Browsing by Author "Abioye, A. O."
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Item Metadata only Antimicrobial activity of Litsea cubeba, Rosmarinus officinalis and Citrus lemon essential oils against five skin-infection related pathogens(Phytochemical Society of Europe, 2017-04) Ogbechie, A.; Abioye, A. O.; Shen, Jinsong; Laird, KatieAxillary odour, athlete’s foot, eczema and infected wounds, are all conditions that are caused by organisms such as Staphylococcus aureus, Staphylococcus epidermidis, Trichophyton rubrum, Escherichia coli and Pseudomonas aeruginosa. Antimicrobial textiles such as wound dressings may go some way in combating such diseases. It is becoming increasingly important to consider the environment when selecting consumer goods such as antimicrobial textiles, problems such as toxicity and other health hazards have led to processing of textiles by more eco-friendly methods. Thus, Essential oils (EOs) may be a natural alternative to chemical based antimicrobials1. Ten EOs were screened by the disc diffusion method against S. aureus, P. aeruginosa, E. coli, S. epidermidis and T. rubrum. The Minimum Inhibitory Concentrations (MICs), Minimum Bactericidal Concentrations (MBCs) and Fractional Inhibitory Concentrations (FICs) of Litsea cubeba (Litsea), Citrus limon (Lemon) and Rosmarinus officinalis (Rosemary) EOs were determined using the microdilution method. Litsea oil was most effective, with an average zone of inhibition (ZoI) of 47 mm, 20 mm, 53 mm, 43 mm and 90mm (complete inhibition) against S. aureus, P. aeruginosa, E. coli, S. epidermidis and T. rubrum respectively. S. aureus was the most susceptible bacterial organism, being inhibited by all EOs tested; P. aeruginosa in turn was the most resistant to the EOs. Litsea EO gave lowest MICs and MBCs against all microorganisms, with the lowest MIC and MBC observed against S. epidermidis (0.60 and 1.30 mg/ml respectively). The organisms were least susceptible to Lemon EO, with generally higher MICs and MBCs. Further investigations are underway to determine synergistic activity between the EOs and the chemical components responsible for the activity. References: 1. Kavanaugh N.L. & Ribbeck K., 2012. Selected antimicrobial essential oils eradicate Pseudomonas spp. and Staphylococcus aureus biofilms. Applied and Environmental Microbiology, 78, 4057-4061.Item Metadata only Antimicrobial Activity of Litsea, Lemon and Rosemary Essential Oils and Their Combinations Against Healthcare and Sportswear Infection-Related Pathogens(American Society of Microbiology, 2017-02) Ogbechie, A.; Abioye, A. O.; Shen, Jinsong; Laird, KatieAxillary odour, athlete’s foot, eczema and infected wounds, are all conditions that are caused by organisms such as Staphylococcus aureus, Staphylococcus epidermidis, Trichophyton rubrum, Escherichia coli and Pseudomonas aeruginosa. Antimicrobial textiles such as wound dressings if rendered antimicrobial may go some way in combating such diseases and it is becoming increasingly important to consider the environment when selecting consumer goods such as textiles, as problems such as toxicity and other health hazards have led to processing of textiles by more eco-friendly methods. Essential oils (EOs) are now being explored as natural antimicrobials (Kavanaugh and Ribbeck 2012). Ten EOs were screened by the disc diffusion method against S. aureus, P. aeruginosa, E. coli, S. epidermidis and T. rubrum. The Minimum Inhibitory Concentrations (MIC), Minimum Bactericidal Concentrations (MBC) and Fractional Inhibitory Concentrations (FICs) of Litsea, Lemon and Rosemary EOs were determined using the microdilution method. Litsea oil was most effective, with an average zone of inhibition (ZoI) of 47 mm, 20 mm, 53 mm, 43 mm and 90 mm (complete inhibition) against S. aureus, P. aeruginosa, E. coli, S. epidermidis and T. rubrum respectively. Lemon and Rosemary were the only other EOs effective against P. aeruginosa (ZoI 21 and 24 mm respectively), as well as inhibiting the other microorganisms. S. aureus was the most susceptible bacterial organism, being inhibited by all EOs tested; P. aeruginosa in turn was the most resistant. The MIC and MBC of Litsea, Lemon and Rosemary EOs (the most effective EOs against all tested organisms) were determined. Litsea EO gave the lowest MICs and MBCs against all microorganisms, ranging