Purpose: To evaluate the physicochemical and in vitro characteristics of solid dispersions using BCS II model drugs with Soluplus® and one of its component homopolymers, PEG 6000. Methods: Nifedipine ...(NIF) and sulfamethoxazole (SMX) of 99.3% and 99.5% purity, respectively, were selected as BCS II model drugs, such that an improved dissolution rate and concentration in the gastrointestinal tract should increase oral bioavailability. Soluplus® is an amorphous, tri-block, graft co-polymer with polyvinyl caprolactam, polyvinyl acetate, and polyethylene glycol (PCL:PVAc:PEG6000) in the ratio 57:30:13. PEG 6000 (BASF) is a waxy material with melting point of about 60°C. Solid dispersions were prepared using lyophilization or spray drying techniques. Dissolution study, crystallinity content, and analysis for new chemical bond formation have been used to evaluate the dispersed materials. Results: Although each polymer improved the drug dissolution rate, dissolution from Soluplus® was slower. Enhanced dissolution rates were observed with NIF solid dispersions, but the dissolution profiles were quite different due to the selected technique, polymer, and dissolution medium. For SMX, there was similarity across the dissolution profiles despite the medium, polymer, or applied technique. Each polymer was able to maintain an elevated drug concentration over the three hour duration of the dissolution profile, i.e., supersaturation was supported by the polymer. DSC thermograms revealed no melting endotherm, suggesting that the drug is amorphous or molecularly dispersed. Conclusion: NIF and SMX solid dispersions were successfully prepared by spray drying and lyophilization using Soluplus® or PEG 6000. Each polymer enhanced the drug dissolution rate; NIF dissolution rate was improved to a greater extent. Dispersions with PEG 6000 had a faster dissolution rate due to its hydrophilic nature. DSC analysis showed that no crystalline material exists in the dispersions.
Objective: The present study was aimed to enhance the solubility of poorly water-soluble drug (BCS Class II) Febuxostat using water-soluble polymers.Methods: Pre-formulation studies like drug ...excipient compatibility studies by Fourier-transform infrared spectroscopyDifferential scanning calorimetry and determination of saturation solubility of drug individually in various media like distilled water and pH 7.4 phosphate buffer. Solid dispersions of Febuxostat was prepared using Polyethylene glycol (PEG 6000) (fusion method) and Polyvinyl pyrrolidone (PVP K30) (solvent evaporation method) in various ratios like 1:1, 1:2, 1:3 and 1:4 separately. The formulated solid dispersions were evaluated for percentage yield, drug content and in vitro dissolution studies.Results: From the results of pre-formulation studies it was revealed that there was no interaction between drug and excipients and the pure drug was poorly soluble in water. The percentage yield of all formulations was in the range of 54-78 %, and drug content was in the range of 43-78 mg. The solid dispersion containing polyvinylpyrrolidone K 30 in 1:4 ratio showed the highest amount of drug release at the end of 30 min than other formulations.Conclusion: Finally it was concluded that solid dispersion prepared with PVP K-30 in 1:4 ratio by solvent evaporation method was more soluble than by fusion method.
Abstract The objective of this work was to characterize the effect of the osmotic potential of the culture medium on the control of direct somatic embryogenesis in coffee (Coffea arabica) tree. Leaf ...explants of the Mundo Novo cultivar and four hybrids were subjected to the direct route in the presence of polyethylene glycol 6000, at the following concentrations: 0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0%. Embryogenic structures and somatic embryos were formed at a threshold osmotic potential of up to -0.691 and -0.374 MPa, respectively, with a reduction or inhibition in these responses under a more negative osmotic potential.
Resumo O objetivo deste trabalho foi caracterizar o efeito do potencial osmótico do meio de cultura no controle da embriogênese somática direta em cafeeiro (Coffea arabica). Explantes foliares da cultivar Mundo Novo e de quatro híbridos foram submetidos à via direta na presença de polietilenoglicol 6000, nas seguintes concentrações: 0, 2,5, 5,0, 7,5, 10,0, 12,5 e 15,0%. Estruturas embriogênicas e embriões somáticos formaram-se no potencial osmótico limite de até -0,691 e -0,374 MPa, respectivamente, com redução ou inibição destas respostas nos potenciais osmóticos mais negativos.
