scholarly works

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comparative photostability study of fancimef tablet and it's active ingredients
(1999) Oke, J. M.
fancimef tablet is one of the multi-component drugs recently introduced into malaria theraphy to combat the resistent strains of plasmodium parasite. Like most complex organic compounds, it is expectesd that the organic compounds in Fancimf tablet will absorb light spectra leading to its photodecomposition and all its attendant problems. In this study, a comparative photostability study of the Fancimf tablet and its active components was undertaken. The results obtained showed that the active ingredients of Fancimf tablet undergo photodecomposition in buffer solutions while the dry Fancimf tablet (powder) is photostable. Thus suggesting that Fancimf tablet is not susceptible to photodecomposition.
Evaluation of pharmaceutical and microbial qualities of some herbal medicinal products in South Western Nigeria
(Pharmacotherapy group, Faculty of Pharmacy, University of Benin, Benin City, 2007-03) Okunlola, A.; Adewoyin, B. A; Odeku, O. A.
Purpose: The aim of the present study was to investigate the pharmaceutical and microbial qualities of 21 different (of various dosage forms) Herbal Medicinal Products (HMPs) sourced from some traditional medicine sales outlets and retail pharmacy outlets in south western Nigeria. Method: The pharmaceutical qualities evaluated include tablet crushing strength, friability, disintegration time; density of the solutions and suspensions; particle size and angle of repose of the powders. Phytochemical tests were carried out to assess the class of compounds present in the formulations and the microbial quality of the products was also evaluated. Results: The results show that twelve (57.1 %) of the products had their manufacturing and expiry dates stated, nine (42.9%) products have been registered by NAFDAC and ten (47.6%) did not have their content stated but had their therapeutic claims indicated on the container. The tablet formulation (Product A) showed acceptable crushing strength and friability but failed the test for disintegration time. The angle of repose of the powder dosage forms were considerably high showing that the powders were highly cohesive and not free flowing. The microbial load of the products varied considerably. Ten (47.6%) of the samples were contaminated by E. coli, seven (33%) were contaminated by Salmonella, fifteen (71.4%) were contaminated by Staphylococcus aureus and twelve (57.1%) were contaminated by fungi. Conclusion: There is need for constant monitoring and control of the standards of herbal medicines available in the Nigerian market.
Comparative evaluation of starches obtained from dioscore species as intragranular tablet disintegrant
(Editions de Sante, 2008) Okunlola, A.; Odeku, O. A.
Starches from four Dioscorea species namely Dioscorea dumetorum (bitter yam), D. oppositifolia (Chinese yam), D. alata (water yam) and D. rotundata (white yam) have been evaluated as disintegrants in chloroquine phosphate tablet formulations in comparison with official corn starch. The mechanical and drug release properties of the tablets were assessed. The results showed that the ranking of the effectiveness of the starches as intragranular disintegrant was water > white > corn > Chinese> bitter. The disintegrant concentration had significant (p < 0.001) effects on the disintegrant efficiency. The four experimental starches compared favorably and in some cases showed better efficiency as intragranular disintegrant than corn starch and could be further developed for use in commercial tablet formulation.
Compressional characteristics and tableting properties of starches obtained from four dioscorea species
(2009) Okunlola, A; Odeku, O. A
The compressional characteristics and tableting properties of starches from four yam species namely Dioscorea dumetorum Pax (Bitter); Dioscorea oppositifolia L (Chinese); Dioscorea alata L.DIAL2 (Water) and Dioscorea rotundata Poir (White) were Investigated in comparison with corn starch. The physicochemical properties of the starches were evaluated using established methods while the compressional characteristics were analyzed using density measurements, and the Heckel and Kawakita equations. The properties of the tablets were assessed using Tensile strength (T), Brittle Fracture Index (BFI), Friability (F) and Disintegration Time (DT). The physicochemical properties of the starches varied considerably among the various species. The ranking for the mean yield pressure (Py) obtained from Heckel plots was Chinese > Bitter>Corn > White>Water while the ranking was the reverse for another pressure term, Pk, obtained from Kawakita plots. The ranking for T was Chinese > Bitter>Corn > White>Water. The T values were inversely related to Pk values. The ranking of DT was Bitter>Chinese>Corn>White> Water, while the ranking was reverse for BFI and F. Water and White yam starch tablets did not conform to the Pharmacopoeia requirements on friability (≤1%) while all the starch tablets except Bitter yam starch conformed to the requirements on disintegration (≤15minutes). Thus, the starches could be useful as excipients in tablet formulations.
