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1.
Plants (Basel) ; 13(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38732424

RESUMO

In an era dominated by conventional agricultural practices, underutilized legumes termed "Forgotten Gems" represent a reservoir of untapped benefits with the unique opportunity to diversify agricultural landscapes and enhance global food systems. Underutilized crops are resistant to abiotic environmental conditions such as drought and adapt better to harsh soil and climatic conditions. Underutilized legumes are high in protein and secondary metabolites, highlighting their role in providing critical nutrients and correcting nutritional inadequacies. Their ability to increase dietary variety and food security emerges as a critical component of their importance. Compared to mainstream crops, underutilized legumes have been shown to reduce the environmental impact of climate change. Their capacity for nitrogen fixation and positive impact on soil health make them sustainable contributors to biodiversity conservation and environmental balance. This paper identifies challenges and proposes strategic solutions, showcasing the transformative impact of underutilized legumes on agriculture, nutrition, and sustainability. These "Forgotten Gems" should be recognized, integrated into mainstream agricultural practices, and celebrated for their potential to revolutionize global food production while promoting environmental sustainability.

2.
Heliyon ; 9(4): e15493, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37151618

RESUMO

Legumes are a major food crop in many developing nations. However, orphan or underutilized legumes are domesticated legumes that have valuable properties but are less significant than main legumes due to use and supply restrictions. Compared to other major legumes, they are better suited to harsh soil and climate conditions, and their great tolerance to abiotic environmental circumstances like drought can help to lessen the strains brought on by climate change. Despite this, their economic significance in international markets is relatively minimal. This article is aimed at carrying out a comprehensive review of the nutritional and pharmacological benefits of orphan legumes from eight genera in the sub-family Faboidea, namely Psophocarpus Neck. ex DC., Tylosema (Schweinf.) Torre Hillc., Vigna Savi., Vicia L., Baphia Afzel. ex G. Lodd., Mucuna Adans, Indigofera L. and Macrotyloma (Wight & Arn.) Verdc, and the phytoconstituents that have been isolated and characterized from these plants. A literature search was conducted using PubMed, Google Scholar, and Science Direct for articles that have previously reported the relevance of underutilized legumes. The International Union for Conservation of Nature (IUCN) red list of threatened species was also conducted for the status of the species. References were scrutinized and citation searches were performed on the study. The review showed that many underutilized legumes have a lot of untapped potential in terms of their nutritional and pharmacological activities. The phytoconstituents from plants in the subfamily Faboideae could serve as lead compounds for drug discovery for the treatment of a variety of disorders, indicating the need to explore these plant species.

3.
Polymers (Basel) ; 14(5)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35267857

RESUMO

In the present study, microcrystallinecellulose-colloidal silicon dioxide (MCC-SiO2) and carboxymethylcellulose-colloidal silicon dioxide (CMC-SiO2) conjugates have been investigated as superdisintegrants in fast dissolving tablets (FDTs). MCC-SiO2 and CMC-SiO2 conjugates were prepared and micromeritic studies, FTIR, SEM and XRD methods were utilized for characterizing the powdered conjugates. The conjugates were used for the preparation of domperidone FDTs by direct compression and the wetting time, water absorption ratio, disintegration time and in vitro drug release were evaluated. Effective pore radius of MCC-SiO2 and CMC-SiO2 conjugates for 1:1, 1:2.5 and 1:5 was found to be 13.35 ± 0.31 µm, 15.66 ± 0.17 µm and 18.38 ± 0.44 µm, and 16.81 ± 0.24 µm, 20.12 ± 0.39 µm and 26.37 ± 0.24 µm, respectively, compared to 12.21 ± 0.23 µm for MCC and 13.65 ± 0.21 µm for CMC. The results of effective pore radius indicate the wicking capability as well as the disintegration potential of MCC-SiO2 and CMC-SiO2 conjugates over pure MCC and CMC. The results of wetting time, water absorption ratio and disintegration time for MCC-SiO2 conjugates were found to be in the range of 19 ± 1.21 to 30 ± 1.33 s, 42 ± 0.28 to 49 ± 0.47% and 15 ± 2 to 40 ± 1 s, and for CMC-SiO2 conjugates were found to be in the range of 21 ± 1.13 to 40 ± 1.17 s, 42 ± 0.94 to 49 ± 0.57% and 12 ± 2 to 20 ± 3 s, respectively. Conjugation of MCC and CMC with SiO2 led to the formation of a complex with remarkable tablet superdisintegrant potential that could be used in preparing fast disintegrating tablets.