Drought is a restraining factor for the major dependent factors like yield. Pertaining to this issue, analyzing the drought potential of the sweet corn is a major concern. The present investigation ...was carried out to reveal the drought tolerant potential of sweet corn genotypes by invitro screening under four levels of osmotic stress (0, -2, -4 and -6 bar) using PEG. The material used for the study included six lines and five testers and their corresponding thirty hybrids synthesized in a line x tester mating design. The seedlings exhibited a significant variation for all the traits and indices analyzed. Under high stress, SVI of the selected entries were found to be higher because of increase in germination percentage and seedling length which would ultimately lead to better field emergence. Performance of the hybrids WNC12039-1× 45503, WNC12039-1×45678 and SC11-2×45679 excelled over the commercial check i.e. Misthi when subjected to lower water potential. Based on the preliminary study, the identified inbreds WNC 12069-2, SC 11-2 and the hybrids WNC12039-1×45503, WNC12039-1×45678 and SC11-2×45679 could be further evaluated in the field.
Background: Blackgram is one of the important pulse crops belongs to the Papilionaceae family. Seed germination and seedling growth are a very important step in the survival of a plant. Water stress ...is one of the important factors affects seedling growth.
Methods: An experiment was conducted to study the effect of water stress on seedling growth in twenty-one blackgram Vigna mungo (L.) Hepper genotypes at the pot culture yard of Annamalai University during March 2018. The water stress was created by using Polyethylene Glycol (6000 MW) in different concentrations (0%, 10% and 20%). Different phenotypic characters were recorded such as shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight at two different levels of treatment and control. The experiment was laid in a completely randomized design with two replications.
Result: The combined analysis of variance revealed significant differences (p less than 0.001) among genotypes, treatments and genotypes × treatments interaction. The highest stress tolerance index (STI) was recorded by the genotype ADT-5. Based on clustering and ranking, the genotypes ADT-5, KGB-28, RU-16-9, VBG-10010 and VBG-12062 were classified as drought-tolerant. Overall, pot culture screening of 21 blackgram genotypes for drought tolerance at seedling stage using various concentrations of PEG 6000 resulted in the identification of drought-tolerant genotypes, where ADT-5 showed the highest tolerance followed by KGB-28 and RU-16-9.
In the present investigation, a total of 50 indigenous rice genotypes collected from rice growing regions of Tamil Nadu were screened for their drought tolerance ability. The experimental setup ...comprises of hydroponic treatments with different levels of osmotic potential, upto (-) 15 bars in a progressive manner. Phenotypic responses showed that,30% of the landraces tested were highly susceptible and only 12% were highly tolerant to moisture stress on 26 DAS. The germination percent (GP) was significantly varied between 0.83 to 1.14 for stress (S) and control treatments respectively. The genotypes viz., kuliyadichan and rajalakshmi recorded high germination percent (1.18) compared to other land races under moisture stress condition. The significant mean root length varied from 10.65cm to 4.05cm and 13.65cm to 5.60cm at an OP of (-) 15 bars and control respectively. Similarly, the significant mean shoot length varied from 24.15 cm to 7.35cm under moisture stress ((-) 15 bars) and 38.25cm to 17.15cm under control. The highest R/S ratio was observed in kuliyadichan (0.87) while the lowest ratio was recorded by the genotype annada (0.18) at OP of (-) 15 bars. In addition, high SHR ratio (120.26) was also recorded for kuliyadichan and low SHR (8.99) for virendra. These results suggest that the genotypes kuliyadichan, chandaikar, mallikar, mattaikar, rajalakshmi and nootripattu represent better source-sink relationship. It is concluded that these genotypes can be used as donor candidates towards genetic improvement of drought tolerance (DT) in rice.
Abstract Background Cutleaf geranium ( Geranium dissectum L) is a weed found in cereals and grasslands. Knowledge about the germination response of weeds under various environmental conditions is ...critical for their effective management, whereas such study has not been carried out thoroughly on this species. Objective This study was carried out to investigate the effect of some environmental factors on seed germination and emergence of cutleaf geranium. Methods The seeds were subjected to various environmental factors including water potentials, salinity, pH, high temperatures, burial depth and flooding at the temperature resulting in the highest germination (10 °C). All experiments were carried out twice, which were done consecutively. Results Germination percentage was halved at a water potential of -0.6 MPa, and no germination was observed at -2 MPa. Geranium dissectum seeds had negligible germination at 200 mM NaCl concentration. Seeds germinated over a pH range of 5-8, with the highest germination at pH between 6 and 7. Germination of this species reached from 85.0% after treatment at 80 °C but no seeds germinated after exposure to 120 °C. Maximum emergence was estimated 88.8%, which was halved at 2.2 cm depth. No emergence was observed at 4 cm or greater depths. Germination was 88.4% to 0% 15 days after flooding. Conclusions This species may not usually be found in areas with poor environmental conditions, and a semi-deep tillage or inclusion of rice in crop rotation may be used to control this weed.
