Effects of interacting variables on the release properties of chloroquine and aminophylline suppositories

Purpose: The individual and interaction effects of formulation variables on the release of suppositories were investigated using a 23 factorial experimental design. The variables studied were nature of base (B), type of drug (D), and presence of surfactant (S). Method: Suppositories were formulated with theobroma oil and Witepsol H15 as bases at ‘low' and ‘high' levels respectively. Chloroquine and aminophylline, both water-soluble drugs, were incorporated as active constituents at ‘low' and ‘high' levels respectively while Tween 80 was incorporated as surfactant in some of the formulations. Disintegration time and time taken for 50% of the drug to dissolve were used as assessment parameters. Results: The inclusion of surfactant in the suppository formulation proved to be the most significant variable in the formulation. The ranking for the individual coefficient values for the formulations was S>>B>D for disintegration time DT and S>>>D>B for the dissolution parameter t50. While the ranking for the interaction effects was B-D>B-S>S-D on DT and on t50 S-D>B-S>B-D. Conclusion: The results suggest that in formulating water-soluble drugs such as chloroquine and aminophylline as suppositories in a hydrophobic base, the presence of a surfactant is the most influential variable. Keywords: Suppositories, chloroquine, aminophylline, surfactant, interacting variables. > Tropical Journal of Pharmaceutical Research Vol. 3 (1) 2004: pp. 285-29

Compression, Mechanical and Release Properties of Chloroquine Phosphate Tablets containing corn and Trifoliate Yam Starches as Binders

Purpose: A study was made of the binding properties of trifoliate yam starch, obtained from Dioscorea dumetorum (Pax), in chloroquine phosphate tablet formulations in comparison with official corn starch. Method: Compressional properties were analyzed using density measurements and compression equations of Heckel and Kawakita. The mechanical properties of the tablets were assessed using the crushing strength and friability of the tablets, while drug release properties of the tablets were assessed using disintegration and dissolution times. Results: Tablet formulations containing trifoliate yam starch exhibited faster onset and higher amount of plastic deformation during compression than those containing corn starch. The crushing strength, disintegration and dissolution times of the tablets increased with binder concentration while friability values decreased. Trifoliate yam starch produced tablets with stronger mechanical properties and longer disintegration and dissolution times than those containing corn starch. Conclusion: Trifoliate yam starch would be a better alternative to corn starch in producing uncoated tablets for which high bond strength is essential . Keywords: Trifoliate yam starch, corn starch, binding agent, compression, Heckel equation, Kawakita equation, mechanical properties, drug release> Tropical Journal of Pharmaceutical Research Vol. 5 (2) 2006: pp. 589-59

Investigation of Some Factors Influencing Corrosion on Refrigerator

The corrosion of steel reinforcing bar can proceed out of sight and eventually result in failure of a section of the highway. The collapse of electrical towers, damage to building, leakages in refrigerator all these result in significant repair cost, endangering public safety and health. This paper presents investigation of some factors influencing corrosion on refrigerator, such as presence of dissolved mineral, organic impurities and dissolved gasses in the water. The survey results are presented using graphs. T-test and Anova were used to ascertain the significance of the factors. The result of alternative Hypothesis and null Hypothesis on the T-test and Anova test were carried out on the factors causing corrosion and responsible for the corrosion were able to be identified. The results revealed that the corrosive effect of fresh water varies from locality to locality due to the wide variety of dissolved impurities, the organism causing the greatest corrosion problems are bacteria and fungi, time of exposure to a corrosive environment influences metal corrosion, most salt solution is good electrolyte and can promote corrosive attack and corrosion effects reduce the life span of refrigerator. The result of this research would guide environmental and material engineers in better planning to minimize corrosion

HYPOGLYCEMIC EFFECT OF TRECULIA AFRICANA DECNE ROOT BARK IN NORMAL AND ALLOXAN-INDUCED DIABETIC RATS.