Generic versus innovator: Analysis of the pharmaceutical qualities of paracetamol and ibuprofen tablets in the Nigerian market
(2009) Okunlola, A.; Adegoke, O. A.; Odeku, O. A.
The physicochemical equivalence of twenty-two brands of paracetamol and nine brands of ibuprofen tablets sourced from retail Pharmacy outlets in the Nigerian market to their respective innovator brands were investigated. The uniformity of weight, friability, crushing strength, disintegration and dissolution times and assay of active paracetamol ingredient were used as assessment parameters. All the brands of paracetamol and ibuprofen tablets complied with the official specifications for uniformity of weight. However, five brands of paracetamol failed the friability test, one brand of paracetamol and two brands of ibuprofen failed the disintegration test and three brands of paracetamol and four brands of ibuprofen failed the assay of active ingredients. The study shows that not all the brands of paracetamol and ibuprofen tablets are physico-chemically equivalent to their innovator brands. There is therefore the need for constant market surveillance to ascertain their compliance with official standards and equivalence to the innovator products.
Formulation factors affecting the binding properties of chinese yam (dioscorea oppositifolia) and corn starches
(Elsevier, 2009) Okunlola, A.; Odeku, O. A
Objective; The quantitative effects of formulation and processing variables affecting the binding properties of Chinese yam starch ( Dioscorea oppositifolia) in chloroquine phosphate tablet formulations have been investigated in comparison with com starch using a 23 factorial experimental design. Methods: Chinese yam starch, representing the "low" level, and com starch, representing the "high" level were used as binders at concentrations of 2. 5 % w/w and 10 % w/w in chloroquine phosphate tablet formulations. The mechanical properties of the tablets, measured by the tensile strength ( T ) and brittle fracture index ( BFI) as well as the release properties measured by the disintegration time (DT ) and dissolution time ( t80- time for 80 % drug release) , were used as assessment parameters. Results; The ranking of the individual coefficient values for the formulations on T was D > N » C , on BFI was N > D » C , on DT was D > N > C and on t80 was C > N > D while the ranking of the interaction coefficient on T was N-D > C-D » N-C, on BFI was N-D > N-C = C-D, on DT and t80 was N-C > N-D > C-D. Changing the binding agent from Chinese to corn starch, led to a decrease in T , DT and t80 but increase in BFI of the tablets. There were significant (P < 0 . 001) interactions between the nature of binder, N and the other two variables, C and D. Conclusion; The result showed that Chinese yam possessed stronger binding capacity than corn starch and could be useful as an alternative binder when tablets with high mechanical strength with minimal problems of lamination, and slow release are required.
Evaluation of freeze-dried pregelatinized Chinese yam (Dioscorea oppositifolia) starch as a polymer in floating gastroretenive metformin microbeads.
(2010) Okunlola, A.; Patel, R. P.; Odeku, O. A.
