usefulness of the oral route is, however challenged by the existence of numerous absorption barriers which limit the effective absorption and delivery of drugs to their target sites in the body systems. Understanding these adaptive attributes, systemic barriers and available strategies for overcoming such barriers will not only be helpful in drug development and design but also useful to the formulation scientists desirous of optimizing drug delivery. The objective of this work was to review the gastrointestinal route of drug administration with respect to some biochemical and physio-anatomic features that impede or enhance drug absorption and to highlight current strategies that have been deployed to achieve optim...
The main aim of the present investigation was to develop sustained release (SR) floating drug del... more The main aim of the present investigation was to develop sustained release (SR) floating drug delivery system (FDDS) of sodium salicylate using k-carrageenan as the sustained release matrix. Varying w/w concentration ratios of drug and polymer dispersion ranging from 1:0 to 1:1 were selected from the preliminary trials for this investigation made from batches granulated with isopropyl alcohol containing, in addition, the same w/w concentration of: PVP K30; magnesium stearate and talc. Equal concentrations of citric acid and optimum concentration of sodium bicarbonate in the various batches were used to induce the generation of CO 2. The physical properties of the various matrices were studied. The in vitro buoyancy lag time (BLT), total floating time (TFT) and in vitro drug release of the tablets were studied in 0.1 N HCl. The results show that BLT ranged from 50 to 55 s, while the TFT were significantly higher than 12 h (p < 0.05) for most batches. Results of in vitro release sh...
Application of ĸ-carrageenan as a sustained release matrix in floating tablets containing sodium ... more Application of ĸ-carrageenan as a sustained release matrix in floating tablets containing sodium salicylate
Indian Journal of Pharmaceutical Sciences, 2013
The aim of this work was to formulate Alstonia boonei dried stem bark powder into tablets by wet ... more The aim of this work was to formulate Alstonia boonei dried stem bark powder into tablets by wet granulation method using acacia, gelatine and sodium carboxymethyl cellulose as binders at concentrations of 1, 2, 4 and 8% w/w. The phytochemistry of the stem bark of Alstonia boonei was evaluated. The micromeritic properties of the granules prepared were studied. The tablets were evaluated using the necessary official and unofficial tests. The results of the phytochemical analysis showed that alkaloids, tannins, steroids, saponins, glycosides, flavonoids and terpenoids were present while anthroquinones and acidcompounds were absent. Micromeritic studies showed that Alstonia boonei granules had good flowability. The formulated tablets complied with British Pharmacopoeial specification for weight uniformity, hardness (≥5 kgf) and tablet friability (<1%). For disintegration test, tablets formulated with gelatine and acacia at concentrations of 1, 2 and 4% w/w complied with Pharmacopoei...
Transylvanian Review, 2016
Aim/Background: Greater than 40 % of new chemical moieties are poorly water soluble drug. This le... more Aim/Background: Greater than 40 % of new chemical moieties are poorly water soluble drug. This leads to poor dissolution, absorption and bioavailability issues. To tackle this problem, artemether-loaded self microemulsifying drug delivery system (SMEDDS) was formulated and some in vitro and in vivo properties evaluated. Materials and Methods: Solubility studies and pseudoternary phase diagrams were done. Optimized-SMEDDS batches were formulated and loaded with 40, 50 and 55 mg of the drug. Pre/post formulation visual isotropicity, emulsification time, refrigeration cycle, centrifugation, aqueous dilution, and globule size analysis, were carried out. The in vitro release profile of the drug was done in simulated gastric fluid (SGF) without pepsin (pH, 1.2) and stimulated intestinal fluid (SIF) without pancreatin (pH, 6.8) respectively. An in vivo antimalarial activity of the artemether was carried out using 25 mice of 5 mice per group: SMEDDS-treated group (test group), chloroquine-t...
Objective: The decline in the use of herbal medicine especially in the Western world may be due t... more Objective: The decline in the use of herbal medicine especially in the Western world may be due to lack of readily available market brand formulations and the fact that most herbal remedies are taken as tea, decoctions and infusions. The taste of some of these herbal drugs is not palatable, and some have unpleasant odour and colour hence, the need to formulate these drugs in form of encapsulated dosage forms. The objective of the work was to formulate solid lipid microparticles (SLMs) loaded with the methanolic extract of Garcinia kola seed. Methods: The SLMs containing 1 and 3 % of Garcinia kola seed extract were formulated using fat from Capra hircus and Phospholipon ® 90H (3:1). The particle morphology and size, encapsulation efficiency (EE%), pH, in vitro release and the inhibition zone diameter (IZD) of the SLMs were determined. Results: The results showed that the extract was very bitter while, the encapsulated G. kola had slight bitter taste. The pH remained in the acidic reg...
