|
|
Sublingual drug delivery. 5
Čižinská, Lucie ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
Thesis brings detailed information about sumatriptan succinate, its therapeutic use and dosage forms. In particular, it notes its sublingual administration. Then it provides a summary description of migraine as a pathophysiological unit. The experimental part is focused on the evaluation of in vitro transmucosal permeation of sumatriptan through porcine sublingual membrane. In the first set of experiments sumatriptan succinate was used in three aqueous vehicle in the second part as nanofibre or cast polymer membranes. Acceptor phase was always a phosphate buffer pH 7.4. Determination of sumatriptan permeated was performed by HPLC. For a 3% sumatriptan phosphate buffer pH 7.4 solution and citrate buffer pH 3.4 were pertinent values of fluxes J about 50 [µg/cm2 .h-1 ], about 40 [µg/cm2 .h-1 ], respectively. Very low permeation was found at 1% solution sumatriptan in artificial salivary fluid. The evaluation of sumatriptan fluxes in transmucosal permeation from polymeric membranes brought important results. Very low fluxes provided the cast of polyacrylic acid (PAA) membranes containing 10% of sumatriptan: J = 0.29 ± 0.07 [µg/cm2.h-1]. Surprisingly high values were measured from polyvinylalcohol (PVA) cast membrane containing 10% of sumatriptan J = 6.5 [µg/cm2 .h-1 ] and from the nanofiber PVA...
|
|
|
Effect of Lipophilicity of Substrates and Surfactants on the Efficiency of Micellar Hydrolysis of p-N-nitrofenylalkanoates with Alkylpyridinium Bromides
Běhávková, Vendula ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
Rigorosum Thesis 2010, Vendula Běhávková Abstract The subject of this work was to verify if a homologous series of N-alkylpyridinium substances and p-nitrophenylcarbonates possess the reciprocal influence of the length of alkyl chains on the rate of hydrolytic reaction. In a series of N-alkylpyridinium substances was tested pyridinium bromide with alkyl chain lengths of C10, 12, 14, 16 and C18. These surfactants were tested with p-nitrophenyl acetate, -butyrate, -caprylate, -caprate, -laurate, -myristate, -palmitate and-stearate. The highest values throughout the group results were achieved through a combination of p-nitrophenyl-caprate and octadecylpyridinium bromide. 5x10-3 M concentration of surfactant was able to accelerate the decomposition of p-nitrophenyl-caprate 120 times and almost reached the rate constant 0.0878 sec-1 , which corresponds to the half-life is approximately 8 seconds. octadecylpyridiniumbromide and hexadecylpyridinium bromide were proved as successful micellar catalysts. The best hydrolysable substrates were medium-length alkylated.
|
|
|
Nanofiber membranes as carriers of drugs 6.
Bidmonová, Hana ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
Rigorous thesis Nanofiber membranes as carriers of drugs 6. Mgr. Hana Bidmonová ABSTRACT Thesis deals with the evaluation of absorption and the release properties of the nanofibre membranes that were prepared using electrospinning of chitosan solution with the contents of 5 % of a drug and covered with polyurethane layer. Thesis brings a survey about the use of nanofibre membranes in pharmacy and medicine, especially their characteristics and application at drug delivery and distribution and in tissue engineering. The ability of three different membranes to accept and release caffeine as a model drug from their structure was investigated. The caffeine was incorporated into the membranes in company Elmarco, Liberec, or it was impregnated in the membranes using absorption from solutions containing drug. A hypothesis concerned with ability of membranes to accept a part of caffeine by another mechanism than an amount incorporated before electrospinning was confirmed. All of three membranes were immersed in media containing caffeine and they adsorbed the drug in quantity dependent on the sort of liquid medium. At the use of the chloroform dispersions of caffeine, membranes adsorbed more then a mass of membranes themselves. In the set of release experiments of membranes the released amount of caffeine...
|
|
|
Application limits of sublingual drug administration. 1
Turnerová, Lenka ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
The theoretical part of thesis provides basic information about the sublingually administered drugs, describes the primary facts of the medicated membranes for oral systemic administration and about dextrans as the pharmaceutical substances. The experiment focuses on transmucosal in vitro evaluation of permeation of the dextrans of three different molecular weights from aqueous environment throughout sublingual membrane. The measurements of fluxes of caffeine as a marker at the opening period of permeation experiments were performed. An acceptor phase was always the phosphate buffer, pH 7.4. Determination of caffeine was performed by HPLC, the dextrans were determined spectrofluorimetrically. The average flux of caffeine is J = 1370 µg/cm2 .h-1 , SEM = 100,8 (n = 17). The proof of the transmembrane passage of all the mentioned fluorescent-labelled dextrans was given. Surprisingly, the lower permeation rates of dextran 4000 (J = 28,1 µg/cm2 .h-1 ; SEM = 21,4) comparing with dextran 20 000 (J = 42,0 µg/cm2 .h-1 ; SEM = 11,8) were found.