Pregelatinized Chinese yam (Dioscorea oppositifolia) starch has been evaluated as a polymer for the formulation of floating gastroretentive beads for the controlled delivery of metformin hydrochloride. Floating microbeads were prepared by the ionotropic gelation method using a blend of modified Chinese yam starch and sodium alginate at different ratios. Sodium bicarbonate was added as a gas-generating agent. The floating microbeads were characterized by SEM, DSC, FTIR analyses and the drug entrapment efficiency and floating ability was evaluated. Drug release was investigated using in vitro dissolution test and the results were fitted to various kinetic models to determine the mechanism(s) of release. Spherical, discrete and free flowing microbeads were obtained from the modified starch-alginate blends. Minimum lag time (< 20 s) was observed for the floating microbeads containing starch and buoyancy was maintained for 12 h. The release of MET from the floating microbeads appeared to be controlled by varying the starch to alginate polymer ratio. In general, the formulations followed diffusion and erosion mechanisms of drug release. The results suggest that modified Chinese yam starch-sodium alginate blend can be useful for the formulation of floating gastroretentive system for metformin hydrochloride
Effects of water yam and corn starches on the interacting variables influencing the disintegration of chloroquine phosphate tablets
(Medwell Journals, 2010) Okunlola, A.; Odeku, O. A.
The individual and interaction effects of nature (X) and concentration (Y) of disintegrant and the relative density (Z) on the mechanical and release properties of chlor-oquine phosphate tablets were studied using a 23 factorial experiment design. Water yam starch (low level) and corn starch (high level) were used as disintegrants at concentrations of 5.0 and 20.0% w/w .The mechanical properties were assessed using the Crushing Strength (CS) and Friability (F) and the release properties by the Disintegration Time (DT) and dissolution time (t80). Increasing the concentration of disintegrants and the relative density of tablets resulted in increase in CS but decrease in F, DT and t80. The ranking of the individual coefficient values was Z>X>Y for CS, Z>X>Y for F and DT and Y>X>Z for t80, while that for the interaction coefficient was X-Z>Y-Z>X-Y for CS, Y-Z>X-Z>X-Y for F, Y-Z>X-Y>X-Z for DT and t80. Changing the disintegrant from corn starch to water yam starch resulted in decrease in CS, DT and t80 but increase in F. The results show considerable interaction between the variables employed and suggest that water yam could be an alternative disintegrant to corn starch particularly where with faster disintegration and release are required.
PHARMACEUTICAL EQUIVALENCE AND COMPARATIVE BIOAVAILABILITY OF MULTISOURCED ARTESUNATE AND AMODIAQUINE TABLETS IN SOUTH WESTERN NIGERIA
(2011) ODUNFA, O. O.
Malaria is one of the most devastating parasitic diseases in the world and remains a major public health problem in Sub-Saharan Africa. First-line treatment of uncomplicated malaria includes the use of artesunate and amodiaquine. However, the existence of counterfeit and substandard artesunate and amodiaquine in the market may lead to therapeutic failures or development of resistance when consumed. The aim of the study was to examine the pharmaceutical equivalence of different brands of artesunate and amodiaquine tablets and, their bioavailability and tolerability when given as monotherapy and combination therapy. Fifteen brands of artesunate and five brands of amodiaquine tablets selected randomly were obtained from retail drug outlets in Ogun, Oyo and Lagos states in South western Nigeria and were subjected to various physicochemical tests including drug content, disintegration and dissolution times. The bioavailability after oral administration of single doses of artesunate (200mg), amodiaquine (600mg), their fixed combination (200mg/612.6mg), and non-fixed combination (200mg+600mg) as measured by high performance liquid chromatography of plasma samples and tolerability were compared. Sixteen healthy male volunteers aged between 18 and 45 years distributed into four groups received treatments at four different occasions in an open label, Latin square, 4-phase, cross-over study. Absorption was determined from area under the plasma drug concentration-time curves (AUC), peak plasma concentration (Cmax) reached and time taken to reach peak plasma concentration (Tmax). Impairment of absorption was indicated by at least one statistically significant parameter. Biochemical test was measured using serum albumin while