Drug Release

Drug Release

  • S. Sungthongjeen added an answer:
    Can we crush a sustained release tablet?
    Is it possible for a person to crush a sustained release tablet for fast action?
    S. Sungthongjeen · Naresuan University

    In general, you should not crush sustained release tablet, especially, reservoir type or membrane controlled tablet. If you break the coating membrane, you will get overdose drug because the system will lost controlled release properties.

  • Ramkumar Ponnuraj asked a question:
    How can I plot a kopcha graph and identify A & B?

    Does any one know how to plot Kopcha graph and identify A & B. I could not find any answer for this. Want a quick reply.

    Thanks in advance 

  • A. B. Samui added an answer:
    To study the effect of polymer's degree of crystallinity on the drug release behavior which method is better, DSC or XRD?

    Both DSC and XRD have been used widely to determine the crystallinity of polymers. which one can help me better on investigating the drug release behavior from polymers? Is there any better method rather than these two?

    A. B. Samui · Defence Institute of Advanced Technology

    First thing to do is DSC and next go for XRD. You can study further to link with the application by analysing the nature of crystal by using hot stage optical microscope.

  • Why do functionalized monomers can help solubility and drug release?

    For the synthesis of the pressure sensitive adhesive solution polymerization

    Hi Reza

    Well I can't say if the attached paper and link are good/bad because the subject does not fit with my interest field, please check them.
    With my best regards

  • Yasam Venkata Ramesh added an answer:
    What solvent system should be used for liposomal digestion?

    How much time does it take for drug release?

    I have added methanol for digestion of liposomes. Does the drug release take place immediately or do we need to wait for a few hours for release from the liposome for UV absorbance measurement?

    Yasam Venkata Ramesh · JSS University

    Dear lakshmi,

    triton X-100 is preferable for immediate drug release in most of the cases. drug release also depends on the lipids concentration used.

    regards

  • Sudip Mukherjee added an answer:
    What is the serum concentration we should use for drug release study?

    Fbs can be used for drug release study. But shall we use 100% FBS or 50%?

    Sudip Mukherjee · Indian Institute of Chemical Technology

    Thanks  Mr. George Dakwar for your answer.

  • Ali Akhoondi added an answer:
    Can anyone assist with the investigation of lipophilic compounds release?

    Can someone explain to me how to measure the release of a lipophilic compound to gastric solution while this lipophilic drug can not be dissolved in aqueous? I used Surfactants and ethanol in release media, but did not observed any release.

    Ali Akhoondi · Ferdowsi University Of Mashhad

    thanks Mr Narayanan

  • Mohd Qasim added an answer:
    How can I do a magnetic field-assisted thermo-induced drug release study of magnetic nanocarriers?

    I have some nanocarriers which have drug and superparamagnetic nanoparticles inside them. The nanocarrier is made up of a thermo responsive material.

    After application of an AC magnetic field, the magnetic nanoparticles are supposed to give heat that will cause structural change in the nanocarrier's material, thus drug release.

    How do I check it? Can I use a regular induction heater?

    Mohd Qasim · University of Hyderabad


    Irene Andreu @ thank you very much for such a beautiful explanation.

  • Mohd Qasim added an answer:
    How to release a drug upon alternating magnetic field application?
    I am trying to induce the release of a drug from my formulation (polymer+magnetic nanoparticles+drug) using externally applied alternating magnetic field. At my University we have an induction heater (IHG04AC Induction heater, Across International, US) and I tried to use it applying the following parameters:

    1. Freq = 250 KHz (Maximum)
    2. AC current = 400 A (Maximum)
    3. Duration = 9.9 sec (Heating timer range) + 9.9 sec (Dwelling timer range) + 9.9 sec (Cooling timer range)
    4. Loops = 3-turns coil with internal diameter of 2.5 cm.
    5. Power = 4 KW.

    But unfortunately after 10 min with 19.8 s on (since magnetic field is on only in the heating and dwelling time ranges) and 2 min off nothing was released. Even when I used tubes rather than a dialysis membrane to overcome the diffusion limitation and withdrew a sample and centrifuged it to determine the concentration of drug in the supernatant to compare it with a tube that has not been subjected to alternating magnetic field. The concentration of drug obtained from both samples were the same indicating that the magnetic field did not induce any change.

    The properties of my formulation includes the following:
    1. Ms = 48.6 emu/g
    2. Coercivity = 9.85 G
    3. Remanence = 0.498 emu/g
    4. Concentration in the testing vial = 0.5 mg in 1 ml DI H2O
    5. Size of the Magnetic nanoparticles = 5 nm.

    So I was wondering what could be the reason for the lack of drug release? Is it the duration of magnetic field applied? or Should I increase the concentration of the magnetic nanoparticles? Or could be it be something wrong with the induction heater itself? Am I using the wrong type of induction heater according to its properties to induce drug release from my formulation?