from 0.6-10.4 mg/ml and 1.2-20.8 mg/ml respectively. The organisms were least susceptible to Lemon EO with MIC and MBC concentrations of 10.1-40.4 mg/ml and 20.2-40.4 mg/ml respectively. Synergistic interactions between the 3 EOs were observed for E. coli only (FIC index = 0.5); for the other organisms, interactions were either antagonistic or antimicrobial but not synergistic. Essential oils are promising natural antimicrobials which can inhibit the growth of Gram-positive and Gram-negative bacteria as well as dermatophytes; and therefore, are good microencapsulation core material candidates for use in functional antimicrobial textiles that are eco-friendly and may effectively be used to alleviate skin conditions and malodour.Item Metadata only Antimicrobial and toxicological studies of Epa-Ijebu, a "wonder-cure" concoction used in South West Nigeria.(2009) Adeleye, A. I.; Ayolabi, C. I.; Ejike, L. N.; Abioye, A. O.; Omonigbeyin, E. A.Item Metadata only Controlled Electrostatic Self-Assembly of Ibuprofen-Cationic Dextran Nanoconjugates Prepared by low Energy Green Process – a Novel Delivery Tool for Poorly Soluble Drugs(Springer, 2014-12-20) Abioye, A. O.; Kola-Mustapha, A.Purpose: The direct effect of electrostatic interaction between ibuprofen and cationic dextran on the system-specific physicochemical parameters and intrinsic dissolution characteristics of ibuprofen was evaluated in order to develop drug-polymer nanoconjugate as a delivery strategy for poorly soluble drugs. Methods: Amorphous ibuprofen-DEAE dextran (Ddex) nanoconjugate was prepared using a low energy, controlled amphiphile-polyelectrolyte electrostatic self-assembly technique optimized by ibuprofen critical solubility and Ddex charge screening. Physicochemical characteristics of the nanoconjugates were evaluated using FTIR,DSC,TGA,NMR and SEM relative to pure ibuprofen. The in vitro release profiles and mechanism of ibuprofen release were determined using mathematical models including zero and first order kinetics; Higuchi; Hixson-Crowell and Korsmeyer-Peppas. Results: Electrostatic interaction between ibuprofen and Ddex was confirmed with FT-IR,1HNMR and 13CNMR spectroscopy. The broad and diffused DSC peaks of the nanoconjugate as well as the disappearance of ibuprofen melting peak provided evidence for their highly amorphous state. Low concentrations of Ddex up to1.0×10−6 g/dm3 enhanced dissolution of ibuprofen to a maximum of 81.32% beyond which retardation occurred steadily. Multiple release mechanisms including diffusion; discrete drug dissolution; anomalous transport and super case II transport were noted. Conclusion: Controlled assembly of ibuprofen and Ddex produced a novel formulation with potential extended drug release dictated by Ddex concentration.Item Metadata only Development of aqueous ternary nanomatrix films: a novel ‘green’ strategy for the delivery of poorly soluble drugs(Elsevier, 2016-11-05) Kola-Mustapha, A.; Armitage, David; Abioye, A. O.Aqueous polymeric films have potentially great values in drug development, particularly in controlled drug release and taste masking strategies. However the progressive polymer-particle coalescence that occurs randomly during film formation, curing and storage may render the film less permeable leading to erratic and unpredictable drug release profile. The focus of this study was to investigate the impacts of the in situ formation of polymer-drug nanoconjugate, at the interfacial nano-domains of two oppositely charged polymers, on the mechanism of film formation and to prepare aqueous ternary polymer-drug-polymer nanomatrix films as a novel green strategy for the delivery of ibuprofen, a model poorly soluble drug. Composite and Layer-by-Layer films were prepared by aqueous casting technique using the concept of combined polymer-drug self-assembly and polyelectrolyte complexation. The plain and drug-loaded nanomatrix films were characterized using SEM, AFM, FTIR, DSC and TGA. Ibuprofen formed spherical core-shell microstructures (4.55 - 9.73 μm) in gellan film. However in the presence of cationic dextran (Ddex), nanoconjugates (61.49±5.97 - 447.52±37.51 nm) were formed within the core of the film matrix. The composite films exhibited reduced tensile strength and lower elastic modulus with optimal conjugation efficiency of 98.14±1.19%, which correlates with higher