Entandophragma angolense Gum as a Novel Binder and Mucoadhesive Component in Oral Tablets

The present work reports on the mucoadhesive and mechanical properties of the water-soluble gum obtained from Entandophragma angolense when incorporated in oral tablets. Flat-faced chlorpheniramine maleate tablets containing the gum were formulated. The potential for chemical interaction between the gum and drug was evaluated by UV spectroscopy. The mucoadhesive, mechanical and release properties of the tablets were evaluated. The rates of water uptake and erosion were determined for the tablets. The detachment time for the tablets increased from 78.71 ± 0.43 to 84.28 ± 0.75 min, and from 33.57 ± 0.48 to 79.27 ± 4.7 min as the amount of gum per tablet was increased from 2.5 to 10.0% w/w, respectively. The drug release time for all tablets increased with binder concentration. UV spectroscopy suggested the absence of chemical interactions. The novel natural gum compared favourably with established mucoadhesive polymers namely hydroxypropylcellulose and gelatin. The mucoadhesive, mechanical and release properties were a function of polymer concentration.Key words: Entandophragma angolense, chlorpheniramine maleate tablets, mucoadhesion, mechanical propertie

Packing and cohesive properties of some locally extracted starches

Purpose: The packing and cohesive properties of locally developed cassava, potato and yam starches have been characterised using the maximum volume reduction due to packing as expressed by the Kawakita constant a, and the angle of internal flow, θ, respectively. Methodology: The starches were characterized for their particle size, shape and particle size distribution using optical microscopy. Tapping experiments were used to quantify the packing and cohesive properties of the starches. The volume reduction ability was estimated using the Kawakita equation. Results: The shape factor of the starches provided a proportionality constant between the particle size and surface area. The rank order of the particle size and shape factor of the starches was yam >potato >cassava. The ranking of maximum volume reduction, a, for the starches was potato > cassava > yam while the ranking for the angle of internal flow,θ, an index of cohesiveness, was cassava > potato > yam. The values of these parameters depended on the physical properties of the starches. Conclusion: The results obtained indicate that the physical properties of the particles affect the packing and cohesive properties of the starches, and are important in predicting the behaviour of the starches during handling and use in pharmaceutical preparations. These properties need to be closely controlled in pre-formulation studies

Packing and cohesive properties of some locally extracted starches

Purpose: The packing and cohesive properties of locally developed cassava, potato and yam starches have been characterised using the maximum volume reduction due to packing as expressed by the Kawakita constant a, and the angle of internal flow, θ, respectively. Methodology: The starches were characterized for their particle size, shape and particle size distribution using optical microscopy. Tapping experiments were used to quantify the packing and cohesive properties of the starches. The volume reduction ability was estimated using the Kawakita equation. Results: The shape factor of the starches provided a proportionality constant between the particle size and surface area. The rank order of the particle size and shape factor of the starches was yam >potato >cassava. The ranking of maximum volume reduction, a, for the starches was potato > cassava > yam while the ranking for the angle of internal flow,θ, an index of cohesiveness, was cassava > potato > yam. The values of these parameters depended on the physical properties of the starches. Conclusion: The results obtained indicate that the physical properties of the particles affect the packing and cohesive properties of the starches, and are important in predicting the behaviour of the starches during handling and use in pharmaceutical preparations. These properties need to be closely controlled in pre-formulation studies

Effects of plantain and corn starches on the mechanical and disintegration properties of paracetamol tablets

