Application of the Gurnham Equation in Characterizing the Compressibility of Fonio and Sweet Potato Starches and their Paracetamol Tablet Formulations

Background: A number of empirical relationships have been proposed to describe the compaction of pharmaceutical materials, among them are the Heckel, Kawakita and Gurnham equations.Objective: To characterize the compressibility of fonio, sweet potato and corn starches and their paracetamol formulations using the Gurnham and Kawakita equations, and to determine the complementarity of these equations.Materials and Methods: Starches were extracted from fonio (Digitaria exilis) grains and sweet potato (Ipomea batatas) tubers and modified by acid hydrolysis for 96 h. Paracetamol formulations containing 2.5–10.0 %w/w starch binders were prepared by wet granulation. Packing and compaction properties of native and modified starches and their formulations were determined using tapping procedures. The data obtained was analyzed using the Gurnham and Kawakita equations.Results: The ranking for Gurnham compressibility, c, for the starches was sweet potato>corn>fonio, which was inversely related to the ranking for Kawakita maximum volume reduction, a and angle of internal flow, θ. There was no clear-cut pattern in the Gurnham compressibility of paracetamol formulation probably due to its multicomponent nature. There was correlation between c, a and θ for all the starches with the modified starches exhibiting higher compressibility than native starches. There appeared to be no correlation between c and Kawakita compressibility index, b.Conclusion: The Gurnham equation appeared useful in characterising compressibility in single component systems and could be used along with Kawakita functions, to gain a better understanding of the deformation of powdered materials under pressure.Keywords: Compressibility, Gurnham equation, Kawakita function, Fonio starch, sweet potato starc

The Pharmaceutical Properties, Microbial Quality, In-vivo Aphrodisiac Effect and Safety of Some Herbal Bitters Sold in Southwest Nigeria

Aphrodisiac drugs are used to enhance sexual activity and rectify erectile dysfunction especially among older men. In Nigeria, herbal medicinal products formulated as herbal drinks/bitters are prevalent and sold in various locations including motor parks, store and markets. Despite their wide use, the potency and safety of the herbal drinks have not been ascertained. Thus, pharmaceutical and aphrodisiac properties of five randomly selected herbal drinks with aphrodisiac claim have been evaluated. Pharmaceutical and microbial qualities were evaluated using standard procedures and the in vivo aphrodisiac activities were evaluated in male Wistar rats. The effects of chronic consumption of the bitters on the biochemical and tissue histology were assessed. The herbal bitters exhibited low viscosity (< 10 cP), high alcohol content (30 – 52 %), acidic pH (3.33 - 5.40), and low density (0.942-1.070 g/ml). The phytoconstituents include alkaloids, flavonoids, saponins, cardenolides, tannins and anthraquinone. Microbial contaminations were with the limits for oral preparations. The bitters exhibited significant (p < 0.001) aphrodisiac effect but had no significant effect on fertility and hematological parameters. Chronic consumption of the herbal drinks at 250mg/kg following was hepatotoxic while two brands were cardiotoxic and nephrotoxic. There is therefore the need to monitor and control the quality and use of herbal bitters/drinks sold in the Nigerian market to safeguard public healt

Characterization and evaluation of acid-modified starch of Dioscorea oppositifolia (Chinese yam) as a binder in chloroquine phosphate tablets

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

Influence of binder type and process parameters on the compression properties and microbial survival in diclofenac tablet formulations

The influence of binder type and process parameters on the compression properties and microbial survival in diclofenac tablet formulations were studied using a novel gum from Albizia zygia. Tablets were produced from diclofenac formulations containing corn starch, lactose and dicalcium phosphate. Formulations were analyzed using the Heckel and Kawakita plots. Determination of microbial viability in the formulations was done on the compressed tablets of both contaminated and uncontaminated tablets prepared from formulations. Direct compression imparted a higher plasticity on the materials than the wet granulation method. Tablets produced by wet granulation presented with a higher crushing strength than those produced by the direct compression method. Significantly higher microbial survival (pA influência do tipo de ligante e os parâmetros do processo de propriedades de compressão e sobrevivência microbiana em comprimidos de diclofenaco foram estudados utilizando uma nova goma de Albizia zygia. Os comprimidos foram produzidos a partir de formulações de diclofenaco contendo amido de milho, lactose e fosfato bicálcico. As formulações foram analisadas usando os gráficos de Heckel e Kawakita. A determinação da viabilidade microbiana nas formulações foi feita nos comprimidos contaminados e não contaminados preparados a partir de formulações. A compressão direta confere maior plasticidade dos materiais do que o método de granulação úmida. Comprimidos produzidos por granulação úmida apresentaram maior força de esmagamento do que aqueles produzidos pelo método de compressão direta. Observou-se sobrevivência significativamente maior (p<0,05) em formulações preparadas por compressão direta. A sobrevivência percentual dos esporos de Bacillus subtilis diminuiu com o aumento da concentração do agregante. O estudo mostrou que a goma de Albizia é capaz de conferir maior plasticidade aos materiais e apresentou maior redução da contaminação microbiana nas formulações. O método de compressão direta produziu comprimidos com viabilidade reduzida de contaminantes microbianos

Formulation of the extract of the stem bark of Alstonia boonei as tablet dosage form

Purpose: To formulate the extracts of the stem bark of Alstonia boonei , an important antimalarial herb, into tablet dosage form. Methods: Tablets were formulated using direct compression and wet granulation methods. The mechanical properties of the tablets were assessed using crushing strength and friability and the crushing strength:friability ratio (CSFR) while drug release properties were evaluated using disintegration and dissolution times. Results: There were statistically significant (p<0.01) differences in the CSFR values and drug release properties of A. boonei tablets prepared by both methods. The differences depended on the type and concentration of excipient and binder employed in the formulation. Conclusions: The method of preparation of the A. boonei tablets needs to be carefully selected to ensure the production of tablets with adequate bond strength to withstand the rigours of handling and at the same time release the active compound (s) for biological action

Formulation of the extract of the stem bark of Alstonia boonei as tablet dosage form

Purpose: To formulate the extracts of the stem bark of Alstonia boonei , an important antimalarial herb, into tablet dosage form. Methods: Tablets were formulated using direct compression and wet granulation methods. The mechanical properties of the tablets were assessed using crushing strength and friability and the crushing strength:friability ratio (CSFR) while drug release properties were evaluated using disintegration and dissolution times. Results: There were statistically significant (p<0.01) differences in the CSFR values and drug release properties of A. boonei tablets prepared by both methods. The differences depended on the type and concentration of excipient and binder employed in the formulation. Conclusions: The method of preparation of the A. boonei tablets needs to be carefully selected to ensure the production of tablets with adequate bond strength to withstand the rigours of handling and at the same time release the active compound (s) for biological action

Formulation of the extract of the stem bark of Alstonia boonei as tablet dosage form

Purpose: To formulate the extracts of the stem bark of Alstonia boonei , an important antimalarial herb, into tablet dosage form. Methods: Tablets were formulated using direct compression and wet granulation methods. The mechanical properties of the tablets were assessed using crushing strength and friability and the crushing strength:friability ratio (CSFR) while drug release properties were evaluated using disintegration and dissolution times. Results: There were statistically significant (p<0.01) differences in the CSFR values and drug release properties of A. boonei tablets prepared by both methods. The differences depended on the type and concentration of excipient and binder employed in the formulation. Conclusions: The method of preparation of the A. boonei tablets needs to be carefully selected to ensure the production of tablets with adequate bond strength to withstand the rigours of handling and at the same time release the active compound (s) for biological action