4.
Int J Biol Macromol ; 79: 226-34, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25940525

RESUMO

Cissus gum has been employed as polymer with sodium alginate in the formulation of diclofenac microbeads and the in vivo mucoprotective properties of the polymer in anti-inflammatory therapy assessed in rats with carrageenan-induced paw edema in comparison to diclofenac powder and commercial diclofenac tablet. A full 2(3) factorial experimental design has been used to investigate the influence of concentration of cissus gum (X1); concentration of calcium acetate (X2) and stirring speed (X3) on properties of the microbeads. Optimized small discrete microbeads with size of 1.22±0.10 mm, entrapment efficiency of 84.6% and t80 of 15.2±3.5 h were obtained at ratio of cissus gum:alginate (1:1), low concentration of calcium acetate (5% w/v) and high stirring speed (400 rpm). In vivo studies showed that the ranking of percent inhibition of inflammation after 3h was diclofenac powder>commercial tablet=cissus>alginate. Histological damage score and parietal cell density were lower while crypt depth and mucosal width were significantly higher (p<0.05) in the groups administered with the diclofenac microbeads than those administered with diclofenac powder and commercial tablet, suggesting the mucoprotective property of the gum. Thus, cissus gum could be suitable as polymer in the formulation of non-steroidal anti-inflammatory drugs ensuring sustained release while reducing gastric side effects.


Assuntos
Alginatos/química , Anti-Inflamatórios não Esteroides/farmacologia , Diclofenaco/farmacologia , Edema/tratamento farmacológico , Microesferas , Gomas Vegetais/química , Acetatos/química , Animais , Anti-Inflamatórios não Esteroides/química , Compostos de Cálcio/química , Carragenina , Preparações de Ação Retardada , Diclofenaco/química , Composição de Medicamentos , Liberação Controlada de Fármacos , Edema/induzido quimicamente , Edema/patologia , Análise Fatorial , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Membro Posterior , Cinética , Masculino , Tamanho da Partícula , Ratos , Estômago/efeitos dos fármacos
5.
J Drug Deliv ; 2014: 827035, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25328710

RESUMO

In the present study, corn Starch-Neusilin UFL2 conjugates were prepared by physical, chemical, and microwave methods with the aim of using the conjugates as tablet superdisintegrant. Various powder tests, namely, angle of repose, bulk density, tapped density, Hausner's ratio, Carr's index, swelling index, and powder porosity were conducted on the samples. The conjugates were characterized by ATR-FTIR, XRD, DSC, and SEM techniques. Heckel and Kawakita models were applied to carry out compression studies for the prepared conjugates. Fast disintegrating tablets of domperidone were prepared using corn starch and corn Starch-Neusilin UFL2 conjugates as tablet superdisintegrants in different concentrations. Conjugates were found to possess good powder flow and tabletting properties. Heckel analysis indicated that the conjugates prepared by microwave method showed the slowest onset of plastic deformation while Kawakita analysis indicated that the conjugates prepared by microwave method exhibited the highest amount of total plastic deformation. The study revealed that the corn Starch-Neusilin UFL2 conjugates possess improved powder flow properties and could be a promising superdisintegrant for preparing fast disintegrating tablet. Also, the results sugessted that the microwave method was found to be most effective for the preparation of corn Starch-Neusilin UFL2 conjugates.