The effects of plantain starch obtained from the unripe fruit of the plantMusa paradisiaca L. (Musaceae) on the mechanical and disintegration properties of paracetamol tablets have been investigated in comparison with the effects of corn starch BP using a 23 factorial experimental design. The individual and combined effects of nature of starch binder (N), concentration of starch binder (C), and the relative density of tablet (RD) on the tensile strength (TS), brittle fracture index (BFI), and disintegration time (DT) of the tablets were investigated. The ranking of the individual effects on TS was RD>C≫N, on BFI was C≫RD>N and on DT was N>C>RD. The ranking for the interaction effects on TS and DT was N-C≫N-RD>C-RD, while that on BFI was N-C≫C-RD>N-RD. Changing nature of starch from a “low” (plantain starch) to a “high” (corn starch) level, increasing the concentration of starch binding agent from 2.5% to 10.0% wt/wt, and increasing relative density of the tablet from 0.80 to 0.90, led to increase in the values of TS and DT, but a decrease in BFI. Thus, tablets containing plantain starch had lower tensile strength and disintegration time values than those containing corn starch, but showed better ability to reduce the lamination and capping tendency in paracetamol tablet formulation. The interaction between N and C was significantly (P<.001) higher than those between N and RD and between C and RD. There is therefore the need to carefully choose the nature (N) and concentration (C) of starch used as binding agent in tablet formulations to obtain tablets of desired bond strength and disintegration properties. Furthermore, plantain starch could be useful as an alternative binding agent to cornstarch, especially where faster disintegration is required and the problems of lamination and capping are of particular concern

PROPERTIES OF STARCHES OBTAINED FROM COLOCASIA ESSCULENTA AND ARTOCARPUS COMMUNIS

Artocarpus communis (breadfruit) and Colocasia esculenta (cocoyam) starches compared favourably with Zea mays (corn) starch and complied individually with the official requirements as specified in the British Pharmacopoeia and Handbook of Pharmaceutical excipients. Key Words: Colocasia esculenta, Artocarpus communis, Araceae, Moraceaem, starch elemental analysis. Nig. J. Nat. Prod. And Med. Vol.2 1998: 29-3

Preliminary investigation on industrial properties of the Olode-Falansa pegmatite, Southwestern Nigeria

In Olode-Falansa area, which is part of the southwestern basement complex of Nigeria near Ibadan, the major rock types are granite gneiss, quartzite, medium-grained granite and pegmatite. In particular, the pegmatites which occur as low-lying bodies, with a mineralogy dominated by pinkish-white microcline perthite, quartz, muscovite and plagioclase plus accessory constituents of garnet, beryl and tourmaline have been investigated for their distribution, physical, chemical and mineralogical characteristics in order to evaluate their industrial qualities. Chemical analysis shows variations in the major elements contents of the main minerals. In particular, quartz samples have 94.02 to 97.30% SiO2; 0.86 to 2.60% Al2O3; 0.05 to 1.02% K2O; and 0.13 to 1.29% Fe2O3, while the feldspar samples are 61.37 to 67.83% SiO2; 16.85 to 18.40% Al2O3; 11.35 to 14.32% K2O and 0.04 to 0.11% Fe2O3 respectively. The total alkalis (Na2O+K2O) indicate K-feldspar composition. The specific gravity for quartz ranges from 2.60 – 2.63, while that of feldspar is from 2.55 –2.58. Water absorption capacity is higher for quartz (25.10 – 27.10%) than feldspar (4.61 – 5.80%). Compressive strength of selected pegmatite minerals indicates values from 133.24 to 223.84MN/m2. This investigation shows that the pegmatites have good potential for industrial uses. They can be used directly as raw materials or after beneficiation. In particular, the quartz and feldspars can find application in the refractory, glass, ceramic and abrasive industries. They can also be found useful in minor construction works especially in homes and offices. Muscovite can be used as thermal and electrical insulators, while the beryl can be useful as ornaments. The associated rocks such as gneisses, quartzites and granites can be useful in interior and exterior decorations as well as in tiles manufacturing. KEY WORDS: Olode Pegmatite; K-feldspar; Quartz; Raw Materials Global Journal of Geological Sciences Vol.2(2) 2004: 255-26

Effect of humidity on the disintegrant property of α-cellulose, Part II: A technical note

The summary is that the high humidity impaired the disintegrant property of α-cellulose in all 3 tablets tested. Tablets of aspirin, which is the more hygroscopic drug, were also more sensitive to the humidity effect, while tablets of chloroquine phosphate, which is a water-soluble drug, were the least sensitive to the humidity effect. The results permit the conclusion that moisture uptake with subsequent gelling of the α-cellulose is the mechanism of impairment of its disintegrant property. The tablets would not normally be stored under an RH as high as 100%, nevertheless, the results of the accelerated stability study have underscored the need to protect tablets containing α-cellulose as disintegrant from moisture