FACULTY OF PHARMACY
Permanent URI for this communityhttps://repository.ui.edu.ng/handle/123456789/271
Browse
Item 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.Item Management of congestive heart failure (CHF): a case report on digoxin(1999) Omole, M. K.A case report on the management of congestive heart failure is presented with emphasis on the use of DIGOXIN.Item performance of an acid-cassava starch medium in the propagation of fungi(1999) Adeleke, O. E.; Odelola, H. A.; Onasanya, Y.Item 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.Item 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.Item Compressional characteristics and tableting properties of starches obtained from four dioscorea species(2009) Okunlola, A; Odeku, O. AThe 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.Item 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.Item Formulation factors affecting the binding properties of chinese yam (dioscorea oppositifolia) and corn starches(Elsevier, 2009) Okunlola, A.; Odeku, O. AObjective; 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.Item 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 hydrochlorideItem 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.Item In-vitro antimicrobial activities of methanol extracts of(2010-01) Adeniyi, C. B. A.; Odumosu, B. T.; Ayelaagbe, O. O.; Kolude, B.The antimicrobial activities of two Nigerian medicinal plant commonly used as chewing sticks Zanthoxylum xanthoxyloides and Pseudocedrela kotschyi antimicrobial activities were investigated against 7clinical strains of Streptococcus mutans, Staphylococcus aureus ATCC 29213, Candida albicans, Candida tropicalis and Candida krusei ATCC 6825. The antibacterial and antifungal activities of the extracts were determined using the agar well diffusion and surface plate method respectively. Zanthoxylum xanthoxyloides, was active against all the isolates especially on the bacteria with a MIC and MBC of 12.5mg/mL and 25mg/mL respectively. Pseudocedrela kotschyi showed no activity on all the tested isolates except on C. krusei ATCC 6825 with a MIC of 6.25mg/mL. . Streptococcus mutans, S. aureus ATCC 29213 and C. albicans were completely killed within the time period of4hrsbyZ. xanthoxyloides extracts in time kill study. A good correlation was foundbetween the killing curves and the MIC of Z. xanthoxyloides against the tested isolates. Phytochemical screening revealed the presence of alkaloids, tannins, flavonoids, saponins and traces of terpenoids. Ability of Z. xanthoxyloides crude extracts to inhibit the growth of the bacteria and fungi used in this study is an indication that the plant can be used as a source foranti microbial agent in the development and formulation of toothpaste, thus justifying the use of the plant in locally as chewing sticks..Item A survey of antimalarial drug use practices among urban dwellers in Abeokuta, Nigeria(2010-01) Omole, M. K.; Onademuren, O. T.Drug-use pattern of anti-malarial has been associated with development of resistant strain and therapeutic failure. This descriptive cross-sectional study was carried out to assess anti-malarial drug-use practices among dwellers of Adigbe communities within Abeokuta environment. The study documented the knowledge, the attitude and behaviour of three hundred and fifty (350) respondents in terms of drug preference, attitude to drug use and the effects of non-compliance to antimalarial drug. Structured questionnaires were used for data collection, as total of 370 questionnaires were distributed and 350 questionnaires were retrieved for analysis. One hundred and twenty five (125) (35.71) of the respondents frequently experienced malaria attack and practiced self-medication. One hundred and fifteen (115) (32.86%) of the respondents treated their malaria episode with Sulphadoxine-Pyrimethamine (SP) combination while 90 (25.71%) of the respondents frequently purchased Artesunate as monotherapy for malaria treatment due to cost-implication of the newer and available Artemisinin combination therapy (ACT’s). The finding reveals that 43 (12.29%) of the respondents only purchased Artemisinin-Combination Therapy (ACTs). One hundred and eight can 118 (33.71%) of the respondents practiced self-medication with anti-malarial drug. The results revealed therapeutic failure to conventional use of Sulphadoxine-Pyrimethamine (SP) by the respondents as One hundred and thirty nine (139) (33.71%) of the respondents experienced no cure and have to repeat the treatment with anti-malarias. If drug-use pattern of anti-malarials is not monitored, there is possibility of early emergence of resistance to the highly effective anti-malarial drugs presently in use.Item Patient medication knowledge governing adherence to asthma pharmacotherapy: A survey in rural Lagos, Nigeria(2010-05) Omole, M.K.; Ilesanmi, N. A.Asthma is a chronic disease and often requires complex management. This study was undertaken in four pharmacies–V-Ninat Pharmacy, Videc Chemists, Tomabel Pharmacy and Josbet Chemists, all in Isolo, Lagos, to determine the level of adherence to the anti-asthmatic drugs by asthmatic patients who participated in the study. Data was collected using structured questionnaires administered to patients coming into the pharmacies. The questionnaire was administered during a one-on-one interview. Times of recruitment were varied in an attempt to avoid any bias or restriction of the sample in relation to gender, age, or employment status such as trading and teaching. There were 73 participants in the study. The participation rate was 67 (92%) of those individuals eligible. The mean age of participants was 57(± 17.7) years. 