6.
Int J Biol Macromol ; 58: 113-20, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23541556

RESUMO

Four natural gums, namely albizia, cissus, irvingia and khaya gums have been characterized and evaluated as polymers for the formulation of microbeads for controlled delivery of diclofenac sodium. The natural gums were characterized for their material properties using standard methods. Diclofenac microbeads were prepared by ionotropic gelation using gel blends of the natural gums and sodium alginate at different ratios and zinc chloride solution (10%w/v) as the crosslinking agent. The microbeads were assessed using SEM, swelling characteristics, drug entrapment efficiencies and release properties. Data obtained from in vitro dissolution studies were fitted to various kinetic equations to determine the kinetics and mechanisms of drug release, and the similarity factor, f2, was used to compare the different formulations. The results showed that the natural gum polymers varied considerably in their material properties. Spherical and discrete microbeads with particle size of 1.48-2.41 µm were obtained with entrapment efficiencies of 44.0-71.3%w/w. Drug release was found to depend on the type and concentration of polymer gum used with formulations containing gum:alginate ratio of 3:1 showing the highest dissolution times. Controlled release of diclofenac was obtained over for 5h. Drug release from the beads containing the polymer blends of the four gums and sodium alginate fitted the Korsmeyer-Peppas model which appeared to be dependent on the nature of natural gum in the polymer blend while the beads containing alginate alone fitted the Hopfenberg model. Beads containing albizia and cissus had comparable release profiles to those containing khaya (f2>50). The results suggest that the natural gums could be potentially useful for the formulation controlled release microbeads.


Assuntos
Albizzia/química , Cissus/química , Portadores de Fármacos/química , Meliaceae/química , Microesferas , Gomas Vegetais/química , Anti-Inflamatórios não Esteroides/química , Varredura Diferencial de Calorimetria , Preparações de Ação Retardada/química , Diclofenaco/química , Meia-Vida , Cinética , Magnoliopsida/química , Tamanho da Partícula , Porosidade , Difração de Raios X
7.
Saudi Pharm J ; 20(2): 171-5, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23960789

RESUMO

Acid modified starches obtained from two species of yam tubers namely white yam - Dioscorea rotundata L. and water yam - D. alata L. DIAL2 have been investigated as intra- and extra-granular disintegrants in paracetamol tablet formulations. The native starches were modified by acid hydrolysis and employed as disintegrant at concentrations of 5 and 10% w/w and their disintegrant properties compared with those of corn starch BP. The tensile strength and drug release properties of the tablets, assessed using the disintegration and dissolution (t 50 and t 80 - time required for 50% and 80% of paracetamol to be released) times, were evaluated. The results showed that the tensile strength and the disintegration and dissolution times of the tablets decreased with increase in the concentration of the starch disintegrants. The acid modified yam starches showed better disintegrant efficiency than corn starch in the tablet formulations. Acid modification appeared to improve the disintegrant efficiency of the yam starches. Furthermore, tablets containing starches incorporated extragranularly showed faster disintegration but lower tensile strength than those containing starches incorporated intragranularly. This emphasizes the importance of the mode of incorporation of starch disintegrant.

8.
AAPS PharmSciTech ; 13(1): 16-23, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22068290

RESUMO

The exudates from the incised trunk of Terminalia randii has been evaluated as controlled release excipient in comparison with xanthan gum and hydroxypropylmethylcellulose (HPMC) using carvedilol (water insoluble) and theophylline (water soluble) as model drugs. Matrix tablets were prepared by direct compression and the effects of polymer concentration and excipients-spray dried lactose, microcrystalline cellulose and dicalcium phosphate dihydrate on the mechanical (crushing strength (CS) friability (F) and crushing strength-friability ratio (CSFR)) and drug release properties of the matrix tablets were evaluated. The drug release data were fitted into different release kinetics equations to determine the drug release mechanism(s) from the matrix tablets. The results showed that the CS and CSFR increased with increase in polymer concentration while F decreased. The ranking of CS and CSFR was HPMC > terminalia > xanthan while the ranking was reverse for F. The ranking for t(25) (i.e. time for 25% drug release) at a polymer concentration of 60% was xanthan > terminalia = HPMC. The dissolution time, t(25), of theophylline matrices was significantly lower (p < 0.001) than those of carvedilol matrix tablets. Drug release from the matrices was by swelling, diffusion and erosion. The mechanical and drug release properties of the tablets were significantly (p < 0.05) dependent on the type and concentration of polymer and excipients used with the release mechanisms varying from Fickian to anomalous. Terminalia gum compared favourably with standard polymers when used in controlled release matrices and could serve as a suitable alternative to the standard polymers in drug delivery.


