Evaluation of modified breadfruit (Artocarpus altilis) starches as immediate and sustained release polymers in bilayer tablets of ibuprofen

Background: Ibuprofen, administered as conventional oral tablets every 4 -6 hours, has some gastrointestinal side effects. Its formulation as sustained and immediate release layers in a compact bilayer tablet avoids the challenge of multiple daily dosing, reducing untoward side effects.Objectives: The objective of the study is to formulate bilayer tablets of ibuprofen using breadfruit (Artocarpus altilis) starches modified by carboxymethylation and acid hydrolysis for immediate and sustained release, respectively, in comparison to sodium starch glycolate (SSG) and hydroxypropyl methyl cellulose (HPMC).Methods: The starches were characterized using Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, viscosity, swelling power, densities and flow properties. Bilayer tablets of ibuprofen were prepared using carboxymethylated Breadfruit starch (5.0 and 7.5%w/w) and acid-hydrolyzed starch (17.0%w/w) and evaluated using crushing strength, friability, disintegration and dissolution times (t80).Results: FTIR and XRD spectra confirmed modification of starches. Carboxymethylation produced starches of higher swelling and flow properties while acid-modification produced higher compressibility. Bilayer tablets containing modified starches had higher crushing strength than the standards. Disintegration time of the fast release layers was 1.00 - 10.37 min. An initial burst release was followed by sustained release (t80 = 4.5 - 9.0 h) with tablets containing the acid modified starch having longer dissolution than HPMC. Drug release fitted the First order, Hixson-Crowell and Hopfenberg kinetic models.Conclusion: Carboxymethylated and acid-modified breadfruit starches were found suitable as cheaper excipients in bilayer tablet formulations for immediate and sustained release of drugs respectively, particularly where high mechanical strength is required.Keywords: Acid-modification, bilayer tablets, breadfruit starch, carboxymethylation, ibuprofe

Compaction and Tableting Behavior of a Novel Co-Processed Excipient in the Formulation of Metoprolol Succinate Tablets

Background: Pregelatinized starches exhibit good swelling and flow properties, imparting fast disintegration time but low mechanical strength in tablets. On the other hand, acacia gum acts as a binder in tablets by imparting high mechanical strength but prolonged disintegration time. Development of a co-processed excipient involving combination of the two excipients at sub-particle level will improve the functionality of the final product.Objective: To develop a direct compressible co-processed excipient with pregelatinized cocoyam starch and acacia gum and to evaluate its compaction behavior and tableting properties in metoprolol succinate tablets.Material and Methods: Batches of the co-processed excipient were prepared by co-fusion using different ratios (97.5:2.5; 95:5; 92.5:7.5; 90:10; 85:15; 80:20) of pregelatinized cocoyam starch and acacia gum. Flow and compaction properties and Fourier transform Infrared (FT-IR) analysis were carried out on native and pregelatinized starches and on the co-processed excipients. Metoprolol succinate tablets were formulated by direct compression using selected batches of co-processed excipients, pregelatinized cocoyam starch and acacia gum and then evaluated for mechanical strength and drug release.Results: Pregelatinization produced starch with larger granules (138.75±59.21μm), improved swelling (2.03±0.00) and flow (flow rate 0.52±0.03g/s). The FTIR analysis of the co-processed excipients confirmed absence of chemical interaction. Flow properties, compressibility (Kawakita value, a = 0.190 – 0.223) and rate of packing (Consolidation rate, K = 0.1221 – 0.2551) of the co-processed excipients were enhanced. Metoprolol succinate tablets containing the co-processed excipients had higher mechanical strength (Crushing strength 106.03±15.80 MNm-2) than those containing starch alone but faster drug release (disintegration time 1.80 ±0.20 -5.75±0.25; dissolution time; t80 30-50 min) than those containing acacia gum. Cocoyam starch: acacia gum ratio 97.5:2.5 gave the optimum formulation with high crushing strength (106.03 ± 15.8MNm-2) and fast release (t80 = 30 min).Conclusion: Co-processed excipients of pregelatinized cocoyam starch and acacia gum could serve as suitable alternatives to other directly-compressible excipients for the formulation of tablets. Keywords: Acacia gum, Cocoyam starch, Compaction properties, Co-processing, Metoprolo

Formulation Design and Optimization of Theophylline Microspheres Containing Akidi Beans (Vigna Unguiculate) Starch as Polymer Using Central Composite Design