30 (45.2%) of respondents were males and 37 (54.8%) were females. The mean number of occasion of exercise per week was 28.26. Twenty six (26) (39.0%) of patients used “preventer” medication, that is medication that prevents asthmatic attack on those who frequently suffer from asthma, and 5 (7%) never used it. Participants offered a number of reasons explaining their non-adherence, the most common 24 (58.5%) were those who forgot to take “preventer” medication. Nine (9) (21.9%) were too busy, 5 (12.2%) were concerned about side effects and 3 (7.3%) did not believe it was effective. Other responses were offered only by individual participants and were not endorsed by the participant sample. Older patients adhered to their medication regimen more closely than younger patients. Fifty (50) (68%) patients used “preventer” medication and 17 (26%) patients used “reliever” that is, agent that relieves asthmatic attack on those who frequently suffer from asthma. Based on these findings and the result of hypothesis testing (p < 0.05), the study established poor medication knowledge, suboptimal device technique, and disturbing levels of patients adherence with management recommendations. Asthma education strategies need to be modified to engage patients with low asthma knowledge to achieve improved patient outcome. Further, strategies should be employed to motivate patients to use “preventer” medications during the times they feel well.Item 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.Item In-Vitro Susceptibility of Mycobacterium Tuberculosis to Extracts of Uvaria Afzelli Scott Elliot and Tetracera Alnifolia Willd(2011-01) Lawal, T. O.; Adeniyi, B. A.; Wan, B.; Franzblau, S. G.; Mahady, G. B.Tuberculosis is a global burden with one –third of the world’s population infected with the pathogen Mycobacterium tuberculosis and an annual 2 million deaths from the disease. This high incidence of infection and the increased rate of resistant strains of the organism (MDR- and XDR- TB) have called for an urgent need to develop new anti-tuberculosis drugs from plants. The crude extract of Uvaria afzelli Scott Elliot (Annonaceae) root bark, and leaves and root bark of Tetracera alnifolia Willd. (Dilleniaceae) were investigated for anti-Mycobacterium tuberculosis activity using the MABA assay method. Anti- Mtb activity was determined against Mtb H37RvATCC 27294 at concentrations of 100- 0.390μg/mL. The hexane and chloroform extracts of the root bark of Tetracera alnifolia and the chloroform extract of Uvaria afzelli had anti- Mtb activity with MIC <100 μg/mL. Phytochemical screening for secondary metabolites revealed the presence of tannins, triterpenoid saponins, cardiac glycoside and alkaloids. The anti- Mtb activity demonstrated by the crude extracts is attributed to the presence of tannins and other secondary metabolites which are known to have strong antimicrobial activity. The results therefore support the local use of Uvaria afzelli and Tetracera alnifolia in the treatment of cough associated with tuberculosis and other microbial infections of the respiratory tract and suggest that these plants may be of therapeutic importance in the treatment of tuberculosis.Item 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 formulationItem Antimicrobial and pharmaceutical properties of the seed oil of leucaena leucocephala (Lam.) de wit (Leguminosae)(2011-01) Aderibigbe, S. A.; Adetunji, O. A.; Odeniyi, M. A.The seed oil of Leuconia leucocephala was investigated for its antimicrobial activity and the pharmaceutical properties of its lotion formulation determined. The oil was extracted from the pulverised dried seeds of the Leuconia leucocephala plant by cold maceration in n-hexane. The oil was tested against four bacteria (Staphylococcus aureus, Esherichia coli, Bacillus subtilis and Pseudomonas aeruginosa) and four fungi (Aspergilus niger, Rhizopus stolon, Penicillum notatum and Candida albicans) isolates. Gentamycin and tioconazole were the reference drugs respectively. The oil was later formulated as a lotion and the pharmaceutical properties of the formulation determined.The oil was found to have a concentration-dependent activity against both Gram-positive and Gram-negative bacteria, while showing no activity against the fungi tested. The lotion formulation of the oil containing oleic acid had good pharmaceutical properties and was stable over the test period. Leucaena leucocephala seed oil extract had a concentration-dependent activity against both Gram-positive and Gram-negative bacteria and the lotion formulation had good pharmaceutical properties.Item Antifungal capacity of lactic acid bacteria isolated from salad vegetables(2011-05) Adeniyi, B.; Damsa, I.This study explores the use of lactic acid bacteria from fresh salad vegetables to inhibit fungal growth. The antifungal assay was done using the agar well diffusion method as reported by Schillinger and Lucke (1989). The largest zone of inhibition (25mm) was recorded by the antagonistic activity of the isolate identified to Lactobacillus plantarum against Candida albicans ATCC 90029. No activity was recorded against Candida parapsilosis ATCC 22019, C. valida UCH 1508, C. pseudotropicalis UCH1408, C. tropicalis UCH 1308 and Trichophyton interdigitalis UCH1708. The cell free supernatant (CFS) of the isolate described to be Lactobacillus brevis was exceptional as it was the only CFS that inhibited the growth of Epidermophyton floccosum UCH 1908. The results show that LAB isolated from salad vegetables can inhibit some fungi pathogens by developing zones around agar well that contain LAB metabolites and can probably be a feasible option for the chemotherapy of fungal infections given the drug resistance exhibited to antifungal agents currently in use.Item 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.Item 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.
- «
- 1 (current)
- 2
- 3
- »