Assuntos
Força Compressiva , Excipientes/química , Gomas Vegetais/química , Terminalia , Carbazóis/administração & dosagem , Carbazóis/química , Carbazóis/metabolismo , Carvedilol , Sistemas de Liberação de Medicamentos , Excipientes/administração & dosagem , Excipientes/metabolismo , Gomas Vegetais/administração & dosagem , Gomas Vegetais/metabolismo , Propanolaminas/administração & dosagem , Propanolaminas/química , Propanolaminas/metabolismo , Comprimidos
9.
Asian Pac J Trop Med ; 4(8): 632-6, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21914541

RESUMO

OBJECTIVE: To explore the antidiabetic properties of Mucuna pruriens(M. pruriens). METHODS: Diabetes was induced in Wistar rats by single intravenous injection of 120 mg/kg of alloxan monohydrate and different doses of the extract were administered to diabetic rats. The blood glucose level was determined using a glucometer and results were compared with normal and untreated diabetic rats. The acute toxicity was also determined in albino mice. RESULTS: Results showed that the administration of 5, 10, 20, 30, 40, 50, and 100 mg/kg of the crude ethanolic extract of M. pruriens seeds to alloxan-induced diabetic rats (plasma glucose > 450 mg/dL) resulted in 18.6%, 24.9%, 30.8%, 41.4%, 49.7%, 53.1% and 55.4% reduction, respectively in blood glucose level of the diabetic rats after 8h of treatment while the administration of glibenclamide (5 mg/kg/day) resulted in 59.7% reduction. Chronic administration of the extract resulted in a significant dose dependent reduction in the blood glucose level (P<0.001). It also showed that the antidiabetic activity of M. pruriens seeds resides in the methanolic and ethanolic fractions of the extract. Acute toxicity studies indicated that the extract was relatively safe at low doses, although some adverse reactions were observed at higher doses (8-32 mg/kg body weight), no death was recorded. Furthermore, oral administration of M. pruriens seed extract also significantly reduced the weight loss associated with diabetes. CONCLUSIONS: The study clearly supports the traditional use of M. pruriens for the treatment of diabetes and indicates that the plant could be a good source of potent antidiabetic drug.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Mucuna/química , Fitoterapia/métodos , Extratos Vegetais/administração & dosagem , Administração Oral , Aloxano/efeitos adversos , Animais , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Relação Dose-Resposta a Droga , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Glibureto/farmacologia , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/uso terapêutico , Masculino , Camundongos , Extratos Vegetais/efeitos adversos , Extratos Vegetais/uso terapêutico , Ratos , Ratos Wistar , Sementes/química
10.
Asian Pac J Trop Med ; 4(4): 283-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21771471