The solvent partitioned purified fractions of the hydro-acetone root bark extract of the African breadfruit (Treculia africana Decne) were evaluated for hypoglycemic activities in normal and diabetic albino rats. Fasting blood glucose levels were estimated by the use of a glucometer at pre-determined intervals after oral administration of the test extracts/fractions. Results revealed that the test fractions have only a slight effect on blood sugar level of normal rats. On short term and chronic administration in diabetic rats however, diethyl ether-soluble (DEF) and the water-soluble (WSF) fractions significantly reduced the fasting blood sugar levels (

Layer-by-layer technique to developing functional nanolaminate films with antifungal activity

The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.The authors acknowledge financial support from FP7 IP project BECOBIOCAP^. M. J. Fabra is recipients of a Juan de la Cierva contract from the Spanish Ministry of Economy and Competitivity. Maria L. Flores-López thanks Mexican Science and Technology Council (CONACyT, Mexico) for PhD fellowship support (CONACyT Grant Number 215499/310847). The author Miguel A. Cerqueira is a recipient of a fellowship (SFRH/BPD/72753/2010) supported by Fundação para a Ciência e Tecnologia, POPH-QREN and FSE (FCT, Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP- 01-0124-FEDER-027462) and the project BBioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,^ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER. The support of EU Cost Action FA0904 is gratefully acknowledged

APOE E4 is associated with impaired self-declared cognition but not disease risk or age of onset in Nigerians with Parkinson's disease

The relationship between APOE polymorphisms and Parkinson's disease (PD) in black Africans has not been previously investigated. We evaluated the association between APOE polymorphic variability and self-declared cognition in 1100 Nigerians with PD and 1097 age-matched healthy controls. Cognition in PD was assessed using the single item cognition question (item 1.1) of the MDS-UPDRS. APOE genotype and allele frequencies did not differ between PD and controls (p > 0.05). No allelic or genotypic association was observed between APOE and age at onset of PD. In PD, APOE ε4/ε4 conferred a two-fold risk of cognitive impairment compared to one or no ε4 (HR: 2.09 (95% CI: 1.13-3.89; p = 0.02)), while APOE ε2 was associated with modest protection against cognitive impairment (HR: 0.41 (95% CI 0.19-0.99, p = 0.02)). Of 773 PD with motor phenotype and APOE characterized, tremor-dominant (TD) phenotype predominated significantly in ε2 carriers (87/135, 64.4%) compared to 22.2% in persons with postural instability/gait difficulty (PIGD) (30/135) and 13.3% in indeterminate (ID) (18/135, 13.3%) (p = 0.037). Although the frequency of the TD phenotype was highest in homozygous ε2 carriers (85.7%), the distribution of motor phenotypes across the six genotypes did not differ significantly (p = 0.18). Altogether, our findings support previous studies in other ethnicities, implying a role for APOE ε4 and ε2 as risk and protective factors, respectively, for cognitive impairment in PD

Antimicrobial and Pharmaceutical Properties of The Seed Oil of Leucaena leucocephala (Lam.) De Wit (Leguminosae)

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

Evaluation of Mucoadhesive Properties of Native and Modified Starches of the Root Tubers of Cocoyam ( Xanthosoma sagittifolium )

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

Sustained Release of a Water-Soluble Drug from Directly Compressed Okra Gum Matrix Tablets

Okra gum was evaluated as a controlled-release agent in modified release matrices in comparison with sodium carboxymethylcellulose (NaCMC) using aspirin as the model drug. Tablets were produced by direct compression and the in vitro drug release was assessed under conditions similar to those in the gastrointestinal system for a period of 6 hours. The hydration (swelling) and erosion rates of the okra gum matrix tablets were also studied. Okra gum matrices provided a controlled-release of aspirin and the release rates followed time-independent kinetics. The addition of the tablet excipients, lactose and Avicel, altered the dissolution profile and release kinetics. Okra gum compared favourably with NaCMC and a combination of okra gum and NaCMC resulted in near zero-order release of aspirin from the matrix tablets. The results indicate that okra gum is suitable for the sustained release of water soluble drugs. Keywords: Okra gum, aspirin, matrix tablet, sustained-release The East and Central African Journal of Pharmaceutical Sciences Vol. 9 (2) 2006: pp. 46-5