The aim of the study was to use central composite design in formulating theophylline microspheres containing Akidi beans (Vigna unguiculata L Warp) starch as a controlled-release polymer. Theophylline microspheres containing pregelatinized Akidi beans starch, alginate and chitosan were prepared using ionic gelation. A 2 factor, 2 Level central composite design was used with starch:alginate ratio (X1) and polymer:drug ratio (X2) as variables, and size, entrapment efficiency and quantity of drug released in 12 h, Q12, as responses. Regression parameters and response surface plots were generated. The microspheres were spherical with size 1.68 00 ± 0.12 – 1.95 ± 0.03 mm. Optimized formulation containing 4:1 Akidi starch: alginate and 3:1 polymer: drug ratios, prepared according to levels determined by Minitab software using desirability function, showed significant increase in the responses in comparison to those containing alginate alone. Akidi beans starch demonstrated good potential as an alternative polymer for the controlled delivery of drugs. Key words: Akidi beans starch, central composite design, controlled release, desirability function, sodium alginate, theophylline microsphere

Farmers perception of problems in the cultivation of selected leaf vegetables in South Western Nigeria

The development of alternative strategies for sustainable pests’ management in vegetable production (using insecticides of plant origin) is particularly important in a country like Nigeria where synthetic insecticides are not readily available and farmer s are poorly equipped to handle them. This research was conducted to unravel farmers’ perception of insect pest activities as a constraint to vegetable production and to ascertain the most important pests and indigenous methods of control (using plant extracts). Baseline surveys were conducted using well structured questionnaire on farmers’ plots in farming communities of Akure North and South Local Government Areas of Ondo State. Results from the study affirmed, that all the farmers had the problem of pests on their farms. They have ranked Podagrica sjostedti, P. uniforma, Sylepta derogata, Dsydercus superstitiosus, and Zonocerous variegata as the most important insect pests of the selected leaf vegetables: Amaranthus hybridus, Celosia argentea, and Corchorus olitorius. The results further indicated that 76% of the farmers were aware of the use of indigenous methods of control (using different plant extracts) for the control of pests. The study showed that there was no significant association between education and the use of plant extracts. However, age, sex, and farming experience influenced the use of the plant extracts for insect pest control on the respondents’ farm

Evaluation of starches obtained from four Dioscorea species as binding agent in chloroquine phosphate tablet formulations

AbstractStarches 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

Influence of Pregelatinized Breadfruit Starch-Alginate Blend as a Sustained Release Polymer in Theophylline Microbeads Using Box Behnken Design

Background: Apart from the coating property of modified starches on drugs, these natural polymers also acts as release rate retardants.Objectives: To evaluate the potential of pregelatinized breadfruit (Artocarpus altilis) starch as a carrier in microbead formulations of theophylline using different blend combinations with sodium alginate and to determine the optimized formulation using Box-Behnken design.Method: Theophylline microbeads were prepared using the ionic gelation method. The 3 factor-3 level Box-Behnken design was employed for constructing polynomial models to optimize the microbeads, involving 3 independent variables (polymer type, X1, polymer: drug ratio, X2, and concentration of calcium chloride, X3) and 2 dependent variable (entrapment efficiency and quantity of drug released in 12 h, Q12).Results: Entrapment efficiency was 35 - 71 % while the values of Q12 was 38 - 88 %. The three variables, X1, X2 and X3, were positive for entrapment efficiency but negative for Q12, implying that increase from low to medium and then to high level resulted in an increase in entrapment but a decrease in Q12 (sustained release), both desirable effects. Factor X1 had the most significant influence on entrapment efficiency and Q12 (p = 0.002; p = 0.0001, respectively). The optimized formulation with starch:polymer 2:1, polymer:drug 3:1 and 7.5%w/v calcium chloride solution gave an entrapment efficiency 65% with Q12 of 38.75%.Conclusion: Pregelatinized breadfruit starch enhanced entrapment efficiency while retarding drug release, showing its potential as a polymer for sustained release in microbead formulations. Keywords: Box-Behnken design; Breadfruit starch; Ionic gelation, Microbeads, Pregelatinizatio

Generic versus innovator: Analysis of the pharmaceutical qualities of paracetamol and ibuprofen

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. Keywords: Generic, innovator brand, paracetamol, ibuprofen, physicochemical equivalence East Central African Journal of Pharmaceutical Sciences Vol. 12 (2009) 55-6

The Impact of Export Promotion Schemes on Agricultural Growth in Nigeria

This paper examines the impact of government export promotion schemes on the growth of agriculture in Nigeria. Employing an ARDL cointegration technique, impulse-response functions and variance decompositions, the results indicate a significant positive impact of the government export promotion schemes on agricultural output growth in the short- and long-run. The findings highlight the need to be selective in the choice of export promotion strategies in Nigeria. Most notably, government must not only provide more credit facilities to the sector but also ensure increased recurrent and capital expenditure in the agricultural sub-sector

Evaluation of Pharmaceutical and Microbial Qualities of Some Herbal Medicinal Products in South Western Nigeria

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. Keywords: Herbal medicinal products, microbial quality, pharmaceutical quality. > Tropical Journal of Pharmaceutical Research Vol. 6 (1) 2007: pp. 661-67