RESUMO

OBJECTIVE: To investigate the antiplasmodial activity of the extracts of Phyllanthus amarus (P. amarus) on Plasmodium yoelii (P. yoelii) (a resistant malaria parasite strain used in animal studies) infection in mice. METHODS: The aqueous and ethanol extracts of the whole plant of Phyllanthus amarus was administered to Swiss albino mice at doses of 200 mg/kg/day, 400 mg/kg/day, 800 mg/kg/day and 1600 mg/kg/day and the prophylactic and chemotherapeutic effect of the extracts against P. yoelii infection in mice was investigated and compared with those of standard antimalaria drugs used in the treatment of malaria parasite infection. Acute toxicity test was carried out in mice to determine the safety of the plant extract when administered orally. RESULTS: The results showed that the extracts demonstrated a dose-dependent prophylactic and chemotherapeutic activity with the aqueous extracts showing slightly higher effect than the ethanol extract. The antiplasmodial effects of the extracts were comparable to the standard prophylactic and chemotherapeutic drugs used in chloroquine resistant Plasmodium infection although the activity depended on the dose of the extract administered. The extracts showed prophylactic effect by significantly delaying the onset of infection with the suppression of 79% at a dose of 1600 mg/kg/day. CONCLUSIONS: The results obtained indicate that the extracts of the whole plant of P. amarus possess repository and chemotherapeutic effects against resistant strains of P. yoelii in Swiss albino mice. The findings justify the use of the extract of P. amarus in traditional medicine practice, for the treatment of malaria infections.


Assuntos
Antimaláricos/isolamento & purificação , Malária/tratamento farmacológico , Malária/prevenção & controle , Phyllanthus/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Plasmodium yoelii/efeitos dos fármacos , Animais , Antimaláricos/administração & dosagem , Antimaláricos/farmacologia , Cápsulas/administração & dosagem , Química Farmacêutica , Quimioprevenção/métodos , Modelos Animais de Doenças , Feminino , Malária/parasitologia , Masculino , Camundongos , Extratos Vegetais/administração & dosagem
11.
Saudi Pharm J ; 19(2): 95-105, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23960747

RESUMO

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 formulation.

12.
Org Lett ; 12(2): 252-5, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-20000624

RESUMO

Grandifotane A (1), a limonoid with an unprecedented carbon skeleton, was isolated from the stem bark of Khaya grandifoliola. The structure of 1 with the absolute configuration was determined by spectroscopic data, X-ray crystallography, and ECD calculation. A biogenetic route for grandifotane A (1) involving an enzymatic Baeyer-Villiger oxidation as the key step is proposed.


Assuntos
Limoninas/química , Meliaceae/química , Animais , Dicroísmo Circular , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular
13.
Drug Dev Ind Pharm ; 35(11): 1389-406, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19832640

RESUMO

Starches obtained from four different Dioscorea species-namely, White yam (Dioscorea rotundata), Bitter yam (Dioscorea dumetorum), Chinese yam (Dioscorea oppositifolia), and Water yam (Dioscorea alata)-were modified by cross-linking, hydroxypropylation, and dual modification-cross-linking followed by hydroxypropylation. The physicochemical, material, and tablet properties of the modified starches were investigated with the aim of understanding their properties to determine their potential use for different applications. The tablet formation properties were assessed using 3D modeling, the Heckel equation, and force-displacement profiles. The analyzed tablet properties were elastic recovery, compactibility, and disintegration. The result indicates that the modifications generally increased the swelling power for all the starches in the rank order hydroxypropyl > hydroxypropylated cross-linked > cross-linked (CL) while the solubility did not show a clear-cut pattern. This indicates that hydroxypropylation generally showed the strongest effects on swelling. Furthermore, hydroxypropylation improved the hot water swelling of the CL starches. The modifications did not cause any detectable morphological change in the starch granules shape or size although slight rupture was observed in some granules. CL starch had the lowest water sorption capacity and hydroxypropylation increased the sorption capacity of the CL starches. The material property results indicate that hydroxypropylation and cross-linking did not significantly improve the flowability and compressibility but improved bonding, which resulted in an increased compaction and higher tablet crushing force even though they all disintegrated rapidly. Thus, the modified Dioscorea starches showed potentials for development as new excipients in solid dosage form design, and they could be useful as disintegrants or for Soft tableting.