|
|
|
Properties and Influencing of Skin by Rejuvenation Methods. 1. Skin Lipids, Friction and Texture
Kobrlová, Petra ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
The work summarizes information about the basic functions of the skin, its structure, aging and rejuvenation cosmetological methods. An overview of findings from the instrumental treatment of the skin using Intensive Pulse Light (IPL) and fractional CO2 laser and a short survey of objectification cosmetic effects using instruments for sebumetry, frictometry and visiometric texture determination. The experiment is focused on the evaluation of effects of cosmetics creams Liftaktiv CxP Vichy and Vichy Neovadiol Gf, and the use of IPL and fractional CO2 laser rejuvenation methods in relation to selected physical properties of the skin, specifically the content of skin lipids, skin friction and skin texture. 9 women of three age categories were chosen for the experiment. Visia Imaging System (Canfield Imaging System) and CK Electronic Analyser (Courage-Khazaka) were used for evaluation of qualitative changes of the skin. Results were obtained through sensory tests with expert control and instrumental measurements with expert evaluation (Colipa 2008) of the observed data in context with other information about clients. A qualified assessment of impact of the random and systematic effects was given. An illustrative statistical evaluation of skin friction as the one selected variables helped to formulate...
|
|
| |
|
|
Study of dispersity of nanoemulsive drug carriers
Hájková, Hana ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
SUMMERY Theoretical part of this work is focused on explanation of such terms like nanoparticules and nanoemulsions and their usage within peroral and topical administration. Next part explains the merit of zeta potential and DLVO theory, which influence the stability of the elements. Off course, also the principle of the measuring of viscosity is mentioned, because viscosity is taken into consideration in case of measuring of the element dispersion. The experimental part is focused on determination of the partije size by photon correlation spectroscopy by temperature of 25řC and 37řC. The measurement was taken in chronological succession to estimate the stability of dispersion system. It was also measured electrokinetic parameter - zeta potential, which plays a fundamental role by keeping the stability of nanoemulsions. It was proved, that the size of the elements gets settled after approx. 1 week, further changes are not so striking anymore, not even by the increase of temperature to 37řC. Since creating the emulsion (approx. 1 week), the major share of the size of particles (about 60-95%) was ranging between 120-175 nm. As well zeta potencial remains in stable range (+2 mV - -0,6 mV) by the increase of temperature to 37řC and adding of three pH highs of buffers. From the gained results we can draw...
|
|
|
Nanofiber membranes as carriers of drugs 1. Chitosan, polyamide 6, polyurethane.
Beneš, Michal ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
9. Abstract The theoretical part deals, in the introduction, with the questions of the transdermal administration of medicines and also with the current overview of the transdermal preparations registered by the FDA Agency (U.S. Food and Drug Administration). The basic principles of the non-woven fabric production technology focused on the electrospinning method, which is used in the production of nanofiber membranes and evaluated further in the experiment, are described. The next part is dedicated to the characteristics and production of polymers which compose the tested membranes. Some physical tests which were used for the continued characterization of the nanofiber membranes are shown. The first chapter of the experimental part gives the results of the three physical and technical characteristics of the nanofiber membranes produced by electrospinning, from chitosan, polyamide 6 and polyurethane. A piece of the samples from these polymeric non-woven nanomembranes was radiosterilized. From the tensile strength point of view the nanofiber membrane made of polyurethane fibres was the most stable. The radiation sterilization process caused the lessening of the strength of the nanomembrane made of chitosan, of the other two membranes the sterilization process had no significant influence. The membranes made...
|
|
|
Cleaning Validation Procedures in Manufacturing of Liquid Dosage Forms
Koníková, Veronika ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
The thesis preamble introduces validations of analytical methods, as an important process during pharmaceutical development and quality control in pharmaceutical manufacturing. Method validation has essential influence on pharmacoeconomics and greatly shortens the time of placing the medicament to the market. The IMS principle greatly shortens analysis time, thus ensuring economic and innovation growth for pharmaceutical companies. Experimental part of this thesis was performed on the device IONSCAN - LS Smiths- Detection, USA in the branch of the Teva company in Opava, which introduces IMS to analytical procedures validation for cleaning validation in pharmaceutical manufacturing. For measuring, the Naphazolini nitras standard was used and the Teflon dry method was applied. During the method development itself, in which I participated, the method usability range was found in the interval of mass concentrations from 0,06 - 0,80 mg / ml. The detection limit at the level of 0.02 ppm and the quantification limit at the level of 0.08 ppm were determined and linearity was verified. In the second part, I validated the analytical method for cleaning process validation. Sampling was performed by means of polyurethane swabs "Large Swab" from a metal plate of surface size 5 x 5 cm2. From this equipment, a...
|
|
|
Nanofiber Membranes as Drug Carriers 5.
Beneš, Michal ; Doležal, Pavel (advisor) ; Vachek, Josef (referee)
M. Beneš Abstract The theoretical part of this work deals with chitosan polymer and its derivates. A polymer molecule is described in more detail, its solubility and chemical modifications are described separately. In the next part biocompatibility and biodegradability of chitosan are dealt with. Parameters of the electrospinning of chitosan end this chapter. The experimental part is first dedicated to the determination of aquosity in the samples of 3 different nanofiber membranes and to their gravimetric changes by keeping in the desiccator. The samples of membranes absorb water at the most up to 1,5% (m/m) and there is not a big difference among them. The second part quantifies changes in the composition of the saturated excipients which were used for the impregnation of the samples of nanomembranes. The highest amount of caffeine was absorbed by the membrane 3, namely in case of both saturating media. The evaluation of the amount of caffeine which the tested membranes are able to release from their surface in vitro follows. In case of the saturation of membranes by the aqueous solution of caffeine and by the caffeine suspension is the maximum of the subsequent liberation into the acceptor phase reached from the 120th minute. In case of the ethanolic and chloroform saturated solution is the maximal...
|
guest ::
RSS feed.