Summary: Orally administered metronidazole often requires just a fraction of the administered dos... more Summary: Orally administered metronidazole often requires just a fraction of the administered dose for optimum local activity in the colon. Any formulation design that can target drug to the colon may require dose reduction while improving therapeutic activity. Colon targeted drug delivery achieves this fit. The objective of this work therefore was to evaluate the in vitro effect of, the percentage of surface area of capsule surface coated with Landolphia owariensis latex (LOL), particle size of granules, and %w/w of matrix former (methylcellulose) on the release of metronidazole from coated hard gelatine capsules for possible delivery to the colon. Metronidazole granules were prepared by the wet granulation technique and appropriately encapsulated prior to primary coating of capsule with Eudragit ® L-100 and secondary coating with LOL. Capsules having primary coating of Eudragit ® L-100 were coated with LOL atop 50% or 85% capsule surface. In vitro drug release was carried out sequ...
Objectives: To prepare and evaluate sustained release artemether-loaded SLMs based on SRMS Materi... more Objectives: To prepare and evaluate sustained release artemether-loaded SLMs based on SRMS Material and methods: SRMS, consisting of mixtures of Phospholipon ® 90H (P90H) and Softisan ® 154 (1:1, 2:1 and 1:2) were formulated and characterized using differential scanning calorimetry (DSC). The SRMS were used to formulate artemether-loaded SLMs by melt homogenization. The SLMs were characterized based on particle size and morphology, pH stability, encapsulation efficiency (EE%) and loading capacity. In vitro release was carried out in simulated intestinal fluid (SIF, pH 7.5). Results: Thermograms of the SRMS (1:1, 2:1 and 1:2) showed sharp endothermic peaks at 65.5, 64.4 and 62.3 o C respectively. Maximum EE% of 70.00 ± 1.50 % was obtained for SLMs formulated with SRMS 1:1 and 1 % artemether. Loading capacity ranged from 5.67 to 17.90 g drug/100 g lipid. In vitro release showed about 80 to 84 % drug release at 7 h. Particle size of artemether-loaded SLMs ranged from 18.60 ± 0.09 to 34...
Journal of Pharmaceutics and Therapeutics
Objective: To formulate extended release gentamicin-entrapped lipospheres using natural lipids fr... more Objective: To formulate extended release gentamicin-entrapped lipospheres using natural lipids from Irvingia wombolu (IWF) and Moringa oleifera seed (MO) popularly known as Ben oil. Methods: Different lipid combinations including IWF and Phospholipon 90H (P90H) and IWF and MO were employed in the formulation of lipospheres. The formulations were analysed for particle size, encapsulation efficiency (EE), pH stability and antimicrobial studies amongst other tests. Also the in vitro release properties were studied in Phosphate buffer pH 7.2. Results: High EE of up to 90 % were obtained for the various LM combinations. The pH was stable over 30 days and the formulations showed about 93 % release of gentamicin at 12 h. Lipospheres formulated with MO matrices showed synergism in the microbial inhibition than other formulations. Conclusion: Natural lipids from Irvingia wombolu and Moringa oleifera seed could be used in formulating oral extended release gentamicin lipospheres.
Journal of Current Pharma Research
The aims of the study were to evaluate the antibacterial properties of Garcinia kola seed extract... more The aims of the study were to evaluate the antibacterial properties of Garcinia kola seed extractloaded lipospheres and to mask its bitter taste in order to improve palatability and enhance patients' acceptability of this herbal drug. The methanolic extract of Garcinia kola seed-loaded lipospheres were prepared using lipid matrix consisting of mixture of goat fat and Phospholipon ® 90H (3:1). The lipospheres were characterized by determining the organoleptic properties, particle size and morphology, pH and encapsulation efficiency (EE%). The antibacterial properties were also determined. The results showed that the lipospheres had a taste masking effect on the extract. The particles sizes of the lipospheres were within the acceptable range for lipospheres. Maximum EE% of 92.2, 93.6 and 95.7 % were obtained for the lipospheres loaded with 5, 1 and 3 % of extract respectively. The pH remained in the neutral range at day one, but reduced to acidic pH at 7 and 30 days. The lipospheres had Inhibition zone diameter (IZD) of about 20 ± 0.91 mm against Staphylococcus aureus but, had no action against Escherichia coli. The reference drug (tetracycline) however, had significantly higher IZD of both organisms than the Garcinia kola seed extract-loaded lipospheres (p < 0.05). Garcinia kola seed-loaded lipospheres had good antimicrobial properties, improved palatability and could be used to enhance patient's compliance to this herbal drug.