body fat was derived from the body mass index. Data collected from physicochemical tests were evaluated using correlation and Chi square analyses while those of serum albumin and body fat, parent drugs and their main metabolites(dihydroartemisinnin and desethylamodiaquine) were assessed using logistic regression, Students’ t-test and ANOVA. Physicochemical tests revealed that 33.0% of the artesunate tablets and 80.0% of the amodiaquine tablets analyzed met compendial standards. Minimum absorption occurred when tablets were given as monotherapy and in combination. The bioavailability of artesunate when given in fixed combination with amodiaquine was lowered (Cmax ratio-76.4%, p<0.001) compared with monotherapy. Taking amodiaquine in fixed combination with artesunate markedly increased its bioavailability (AUC ratio-159.9%, p<0.001) when compared with monotherapy. However, concurrent administration of artesunate in non-fixed combination with amodiaquine reduced its bioavailability (Tmax ratio-209.7%, p<0.001) when compared with monotherapy. The bioavailability of amodiaquine was about twice as high when given in non-fixed combination (AUC ratio-195.4%, p<0.05) compared with monotherapy. Adverse events of concern were anaemia (81.25%), asthenia (62.5%) and neutropenia (25%). Asthenia was largely correlated with serum albumin in volunteers that took fixed dose combination (OR=9.3, p<0.05). Adverse effects were increased in volunteers that had higher body fat percentage (OR= 0.571, p>0.05). Pharmaceutically inequivalent and subpotent artesunate and amodiaquine tablets are in circulation in Southwestern Nigeria and this suggests the need for regulatory authorities to rigorously monitor their quality. There was severe impairment of rate and extent of absorption as a result of co-administration of the drugs. It is therefore recommended that artesunate should not be coadministered with amodiaquine in clinical setting.
Evaluation of starches obtained from four dioscorea species as binding agent in chloroquine phosphate tablet formulations
(Elsevier, 2011-01) Okunlola, A.; Odeku, O. A.
Starches obtained from four Dioscorea species namely Dioscorea dumetorum (Bitter), Dioscorea oppositifolia (Chinese), Dioscorea alata (Water), and Dioscorea rotundata (White) have been evaluated as binding agents in chloroquine phosphate tablet formulations in comparison with official corn starch. The compressional properties of the formulations were analyzed using density measurements and the Heckel and Kawakita equations. The mechanical properties of the tablets were assessed using tensile strength, brittle fracture index (BFI), and friability tests while the drug release properties of the tablets were assessed using disintegration and dissolution times. The results indicate that the four starches vary considerably in their physicochemical properties. The ranking for the tensile strength and the disintegration and dissolution times for the formulations was Chinese> Bitter > Corn> White > Water while the ranking was reversed for BFI and friability. The results suggest that Water, White, and Corn could be useful when faster disintegration time of tablets is desired while Chinese and Bitter could be more useful when bond strength is of concern and in minimizing the problems of lamination and capping in tablet formulation
Evaluation of mucoadhesive properties of native and modified starches of the root tubers of cocoyam (Xanthosoma sagittifolium)
(2011-09) Odeniyi, M. A.; Atolagbe, F. M.; Aina, O. O.; Adetunji, O.A.
The purpose of this study was to evaluate the bioadhesive properties of native and modified cocoyam (Xanthosoma sagittifolium) starches. The methods of modification were by pregelatinisation and acetylation. The starch particles were evaluated for characteristics like particle size, swelling ability, viscosity, and mucoadhesion. The mucoadhesive evaluation of the starches were done using the rotating cylinder methods in 0.1M HCl and Phosphate buffer (pH 6.8) to simulate the stomach and small intestine respectively. The mechanical properties of the compacted starches were determined using friability and crushing strength.The particles so prepared had irregular shape size ranged from 9.38 to 10.67mm. Mucoadhesion time was in the order Acetylated>Native>Pregelatinised starch in 0.1M HCl and Pregelatinised>Native>Acetylated starch in pH 6.8 Phosphate buffer. None of the severe signs such as appearance of epithelial necrosis, sloughing of epithelial cells were observed in ileum sections. The work concludes that modified cocoyam starches could be useful in targeted mucoadhesive drug delivery.