Assuntos
Reagentes de Ligações Cruzadas/química , Dioscorea/química , Composição de Medicamentos/métodos , Excipientes/química , Amido/química , Comprimidos/química , Varredura Diferencial de Calorimetria , Elasticidade , Compostos de Epóxi/química , Excipientes/isolamento & purificação , Teste de Materiais , Microscopia Eletrônica de Varredura , Modelos Químicos , Tamanho da Partícula , Difração de Pó , Solubilidade , Análise Espectral Raman , Amido/isolamento & purificação , Propriedades de Superfície , Água/análise
14.
Pharm Dev Technol ; 14(3): 259-70, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19519180

RESUMO

Starches obtained from four different Dioscorea species namely White (D. rotundata), Bitter (D. dumetorum), Chinese (D. oppositifolia) and Water yam (D. alata), were modified by acid hydrolysis and the physicochemical, material and tablet formation properties of the starches were investigated with the aim of determining their usefulness as a direct compression excipient in pharmaceutical tablets. The results obtained indicate that the physicochemical, material and tablet properties of the acid modified Dioscorea starches varied considerably among the various species. Acid hydrolysis led to an increase in solubility but decrease in swelling of the starches. Acid modification also led to an increase in the compressibility of the starches when compared with the native forms of the starches. Acid modified Water and White formed intact stable tablets only at higher rho(rel,) (max), while acid modified Chinese and Bitter formed tablets at all relative densities which could already be predicted from the deformation behaviour as analyzed by 3-D modeling. The result indicates that acid modified starch tablets showed higher crushing force and acceptable disintegration time and could therefore be useful as directly compressible excipient.


Assuntos
Dioscorea/química , Excipientes/química , Amido/química , Ácidos/química , Hidrólise , Comprimidos/química
15.
Pharm Dev Technol ; 13(6): 473-80, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18720239

RESUMO

A study was made of the comparative effects of polymers obtained from two species of khaya tree - Khaya senegalensis and Khaya grandifoliola - as binding agents in a paracetamol tablet formulation. The mechanical properties of the tablets were assessed using the tensile strength (T), brittle fracture index (BFI) and friability (F) of the tablets while the drug release properties of the tablets were assessed using disintegration and dissolution times. The tensile strength, disintegration and the dissolution times of tablets increased with the increase in binder concentration while F and BFI decreased. K. senegalensis gum produced tablets with stronger mechanical properties with less tendency to laminate, and longer disintegration and dissolution times than K. grandifoliola gum. The results suggest that the polymer gum from K. senegalensis will be more appropriate as a binding agent than the gum from K. grandifoliola when higher mechanical strength and slower release profiles of tablets are desired.


Assuntos
Acetaminofen/química , Meliaceae/química , Gomas Vegetais/química , Acetaminofen/farmacocinética , Algoritmos , Analgésicos não Narcóticos/química , Analgésicos não Narcóticos/farmacocinética , Excipientes/química , Concentração de Íons de Hidrogênio , Lactose/química , Amido/química , Comprimidos , Resistência à Tração , Viscosidade , Água/química
16.
Eur J Pharm Biopharm ; 70(1): 357-71, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18562187

RESUMO

The material and tablet formation properties of pregelatinized (thermally modified) forms of four Dioscorea starches have been investigated. Dioscorea starches were pregelatinized followed by either oven drying (PS) or freeze drying (FD) and used as excipient in direct compression. The physicochemical, morphological and material properties of the pregelatinized starches have been investigated. The tablet formation properties were assessed using the 3-D modeling parameters, the Heckel equation and the force-displacement profiles. The tablet properties were evaluated using the elastic recovery, compactibility plots and the disintegration test. The results indicate that pregelatinization improved the compressibility and flowability of the Dioscorea starches. The high bulk and tap densities of PS coupled with their good flowability offer a unique possibility of the starches being used as filler in capsule formulations. The modified starches generally showed differences in their time and pressure dependent deformation behaviour. PS exhibited higher elasticity during tableting. FD Chinese and FD Bitter showed higher plasticity and low fast elastic deformation than the PS forms of the starches indicating that the FD starches undergo the highest plastic deformation. However, FD starches generally showed higher compactibility compared to the PS forms of the Dioscorea starches. While FD White and FD Water showed fast disintegration time and high compactibility, FD Chinese and FD Bitter were non-disintegrating and showed high compactibility. The high compactibility observed with the FD starches appears to be as a result of material change occurring during tableting probably due to the effect of temperature or pressure or a combination of both factors. Thus, FD White and FD Water starches could be useful when high crushing force and fast disintegration are of concern while FD Chinese and FD Bitter, which were non-disintegrating, could find application as excipients for controlled drug delivery.