dissolution efficiency (99.76%) compared to 47.37% in layer-by-layer (LbL) films, dictated by Ddex concentration. Generally, the mechanism of drug release was by Fickian diffusion, however anomalous transport or polymer relaxation was also observed at higher concentration of Ddex. This study demonstrated the potential application of aqueous drug-loaded nanomatrix films as controlled drug delivery strategy for ibuprofen, a model poorly soluble drug.Item Metadata only Ex vivo skin permeation and retention studies on chitosan–ibuprofen–gellan ternary nanogel prepared by in situ ionic gelation technique—a tool for controlled transdermal delivery of ibuprofen(Elsevier, 2015-05-19) Abioye, A. O.; Issah, S.; Kola-Mustapha, A.The chemical potentials of drug–polymer electrostatic interaction have been utilized to develop a novel ternary chitosan–ibuprofen–gellan nanogel as controlled transdermal delivery tool for ibuprofen. The ternary nanogels were prepared by a combination of electrostatic nanoassembly and ionic gelation techniques. The electrostatic and hydrophobic interactions as well as hydrogen bonding between ibuprofen and chitosan were confirmed with FTIR, while DSC, TGA and SEM confirmed the physical state, thermal and morphological characteristics, respectively. The ex vivo delivery of ibuprofen onto and across the skin was evaluated based on system specific drug release parameters such as steady state permeation rate, permeability coefficient, permeability enhancement ratio, skin/gel partition coefficient, diffusion coefficient, lag time and release rate constant and mechanisms of release were determined using mathematical models. Interaction between ibuprofen and chitosan produced new spherical eutectic nanoconjugates with remarkable decrease in particle size of ibuprofen from 4580 (length-to-breadth aspect ratio) to a minimum of 14.15 nm (324-times), and thermally stable amorphous characteristics. The nanogels exhibited significant elastic and pseudoplastic characteristics dictated by the concentration of chitosan with maximum swelling capacity of 775% w/w at 6.55 mM chitosan compared with 281.16 and 506.50% for plain gellan and control ibuprofen hydrogel, respectively. Chitosan enhanced the skin penetration, permeability and the rate of transdermal release of ibuprofen by a factor of 4, dictated by the extent of ibuprofen–chitosan ionic interaction and its concentration. The major mechanism of ibuprofen release through the pig skin was drug diffusion however drug partition and matrix erosion also occurred. It was evident that ternary nanogels are novel formulations with potential application in controlled transdermal delivery of ibuprofen.Item Metadata only Formulation studies on ibuprofen sodium–cationic dextran conjugate: effect on tableting and dissolution characteristics of ibuprofen(Taylor and Francis, 2015-03-31) Abioye, A. O.; Kola-Mustapha, A.The effect of electrostatic interaction between ibuprofen sodium (IbS) and cationic diethylaminoethyl dextran (Ddex), on the tableting properties and ibuprofen release from the conjugate tablet was investigated. Ibuprofen exhibits poor flow, compaction (tableting) and dissolution behavior due to its hydrophobic structure, high cohesive, adhesive and viscoelastic properties therefore it was granulated with cationic Ddex to improve its compression and dissolution characteristics. Electrostatic interaction and hydrogen bonding between IbS and Ddex was confirmed with FT-IR and DSC results showed a stepwise endothermic solid–solid structural transformation from racemic to anhydrous forms between 120 and 175 °C which melted into liquid form at 208.15 °C. The broad and diffused DSC peaks of the conjugate granules as well as the disappearance of ibuprofen melting peak provided evidence for their highly amorphous state. It was evident that Ddex improved the flowability and densification of the granules and increased the mechanical and tensile strengths of the resulting tablets as the tensile strength increased from 0.67 ± 0.0172 to 1.90 ± 0.0038 MPa with increasing Ddex concentration. Both tapping and compression processes showed that the most prominent mechanism of densification were particle slippage, rearrangement and plastic deformation while fragmentation was minimized. Ddex retarded the extent of dissolution in general, indicating potentials