Formulation optimization of floating microbeads containingmodified Chinese yam starch using factorial design.
(IPEC-Americas Inc., 2012-03) Okunlola, A.; Odeku, O. A; Patel, R. P.
Controlled release floating metformin hydrochloride microbeads were prepared and optimized using a blend of varying concentrations of freeze-dried pregelatinized Chinese yam starch (Dioscorea oppositifolia L) and sodium alginate. Floating microbeads were prepared by the ionotropic gelation method using 10% w/v calcium chloride as the cross-linking agent and sodium bicarbonate as the gas releasing agent. A full 32 factorial design was used to investigate the influence of two variables: concentrations of starch (X1) and sodium bicarbonate (X2) on the swelling, floating lag time and amount of drug released after 1 hour (Q1) and 10 hours (Q10). Potential variables such as the concentrations of drug and total polymer were kept constant. The results showed that the properties of the floating microbeads were significantly (p<0.01) affected by the concentration of the modified Chinese yam starch. Buoyancy and drug release appeared to be facilitated by increased concentrations of both starch and sodium bicarbonate in the formulation. The results also show that an optimized formulation of metformin hydrochloride could be obtained with the potential for gastroretentive controlled drug delivery using a blend of freeze-dried pregelatinized Chinese yam starch and sodium alginate.
Formulation and in vitro evaluation of natural gum-based microbeads for delivery of ibuprofen
(Pharmacotherapy group, faculty of pharmacy, university of Benin, Benin City, 2013) Odeku, O. A; Okunlola, A.; Lamprecht, A.
Purpose: To investigate the effectiveness of three natural gums, namely albizia, cissus and khaya gums, as excipients for the formulation of ibuprofen microbeads. Methods: Ibuprofen microbeads were prepared by the ionotropic gelation method using the natural gums and their blends with sodium alginate at various concentrations using different chelating agents (calcium chloride, zinc chloride, calcium acetate and zinc acetate) at different concentrations. Microbeads were assessed for their morphology using SEM, swelling characteristics, drug entrapment efficiencies, release properties and drug release kinetics. Results: The natural gums alone could not form stable microbeads in the different chelating agents. Stable small spherical discrete microbeads with particle size of 1.35 ± 0.11 to 1.78 ± 0.11 mm, were obtained using the blends of natural gum: alginate at total polymer concentration of 2% w/v using 10% w/v calcium chloride solution at a stirring speed of 300 rpm. The encapsulation efficiencies of the microbeads ranged from 35.3 to 79.8 % and dissolution times, t15 and t80 increased with increase in the concentration of the natural gums present in the blends. Controlled release was obtained for over 4 h and the release was found to be by a combination of diffusion and erosion mechanisms from spherical formulations. Conclusion: The three natural gums would be useful in the formulation of ibuprofen microbeads and the type and concentration of natural gum in the polymer blend can be used to modulate the release properties of the microbeads.
Potentials of natural polymers as nanomaterials for pharmaceutical drugs delivery
(2013) Bablola, O. C.; Okunlola, A.; Odeku, O. A.
During the last decades, pharmaceutical technology has taken advantage of the advent of nanotechnology for its application in four broad areas of the pharmaceutical industry: drug delivery, diagnostic products, biomarker discovery and product packaging. Of all the potential pharmaceutical applications of nanotechnology, drug delivery is currently the most developed and seems to be the most promising for the long-term. Of great advantage is the concept and ability to manipulate molecules and supramolecular structures to produce drug delivery devices with great potential for improving the efficacy of drug delivery systems. Polymeric nanoparticles are colloidal carriers which usually consist of synthetic, semi-synthetic or natural polymers, and depending on the materials used and their manufacturing methods, nanoparticles can adopt diverse shapes and sizes with distinct properties. Natural polymers such as gelatin, albumin, alginate and chitosan have great potentials because of their inherent properties such as biocompatibility, non-immunogenicity, non-toxicity and biodegradability. In addition, they can be subjected to physical and chemical modifications to alter their physic-chemical properties resulting in a wide range of functional properties that may permit their application as polymers for the formulation of nanoparticles. Moreover, they have been found to issues and relatively inexpensive when compared to the synthetic polymers. This paper is a review of some natural polymers that have shown promise as biodegradable polymers for the formulation of nanoparticulate drug delivery system.