A espécie florestal Toona ciliata var. australis possui madeira de alto valor econômico para móveis e seus plantios não são afetados pela Hypsipyla grandella, praga que ataca plantios de monocultura ...de espécies nativas semelhantes à Toona ciliata. Possui uma estreita relação com a água disponível, ocorrendo geralmente em florestas úmidas no seu ambiente natural. Em plantios comerciais esse é um dos fatores que mais limita seu estabelecimento e crescimento inicial. Nas últimas décadas, sua área de plantio no Brasil foi ampliada, entretanto, é escasso o conhecimento sobre o efeito de ambientes adversos na germinação e crescimento inicial de plântulas. O objetivo deste trabalho foi avaliar os efeitos do estresse salino e hídrico na germinação e crescimento inicial de plântulas de Toona ciliata, utilizando-se soluções contendo, ou NaCl, ou PEG 6000, nos potenciais osmóticos: -0,1; -0,2; -0,3; -0,4; -0,5; -0,6; -0,9; -1,2 e -1,5 MPa, mais a testemunha, com água esterilizada. As sementes foram submetidas ao teste de germinação sobre papel-germitest umedecido com a solução correspondente, e incubadas a 25 ± 2°C e fotoperíodo de 16 h por 21 dias. O delineamento experimental foi o inteiramente casualizado, arranjado em esquema fatorial 2 × 10 (agentes osmóticos × potenciais osmóticos e testemunha), com quatro repetições de 50 sementes cada. Conforme a redução do potencial osmótico observou-se menor germinação, número de plântulas normais, massa fresca, comprimento de plântula e maior número de sementes duras, sendo mais severo em PEG 6000. Portanto, houve mais sementes germinadas sob o efeito do NaCl do que do PEG 6000. Entretanto, apesar da germinação alta em NaCl, o número de plântulas anormais também foi maior que em PEG 6000. Conclui-se que a germinação e o crescimento inicial de plântulas de Toona ciliata são afetados tanto pelo estresse salino como hídrico, sendo as plântulas mais sensíveis ao estresse hídrico, e com maior probabilidade de desenvolver plântulas anormais sob estresse salino.
The aim of the work was to study the impact of drought on the millet (Panicum miliaceum L.) seed germination and morphological parameters of seedlings and to identify millet genotypes with balanced ...rhizo- and organogenesis under arid conditions. Since the soil drought weakens plant immunity during seed germination and provokes development of various diseases, especially smut (Sorosporium destruens (Schlecht) Yanki), it is necessary to identify plant genotypes with high resistance to virulent smut races. We studied resistance of 28 millet varieties to 13 smut races registered in Ukraine. The osmotic PEG 6000 (23 %) was used to simulate soil drought during the seed germination. After six days of incubation, seed germinability was assessed and the length of shoots and roots of seedlings was measured. The stress resistance of millet varieties was evaluated by the root length/shoot length ratio (R/S). Water deficit in the soil decreased seed germinability to 50.12 %. Morphological changes were more pronounced in shoots (decrease in length by 77.3 %) than in roots (decrease by 37.7 %). Under favorable weather conditions, the rhizo- and organogenesis in seedlings was even (R/S=0.75±0.02). In case of soil drought, the ratio R/S dropped to 2.19±0.03. Most of the varieties were resistant to smut races Rs 1, Rs 5–Rs 7, and Rs 9–Rs 11; in addition, around 10 % of the studied varieties was highly resistant (9–8 points) to smut races Rs 2, Rs 8, Rs 12, and Rs 13. Millet genotypes resistant to Rs 3 smut race were not found. Thus, the varieties with R/S ratio around one and higher should be considered the most valuable genetic material in selection for drought resistance. High R/S ratios were observed in the varieties Zapovitne (1.77), Zolushka (1.54), Olitan (1.4), Skado (1.79) and Danilo (1.79). The varieties Olitan and Danilo were highly resistant to the smut races Rs 1, Rs 4, Rs 7, Rs 9–Rs 11, while the varieties Novokyivske 0.1 (2.17) and Konstantynivske (2.22) to the smut races Rs 1, Rs 4–Rs 7, Rs 9–Rs 12. The variety Bila Altanka was not affected by the most virulent smut races Rs 2, Rs 8 and Rs 13. We recommend to include these millet genotypes in selection for drought and smut resistance.
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