Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 22

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Introduction: Dandelion (Taraxacum officinale coll.), also called the common dandelion grows wild throughout Europe, Asia and the Americas. It is a perennial plant of the family of Asteraceae, having powerful healing properties. The entire plant – flowers, roots and leaves – is the medicinal raw material. Objective: The aim of this study was to manufacture model tablets of pharmacopoeial disintegration time by direct compression of dry titrated extract of dandelion with selected excipients. Methods: Tablets were obtained by direct compression using reciprocating tableting machine (Erweka). Morphological parameters – hardness, friability, disintegration time in pharmacopoeial acceptor fluids were investigated using Erweka equipment. Their actual surface area was also calculated. There was also tested the rate of dissolution of phytochemicals from model tablets in the presence of excipients in pharmacopoeial acceptor fluids ( V=1.0 dm3) by the method of a basket in Erweka apparatus. Spectrophotometric determinations were performed. Results: It results from the morphological studies of model tablets containing Ext. Taraxaci e radix cum herba aqu. siccum that they are characterized by comparable surface and friability at varying hardness, the latter depending on the applied excipients. This is reflected in the effective disintegration time in model acceptor fluids consistent with pharmacopoeial requirements. Conclusions: The used excipients enabled to produce model tablets containing dry extract of dandelion by direct compression. The obtained results demonstrated that microcrystalline Prosolv-type cellulose, Vivapur 200 and Emdex were compatible with the structure of the extract of dandelion. They allow to manufacture a model solid oral dosage forms of the desired morphological parameters and effective disintegration time complying with the pharmacopoeial requirements.
It has been decided to investigate the usefulness of selected acrylic acid polymers (Carbopols), chitosan and microcrystalline cellulose as dominating carriers of dry extract from ginger rhizome (Zingiber officinale Rosc.) in an oral solid form of a drug. The aim of the study was to obtain tablets in the course of direct tableting of controlled release of biologically active substances. Seven batches of tablets were manufactured in reciprocating instrumented tableting machine and the effect of the kind of applied adjuvant substances on the rate of biologically active substances release from the produced tablets was evaluated. Physicochemical parameters were determined in order to test the produced tablets. The tablets containing acrylic acid polymers (Carbopol 71 GNF, Carbopol 974 PNF) demonstrated the highest hardness. The tests of pharmaceutical availability of biologically active substances from tablets to the acceptor fluid 0,1 mol/l HCl and comparatively to hydrating intervention hypotonic fluid and to pediatric compensating fluid were performed. The investigations fulfilled general and detailed requirements of Polish Pharmacopoeia VII. Tablets containing Carbopol 71 GNF as dominating carrier of the extract, Vivapur 112 and Prosolv HD 90 demonstrated high pharmaceutical availability. Introduction of Prosolv SMCC 50 together with dominating carriers of the extract had a beneficial effect on pharmaceutical availability of biologically active substances from the tested tablets. It results from the carried out investigations that the kind of the applied adjuvant substances and differentiated osmolarity of model acceptor fluids significantly decide on pharmaceutical availability of hydrophilic therapeutic agents contained in dry extract from ginger rhizome. The adjuvant substances applied in adequate proportions appeared to be useful for manufacturing tablets containing dry extract from ginger rhizome.
Introduction: The general Hildebrand-Scatchard theory of solubility supplemented by Fedors’ solubility parameter was used to estimate the real solubility by -log x2 (log of the mole fraction) of phytochemicals contained in Ext. Taraxaci e radix cum herba aqu. siccum. Surface activity of aqueous solution of extracts was determined and quantified – solubilizing capabilities of solutions of cexp. ≥cmc in relation to cholesterol particle size of Ø=1.00 mm, as well as of ketoprofen were defined. Objective: The calculated value -log x2 collated with the polarity of extraction medium εM allows to estimate the optimal solubility of phytochemicals that determine the viscosity of the aqueous extract of dandelion and above all its surface activity and the ability to solubilize lipophilic therapeutic agents (ketoprofen). Methods: Viscosity of water model solutions of dandelion extracts and exhibition solutions after the effective micellar solubilization of cholesterol and ketoprofen was measured using Ubbelohde viscometer in accordance with the Polish Standard. The surface tension of aqueous solutions of extract and exhibition solutions after solubilization of cholesterol and ketoprofen was measured according to the Polish Standard with stalagmometric method. Results: The calculated factual solubility, and mainly the determined and calculated hydrodynamic size mean, that despite the complex structure of the micelle, it solubilizes cholesterol (granulometric grain of diameter Ø=1.00 mm) and ketoprofen (state of technological fragmentation) in equilibrium conditions. Equilibrium solubilization of ketoprofen also occurs in an environment of model gastric juice (0.1 mol HCl). Conclusions: The obtained results indicate that after the administration (and/or dietary supplementation) with Ext. Taraxaci e radix cum herba aqu. siccum, the physiological parameters of gastric juice would not be measured and its presence (phytosurfactant) in the body of the duodenum (bile A) increases abilities of solubilizing lipophilic therapeutic agents and cholesterol accounting for its use in the treatment of liver diseases and cholesterol gall bladder stones.