Characterization and evaluation of acid-modified starch of Dioscorea oppositifolia (Chinese yam) as a binder in chloroquine phosphate tablets
(2013) Okunlola, A.; Akingbala, O.
Chinese yam (Dioscorea oppositifolia) starch modified by acid hydrolysis was characterized and compared with native starch as a binder in chloroquine phosphate tablet formulations. The physicochemical and compressional properties (using density measurements and the Heckel and Kawakita equations) of modified Chinese yam starch were determined, and its quantitative effects as a binder on the mechanical and release properties of chloroquine phosphate were analyzed using a 23 full factorial design. The nature (X1), concentration of starch (X2) and packing fraction (X3) were taken as independent variables and the crushing strength–friability ratio (CSFR), disintegration time (DT) and dissolution time (t80) as dependent variables. Acid-modified Chinese yam starch showed a marked reduction (p<0.05) in amylose content and viscosity but increased swelling and water-binding properties. The modified starch had a faster onset and greater amount of plastic flow. Changing the binder from native to acid-modified form led to significant increases (p<0.05) in CSFR and DT but a decrease in t80. An increase in binder concentration and packing fraction gave similar results for CSFR and DT only. These results suggest that acid-modified Chinese yam starches may be useful as tablet binders when high bond strength and fast dissolution are required.
Microbead design for sustained drug release using four natural gums
(Elsevier, 2013) Odeku, O. A.; Okunlola, A.; Lamprecht, A
Four natural gums, namely albizia, cissus, irvingia and khaya gums have been characterized and evaluated as polymers for the formulation of microbeads for controlled delivery of diclofenac sodium. The natural gums were characterized for their material properties using standard methods. Diclofenac microbeads were prepared by ionotropic gelation using gel blends of the natural gums and sodium alginate at different ratios and zinc chloride solution (10%w/v) as the crosslinking agent. The microbeads were assessed using SEM, swelling characteristics, drug entrapment efficiencies and release properties. Data obtained from in vitro dissolution studies were fitted to various kinetic equations to determine the kinetics and mechanisms of drug release, and the similarity factor, f2, was used to compare the different formulations. The results showed that the natural gum polymers varied considerably in their material properties. Spherical and discrete microbeads with particle size of 1.48–2.41μm were obtained with entrapment efficienciesof 44.0–71.3%w/w. Drug release was found to depend on the type and concentration of polymer gumused with formulations containing gum:alginate ratio of 3:1 showing the highest dissolution times. Con-trolled release of diclofenac was obtained over for 5 h. Drug release from the beads containing the polymer blends of the four gums and sodium alginate fitted the Korsmeyer–Peppas model which appeared to be dependent on the nature of natural gum in the polymer blend while the beads containing alginate alone fitted the Hopfenberg model. Beads containing albizia and cissus had comparable release profiles to thosecontaining khaya (f2> 50). The results suggest that the natural gums could be potentially useful for the ormulation controlled release microbeads.
Entandophragma angolense (WELW) CDC GUM AS A NOVEL BINDER AND MUCOADHESIVE COMPONENT IN ORAL TABLETS
(2013-05) ADETUNJI, O. A.