for controlled release formulations. Multiple release mechanisms including diffusion; anomalous transport and super case II transport were noted. It was concluded that interaction between ibuprofen sodium and Ddex produced a novel formulation with improved flowability, tableting and dissolution characteristics with potential controlled drug release characteristics dictated by Ddex concentration.Item Metadata only Impact of in situ granulation and temperature quenching on crystal habit and micromeritic properties of ibuprofen-cationic dextran conjugate crystanules(Elsevier, 2014-02) Abioye, A. O.; Kola-Mustapha, A.; Ruparelia, K. C.Item Metadata only In vitro kinetics of staphylococcal death in the stem bark extracts of Jatropha curcas Linn (Euphorbiaceae).(SENRA Academic Publishers, 2011) Abioye, A. O.; Adesisa, S. A.; Bamiro, S. B.; Okpako, E.Item Metadata only Novel green antimicrobial textile coatings for use in the healthcare and sport arenas(Society for Applied Microbiology, 2015) Ogbechie, A.; Abioye, A. O.; Shen, Jinsong; Laird, KatieAims To develop a novel green microencapsulation process for textile antimicrobial coating for the treatment of medical and sports related skin conditions and malodour, which will: • incorporate eco-friendly microcapsule wall materials (biodegradable polymers). • provide controlled release of the core material (essential oils). • exclude toxic substances. Methods and results The essential oils (EOs), Litsea, Lemon, Rosewood, Rosemary, Bergamot, Citronella, Sweet Orange, Bitter Orange, Peppermint and Thyme oil were screened by the disc diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus epidermidis. The most effective oil was Litsea oil, with an average zone of inhibition (ZoI) of 4.7 cm, 2.0 cm, 5.3 cm and 4.3 cm against S. aureus, P. aeruginosa, E. coli and S. epidermidis respectively. Lemon and Rosemary were the only other EOs which were found to be effective against P. aeruginosa with mean ZoI’s of 2.1cm and 2.4 cm respectively, as well as inhibiting the other 3 bacteria. S.aureus was the most susceptible organism being inhibited by all EOs; P. aeruginosa in turn was the most resistant to the EOs. Conclusions Litsea, Lemon and Rosemary EOs were the most inhibitory oils screened, therefore, the Minimum Inhibitory Concentrations (MIC) for these EOs will be determined and they will also be screened against the dermatophyte Trichophyton rubrum. Significance of study Increased awareness of the textiles industries’ impact on the environment, creates a need for new green processes using eco-friendly materials. The use of EOs as the core material of microcapsules in textile coatings, could lead to an effective textile coating which is not only green but also functional in the treatment of medical or sports related skin conditions. This innovative delivery system will go some way to alleviate infections such as athlete’s foot, body odour caused by sweat and atopic eczema.Item Metadata only The physicochemical and antibacterial properties of Ciproflaxacin-Mg2* complex.(2008) Adepoju-Bello, A. A.; Coker, H. A. B.; Eboka, C. J.; Abioye, A. O.; Ayoola, G. A.Item Open Access Polymer-drug nanoconjugate – an innovative nanomedicine: challenges and recent advancements in rational formulation design for effective delivery of poorly soluble drugs.(Bentham Science, 2016) Abioye, A. O.; Chi-Tangyie, George; Kola-Mustapha, A.; Ruparelia, K. C.; Beresford, Kenneth J. M.; Arroo, R. R. J.Abstract Background: Over the last four decades, the use of water soluble polymers in rational formulation design has rapidly evolved into valuable drug delivery strategies to enhance the safety and therapeutic effectiveness of poorly soluble drugs, particularly anticancer drugs. Novel advances in polymer chemistry have provided new generations of well defined polymeric architectures for specific applications in polymer-drug conjugate design. However, total control of crucial parameters such as particle size, molecular weight distribution, polydispersity, localization of charges, hydrophilic-lipophilic balance and non site-specific coupling reactions during conjugation has been a serious challenge. Objective: This review briefly describes the current advances in polymer-drug nanoconjugate design and various challenges hindering their transformation into clinically useful medicines. Method: Existing literature was reviewed. Results: This review provides insights into the significant impact of covalent and non-covalent interactions between drug and polymer on drug loading [or conjugation] efficiency, conjugate stability, mechanism of drug release from the conjugate and biopharmaceutical properties of poorly soluble drugs. The utility values and application of Quality by Design principles in rational design, optimization and control of the Critical Quality Attributes [CQA] and Critical Process Parameters [CPP] that underpin the safety, quality and efficacy of the nanoconjugates are also presented. Conclusion: It was apparent that better understanding of the physicochemical properties of the nanoconjugates as well as the drug-polymer interaction during conjugation process is essential to be able to control the biodistribution, pharmacokinetics, therapeutic activity and toxicity of the nanoconjugates which will in turn enhance the prospect of successful transformation of these promising nanoconjugates into clinically useful nanomedicines.Item Embargo Quantification of in situ granulation-induced changes in pre-compression, solubility, dose distribution and intrinsic in vitro release characteristics of ibuprofen–cationic dextran conjugate crystanules(Elsevier, 2014) Abioye, A. O.; Kola-Mustapha, A.; Chi-Tangyie, George; Iliya, SundayThe direct effect of intermolecular association between ibuprofen and diethylaminoethyl dextran (Ddex) and the novel ‘melt-in situ granulation–crystallization’ technique on the solubility, dose distribution, in vitro dissolution kinetics and pre-compression characteristics of the ibuprofen–Ddex conjugate crystanules have been investigated using various mathematical equations and statistical moments. The research intention was to elucidate the mechanisms of ibuprofen solubilization, densification and release from the conjugate crystanules as well as its dose distribution in order to provide fundamental knowledge on important physicochemical, thermodynamic and system-specific parameters which are key indices for the optimization of drug–polymer conjugate design for the delivery of poorly soluble drugs. The process of melt-in situ-granulation–crystallization reduced the solubility slightly compared with pure ibuprofen, however, the ibuprofen–Ddex conjugate crystanules exhibited increased ibuprofen solubility to a maximum of 2.47 Â 10 À1 mM (at 1.25 Â 10 À4 mM Ddex) and 8.72 Â 10 À1 mM (at 6.25 Â 10 À4 mM Ddex) at 25 and 37 C, respectively. Beyond these concentrations of Ddex ibuprofen solubility decreased steadily due to stronger bond strength of the conjugate crystanules. The enthalpy– entropy compensation plot suggests a dominant entropy-driven mechanism of solubilization. In the same vein, the addition of Ddex increased the rate and extent of in vitro ibuprofen release from the conjugate crystanule to 100% within 168 h at Ddex concentration of 1.56 Â 10 À4 mM, followed by a decrease with Ddex concentration. The conjugate crystanules exhibited controlled and extended- complete release profile which appeared to be dictated by the concentration of the Ddex and its strong affinity for ibuprofen. A comparison of the real experimental with the predicted data using artificial neural network shows excellent correlation between solubility and dissolution profiles (average error = 0.2348%). Heckel, Kawakita, Cooper–Eaton and Kuno equations were employed to determine the mechanism of densification during tapping process. Ddex in the crystanules consistently improved particle rearrangement in the order of 2.5–7 folds compared with pure ibuprofen and stabilized ibuprofen against fragmentation during tapping process. Primary and secondary particle rearrangements were the prominent mechanisms of densification while deformation and fragmentation did not occur. Lower concentrations of Ddex below its critical granular concentration (<6.25 Â 10 À4 mM) hindered plastic deformation and fragmentation, however, the summation of primary and secondary rearrangement parameters was greater than unity suggesting that the overall rearrangement of the conjugate crystanules cannot be explained exclusively by these two steps. This study has demonstrated the formulation of a novel ibuprofen–polymer conjugate which exhibited improved dose distribution and pre-compression