Assuntos
Dioscorea , Excipientes/química , Amido/química , Temperatura , Química Farmacêutica , Preparações de Ação Retardada , Dessecação , Dioscorea/química , Elasticidade , Excipientes/isolamento & purificação , Liofilização , Teste de Materiais , Modelos Químicos , Tubérculos , Pressão , Reologia , Solubilidade , Amido/isolamento & purificação , Comprimidos , Tecnologia Farmacêutica/métodos
17.
Phytochemistry ; 69(1): 271-5, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17655891

RESUMO

Three limonoids, deacetylkhayanolide E (1), 6S-hydroxykhayalactone (2), and grandifolide A (3), along with three known ones, were isolated from stem bark of the Nigerian medicinal plant Khaya grandifoliola. Their structures were characterized on the basis of the application of spectroscopic methods. In vitro antimicrobial and cytotoxic activities of the isolates were also tested, but were all found to be inactive.


Assuntos
Limoninas/química , Meliaceae/química , Casca de Planta/química , Caules de Planta/química , Animais , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Limoninas/farmacologia , Limoninas/toxicidade , Espectroscopia de Ressonância Magnética , Camundongos , Testes de Sensibilidade Microbiana
18.
Pharm Dev Technol ; 11(4): 435-41, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17101514

RESUMO

A study has been made of the compression properties of khaya gum matrices and the effects of drug concentration and method of preparation of the material on the compression, mechanical and the drug release characteristics of the matrices. Khaya gum matrix tablets were prepared by direct compression and wet granulation methods. The compression properties of the formulations were assessed using the equations of Heckel and Kawakita. The mechanical properties of the tablets were evaluated using crushing strength and friability of the tablets, whereas the release properties of the tablets were evaluated by using the disintegration and dissolution times. The results obtained show that khaya gum deformed mainly by plastic deformation. The compression properties of the formulations were affected by the concentration of the drug and the method of preparation of the materials for compression. Tablets prepared by wet granulation showed faster onset and higher amount of plastic deformation during compression than those prepared by direct compression. Tablets containing dicalcium phosphate showed higher mechanical strength and disintegration and dissolution times. Wet granulation also increased the mechanical strength of the tablet without significantly affecting the drug release characteristics from the matrix tablets. Thus, the wet granulation method could be useful in the preparation of khaya gum matrix tablet with acceptable mechanical properties and drug release properties.


Assuntos
Goma de Karaya/farmacocinética , Teste de Materiais/métodos , Fosfatos de Cálcio , Força Compressiva , Mecânica , Métodos , Farmacocinética , Solubilidade , Comprimidos
19.
Drug Dev Ind Pharm ; 32(3): 357-65, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16556540

RESUMO

A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T--a measure of bond strength) and brittle fracture index (BFI--a measure of lamination tendency). The ranking for the mean yield pressure, P(y), for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for P(k), an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.


Assuntos
Acetaminofen/química , Cajanus/química , Musa/química , Amido/química , Química Farmacêutica , Força Compressiva , Relação Dose-Resposta a Droga , Frutas , Sementes , Solubilidade , Comprimidos , Resistência à Tração
20.
AAPS PharmSciTech ; 6(3): E458-63, 2005 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-16354005

RESUMO

The effects of plantain starch obtained from the unripe fruit of the plant Musa 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 2(3) 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.


Assuntos
Acetaminofen/química , Musa , Amido/química , Zea mays , Musa/química , Solubilidade , Estresse Mecânico , Comprimidos com Revestimento Entérico , Zea mays/química
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