Model maidenhair tree (Ginkgo bilobae) leaf extracts were created basing on medium of diversified polarity (ԐM). Chromatographic analysis was performed with the HPLC method, with the so-called dry residue remaining after evaporating the dissolving agent from saturated aqueous solutions and from 0.1 mol HCl. Viscosity measure and surface activity estimations were conducted on phase boundary. Then, basic values of viscosity ([h], Mh ) and hydrodynamic values (Ro, Robs., Ω) were calculated. Moreover, reference quercetin and rutin (rutoside) were used to mark the conversion contents of flavonoids in produced extracts with the UV method.
Using the general Hildebrand-Scatchard-Fedors theory of solubility, the mole fraction (x2) of solubility of phytochemicals contained in the dry green tea leaves was calculated which determines the profile of pharmacological activity.The applicative purpose of the study was to estimate the actual solubility of phytochemicals – S|real.| [mol/dm3] in water and in water-ethanol solutions of diversified polarity (εM) for their selective extraction and optimal formulation of oral solid dosage form.The basic physico-chemical and structural quantities of phytochemicals and corresponding mathematical equations of general Hildebrand-Scatchard-Fedors theory of solubility were used to calculate the actual solubility – S|real.| and the level of hydrophilic-lipophilic balance (HLB).The calculated actual solubility values – S|real.| [mol/dm3] collated with correlation equations enabled the assessment of phytochemical capability for the process of mass exchange on phase boundary. Correlation equations for the dependence log P = f (– log S|real.|) point to the structural preferences of phytochemicals in the kinetics of the mass exchange (diffusion) through the natural phase boundary.Calculations and correlations between the values characterizing the actual solubility – S|real.|, media polarity (water, ethanol and their solutions) and the partition coefficient (log P) including the level of hydrophilic-lipophilic balance (HLB) show that basing on thermodynamic components of the general Hildebrand-Scatchard-Fedors theory of solubility, the diffusion profile of phytochemicals contained in the green tea extract (Ext. Camellia sinensis L. aqu. siccum) through the biological phase boundary as well as optimal choice of the extraction medium for selective extraction of the class of phytochemicals can be estimated.
Introduction: Dietary supplements are a good way to supplement the deficiency of certain micronutrients and organic components (therapeutic agents) in human body. They are most often available in concentrated form as tablets, capsules, powder or liquid. Objective: To investigate morphological parameters and the pharmaceutical availability of coated tablets – dietary supplements – that contain selected pharmacopeial titrated dry plant extracts. Methods: Testing of the effective time of the tablet surface erosion was performed in model acceptor fluids using pharmacopeial methods in static (Erweka apparatus) and dynamic (unlimited diffusion method) conditions. Furthermore, morphological parameters of tablets (the original shape of an ellipse) as well as their hardness were determined. Results: The effective erosion time was determined by conductometric method using carboxymethylcellulose sodium salt (NaCMC) contained in the tablet. The content of gum arabic and NaCMC in the tablet testifies that the granulate was produced using the “wet granulation” technique which resulted in high hardness of original, esthetic, elliptical tablets and in prolonged disintegration time (erosion). Conclusions: The used excipients: gum arabic and NaCMC for the production of the tested tablets containing selected dry plant extracts result in their high hardness. The tested dietary supplements are characterized by esthetic design, original shape, and prolonged disintegration time which affects the pharmaceutical availability.
Introduction: Common ivy (Hedera helix) is a plant used successfully in the treatment of various ailments. This is possible owing to the unique set of substances contained in it such as large amount of saponins, flavonoids, phenolic acids and phytosterols as well as polyacetylenes and coumarins. All these substances have been used in the production of cosmetic and medicinal preparations. Clinical trials on the efficacy and safety of dry ivy leaf extract have shown its high efficacy, comparable to synthetic medications, and better tolerance of herbal drugs. Objective: Investigations were performed on model ivy leaf (Hedera helix) extracts which were created using a medium of diversified polarity (ԐM). Measurements of viscosity and surface activity on phase boundary were performed. During preformulation studies attention was drawn to the possibility of micellar solubilization of cholesterol and selected structures of nonsteroidal anti-inflammatory drugs (NSAIDs) – ketoprofen. Methods: Viscosity measurements of Extractum Hederae helicis e folium aqueous solutions and in 0.1 mol HCl were performed according to the Polish Standard with Ubbelohde dilution viscometer. The surface tension of aqueous solutions – Δγ25 of Hederae helicis e folium extracts was determined according to the Polish Standard with stalagmometric method . Critical micellar concentration (cmc) was calculated. This enabled to evaluate the dependence ΔG0 =2.303 RT× log cmc of the thermodynamic potential of micelle formation (ΔG0 ). Results: It has been confirmed in the conducted comparative studies that aqueous solutions of Extr. Hederae helicis e folium created with maltodextrin as well as with SiO2 – maltodextrin result in micellar solubilization. The increase of granulometric size of cholesterol particle to Ø 1.60 mm decreased the amount of solubilized cholesterol but solubility preferences of the extracts were maintained. Conclusions: Model extracts produced from Hederae helicis e folium with diversified polarity of the extraction medium (water – ethanol) are characterized by appropriate solubility of the components which results not only from the presence of chlorophyll and its derivatives in the extract but also from the technique used for spray drying of the extract.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.