Mucoadhesive drug delivery systems are designed to prolong drug retention, thus offering advantages over conventional dosages through reduced dosage regimen and improved patient compliance. Natural polymers have gained importance over synthetic materials as excipients in such systems because they are less expensive, biocompatible and biodegradable. Entandophragma angolense gum (ENTA) is used in traditional medicine as a febrifuge, but its excipient properties have not been exploited. This study was carried out to evaluate ENTA as a novel polymer-binder and mucoadhesive component in oral tablets. Entandophragma angolense gum, obtained as dried exudates from the incised trunk of the tree, was characterised using material properties, rheological studies, Fourier-Transform Infrared spectrometer and X-ray diffractometer. Tablets were prepared by Wet Granulation (WG) and Direct Compression (DC) techniques using 2.5 - 10.0 %w/w polymer as binder and 60.0 - 90.0 %w/w polymer as matrix system for controlled release tablets containing ENTA (or official gelatin or hydroxypropylcellulose) with chlorpheniramine maleate (CPM) and ibuprofen as model drugs. Compressional characteristics of the tablets were determined using density measurements, and the Heckel and Kawakita plots. Mechanical and release properties of the tablet formulations were determined by standard methods. Mucoadhesive time (MT) of the tablets were determined ex-vivo in phosphate buffer (pH 7.4) and 0.1M hydrochloric acid (HCl, pH 1.2) using the rotating cylinder method containing excised pig ileum. Data were analysed using descriptive statistics, ANOVA and regression at p = 0.05. The ENTA consisted of irregularly shaped particles with a swelling index of 51.3 %. Rheological studies showed that the final viscosity of 5.0 %w/v ENTA was 258.17 poise. The gum contained hydroxyl groups and was amorphous with some degree of crystallinity. When used as a binder, the ranking of yield pressure was hydroxypropylcellulose > ENTA > gelatin, while the ranking was the reverse for plasticity index. Tablets formulated by WG had higher Tensile Strength (TS) and lower Brittle Fracture Index (BFI) and friability. The ranking of TS was hydroxypropylcellulose > ENTA > gelatin, while those of BFI and friability were the reverse. There was strong correlation(r > 0.98) between binder concentration and dissolution times. When used as polymer for controlled release matrices, the TS increased with binder concentration with tablets prepared by DC technique giving better release profiles than WG technique. The ranking of the disintegration and dissolution times was hydroxypropylcellulose > ENTA > gelatin (p < 0.05). The MT increased with polymer concentration with ibuprofen matrices showing significantly higher MT values than CPM matrices. Generally, the tablets adhered longer in 0.1M HCl, with a ranking of hydroxypropylcellulose (313.00 ± 0.18mins) > ENTA (300.01 ± 0.06mins) > gelatin (207.03 ± 0.11 mins). The polymer matrices provided zero-order drug release for over 14 hours. Entandophragma angolense gum could serve as an alternative binder to official polymers when high mechanical strength is desired. The gum could also serve as a mucoadhesive component in the controlled release of compressed tablets and matrices.
The pharmaceutical quality of brands of metformin tablets in Ogun-State, Nigeria
(2014-01) Ajala, T. O.; Adebona, A. C.; Bamiro, O. A.
The pharmaceutical quality of randomly selected brands of metformin tablets used (prescribed or dispensed) by Community Pharmacists and Doctors in Ogun state, southwestern Nigeria, were evaluated. Eight brands were randomly procured from community pharmacies after administering a pre-tested semi-structured questionnaire to 100 Pharmacists and 15 Physicians across different local government areas in Ogun state, South Western part of Nigeria. The physicochemical properties of the different brands were analysed using the Pharmacopoeia standard. The results showed that Pharmacists’ choice of stocking was based mainly on clients’ demand and quality, while doctors prescribe what is made available by the hospital pharmacy. Out of the eight brands assessed, seven are pharmaceutically equivalent and can be substituted for one another. However, there were quality variations from brand to brand. The ranking of crushing strength for the metformin brands was H>>>G>E>F>D>B>C>A, while the trend for friability was D>>>E>C>H>A>G>F>B. The trend of disintegration time among the brands was D>G>C>E>A>F>B>H and ranking of CSFR/DT was H>>B>F>G>A>E>C>>D. Two brands (D and E) failed the friability test while brand D had significantly lower balance of mechanical and release properties as determined by CSFR/DT. There is therefore a continuous need for random assessment of the quality of metformin brands by regulatory bodies to ensure compliance to specifications. `
Disintegrant properties of native and modified polymers in metronidazole tablet formulations
(2014-09) Ayorinde, J. O.; Odeniyi, M. A.