characteristics as well as controlled and extended-complete release profiles – a potential drug delivery strategy for poorly soluble drugs.Item Metadata only Real-time monitoring of the mechanism of ibuprofen-cationic dextran crystanule formation using crystallization process informatics system (CryPRINS)(Elsevier, 2016-05-31) Abioye, A. O.; Tangyie Chi, G.; Simone, E.; Nagy, Z.One step aqueous melt-crystallization and in situ granulation was utilized to produce ibuprofen-cationic dextran [diethylaminoethyl dextran (Ddex)] conjugate crystanules without the use of surfactants or organic solvents. This study investigates the mechanism of in situ granulation-induced crystanule formation using ibuprofen (Ibu) and Ddex. Laboratory scale batch aqueous crystallization system containing in situ monitoring probes for particle vision measurement (PVM), UV–vis measurement and focused beam reflectance measurements (FBRM) was adapted using pre-defined formulation and process parameters. Pure ibuprofen showed nucleation domain between 25 and 64 °C, producing minicrystals with onset of melting at 76 °C and enthalpy of fusion (ΔH) of 26.22 kJ/mol. On the other hand Ibu-Ddex crystanules showed heterogeneous nucleation which produced spherical core-shell structure. PVM images suggest that internalization of ibuprofen in Ddex corona occurred during the melting phase (before nucleation) which inhibited crystal growth inside the Ddex corona. The remarkable decrease in ΔH of the crystanules from 26.22 to 11.96 kJ/mol and the presence of broad overlapping DSC thermogram suggests formation of ibuprofen-Ddex complex and crystalline-amorphous transformation. However Raman and FTIR spectra did not show any significant chemical interaction between ibuprofen and Ddex. A significant increase in dissolution efficiency from 45 to 81% within 24 h and reduced burst release provide evidence for potential application of crystanules in controlled drug delivery systems. It was evident that in situ granulation of ibuprofen inhibited the aqueous crystallization process. It was concluded that in situ granulation-aqueous crystallization technique is a novel unit operation with potential application in continuous pharmaceutical processing.Item Metadata only Thermodynamic Changes Induced by Intermolecular Interaction Between Ibuprofen and Chitosan: Effect on Crystal Habit, Solubility and In Vitro Release Kinetics of Ibuprofen(Springer, 2015-09-24) Abioye, A. O.; Armitage, R.; Kola-Mustapha, A.Purpose: The direct impact of intermolecular attraction between ibuprofen and chitosan on crystal behaviour, saturated solubility and dissolution efficiency of ibuprofen was investigated in order to expand the drug delivery strategy for ibuprofen. Methods: Amorphous nanoparticle complex (nanoplex) was prepared by controlled drug-polymer nanoassembly. Intermolecular attraction was confirmed with surface tension, conductivity measurements and FTIR spectroscopy. The nanoplex was characterized using DSC, TGA and SEM. The in vitro release kinetics and mechanism of drug release were evaluated using mathematical models. Results: The cmc of ibuprofen decreased significantly in the nanoplex (1.85 mM) compared with pure ibuprofen (177.62 mM) suggesting a remarkable affinity between the chitosan and ibuprofen. The disappearance of ibuprofen melting peak in the nanoplex and the broadened DSC endothermic peaks of the nanoplex indicate formation of eutectic amorphous product which corresponded to higher saturated solubility and dissolution velocity. Ibuprofen (aspect ratio 5.16±1.15) was converted into spherical nanoparticle complex with particle size of 14.96±1.162–143.17±17.5247 nm (36–345 folds reduction)dictated by chitosan concentration. Pure ibuprofen exhibited burst release while the nanoplexes showed both fast and extended release profiles. DE increased to a maximum(81.76± 2.1031%) with chitosan concentrations at 3.28×10–3 g/dm3, beyond which retardation occurred steadily. Major mechanism of drug release from the nanoplex was by diffusion however anomalous transport and super case II transport did occur. Conclusion: Ibuprofen-chitosan nanoplex exhibited combined fast and extended release profile dictated by chitosan concentration.This study demonstrated the potential application of drug-polymer nanoconjugate design in multifunctional regulated drug delivery.