Natural polymers may be modified in order to improve desired properties in tablet formulations. Granule incorporation techniques have different effects on the disintegrant properties of tablets. Disintegrant properties of two new plant polymers, extracted from Pigeon pea (Cajanus cajan) and Khaya senegalensis tree, were investigated in metronidazole tablet formulations. Native and microwave irradiated forms of the starch and gum were incorporated into the tablet formulations using a 3-factor general full factorial design. Type of disintegrants (X1) was at two levels (Starch or Gum), effect of modification (X2) was also investigated at two levels (Native or Irradiated), while the mode of incorporation (X3) of the disintegrants was at three levels (Intragranular (IG), Extragranular (EG) or Intra-extragranular (IG/EG). Sodium starch glycolate was the standard. Tablets were evaluated for disintegration, dissolution and physical qualities using British Pharmacopoeia methods. The native and modified gum showed higher hydration capacity than the starches. The rank order of the disintegrant properties of the polymers was MG (modified gum)>NG (native gum)>MS (modified starch)>NS (native starch) (p<0.05). The crushing strength for tablets from both native and modified polymers was similar but differs with the mode of incorporation. In starch, the rank orders were IG/EG > IG > EG; and EG > IG/EG > IG for the gums. However, IG/EG incorporation of native and modified starches and gums gave a longer t80 (time taken for 80% of the drug to dissolve) than both IG and EG (p<0.05). The effect of the variables on the disintegrant properties of the polymers was in the order: X3 > X1 > X2 and the effect on t80 was X1 > X3 > X2. The gums and starches were better disintegrants than sodium starch glycolate, with the gums exhibiting better properties than the starches. Microwave irradiation had no significant effect on the disintegrant properties of both polymers but increased the crushing strength of the tablets. Intragranular incorporation proved to be the best method for optimum disintegrant property.
Design of cissus–alginate microbeads revealing mucoprotection properties in anti-inflammatory therapy
(Elsevier B.V., 2015) Okunlola, A.; Odeku, O. A.; Lamprech, A.; Oyagbemi, A. A.; Oridupa, O. A.; Aina, O. O.
Cissus gum has been employed as polymer with sodium alginate in the formulation of diclofenac microbeads and the in vivo mucoprotective properties of the polymer in anti-inflammatory therapy assessed in rats with carrageenan-induced paw edema in comparison to diclofenac powder and commercial diclofenac tablet. A full 23 factorial experimental design has been used to investigate the influence of concentration of cissus gum (X1); concentration of calcium acetate (X2) and stirring speed (X3) on properties of the microbeads. Optimized small discrete microbeads with size of 1.22 ± 0.10 mm, entrapment efficiency of 84.6% and t80 of 15.2 ± 3.5 h were obtained at ratio of cissus gum:alginate (1:1), low concentration of calcium acetate (5% w/v) and high stirring speed (400 rpm). In vivo studies showed that the ranking of percent inhibition of inflammation after 3 h was diclofenac powder > commercial tablet = cissus > alginate. Histological damage score and parietal cell density were lower while crypt depthand mucosal width were significantly higher (p < 0.05) in the groups administered with the diclofenac microbeads than those administered with diclofenac powder and commercial tablet, suggesting the mucoprotective property of the gum. Thus, cissus gum could be suitable as polymer in the formulation of non-steroidal anti-inflammatory drugs ensuring sustained release while reducing gastric side effects.