    An advice is highly appreciated if possible to help me in completing this part of my thesis.

    Thanks a lot for your help and consideration.
    Mohd Qasim · University of Hyderabad

    Really a good discussion and full of knowledge.

  • Mohd Qasim added an answer:
    Why wouldn'ts magnetic nanoparticles release heat or drug from polymeric nanoparticles upon the application of a magnetic field (induction generator)?

    Magnetic nanoparticles of size 5 nm

    Frequency applied= 247 kHz

    Magnetic field magnitude applied= 31.5 kA/m

    Temperature of sample detected with an Opsens IR-sensor OTG-A-62 or with an IR pyrometer

    Mohd Qasim · University of Hyderabad

    generally drugs get releases from the polymeric carriers if it it changes carrier phase(transition) at some particular temperature(in this case).. What is the transition temperature of your polymer? I may be that increment in the temperature is too small to cause a phase change in polymeric network.

  • Javier Calles added an answer:
    How do you calculate the cumulative drug release in percentage?

    I have the absorbance data as well as the corresponding concentration values at different interval for drug release study. Please help me to get the percentage of cumulative drug release at different times

    Javier Calles · Universidad de Valladolid

    You must calculate at each time the amount (not the concentration) of drug released to the total medium and add it to the amount of drug that you take of the medium in each sample for each time.

  • Trevor Tilly added an answer:
    How can I find the calibration curve of the loading/release of gentamicin from TiO2 nanotubes?
    I am new to the subject of drug release. I'm trying to study the loading and release of gentamicin from TiO2 nanotubes. The study will be done through UV-VIs. How can I get the calibration curve? Is o-phthaldialdehyde the only agent derived from gentamicin? How must it be prepared? Is the concentration adjusted due to the replacement of the PBS?
    Trevor Tilly · Wright-Patterson Air Force Base

    Dear Javier,

    Please see this article, it may help you.  They use UV-Vis.  Are you using hydrothermally synthesized or anodization synthesized TiO2 NTs?

  • Umut Cagin Ari added an answer:
    What is the best AI time in 14 days CIDR application in sheep?

    I have planned 14 days CIDR application in sheep. I will treat also eCG and PGF2 alfa 2 days prior to withdraw of CIDR. However, I do not exactly sure when I have to carry out Timed Artificial Insemination with fresh semen via intracervical. Normally, eCG and PGF administered on withdraw of CIDR and TAI applied 48 or 56 h after withdraw of CIDR or PRID. Some studies point out 56 hours is best for intracervical artificial insemination. Do you have any experience about 14 days application of CIDR and eCG and PGF 2 days before CIDR withdraw?

    Umut Cagin Ari · Kafkas University

    Hi Ali, Thank you for your answer and paper...

  • Shamit Shrivastava added an answer:
    Why in a drug release experiment using fluorescein does the amount released from polymeric nanoparticles reach more than 100%?

    I am using polymeric nanoparticles entrapping fluorescein and by placing these nanoparticles in a dialysis membrane placed in PBS from which i take samples at different time points. After calculating the amount released and dividing it by the amount entrapped the % Release is always more than 100%. 

    Shamit Shrivastava · Boston University

    In addition to what Adam said, the fluorescence intensity on a surface and in bulk can also be different due to ordering of the dye orientation on a surface which can further enhance quenching. A simplified way forward would be to have different calibration curve and controls for the bulk and nanoparticle measurements.

  • Deon Bezuidenhout added an answer:
    Why I can not detect bFGF using the Peprotech ELISA development kit?

    I am working on the release profile of bFGF (Prospec) from PLLA. The supernatant samples were collected for 50 Days. Release solution composition was 0.2% BSA and 0.1% Sodium Azide in PBS, bFGF loaded PLLA samples were kept at 37C with 150 rpm.  at given time point the samples were centrifuged 5000rpm for 5 minute and supernatant was kept at -80 C.  When i have performed ELISA using HUman FGF-basic ELISA Development KI\it 900-K08  Lot# 1009008 I can not detect the bFGF. If any one has experienced this problem before, or any have better suggestion please let me know what may be wrong in my experiment.

    This ELISA Kit can detect the bFGF (Prospec) as i have checked this.

    Thanks

    Deon Bezuidenhout · University of Cape Town

    The half life of bFGF is reported to be as short as 12h in vitro, so I agree with the previous comments. Also, how did you incorporate the GF into the PLLA? Harsh conditions e.g. use of heat or organic solvents may also denature the growth factor. Regards. Deon.

  • Nolan Wilson added an answer:
    Does anyone have knowledge about Peppas Equation?

    About drug release in peppas Eq, anybody knows how I can find kinetic constant (with units of T^-n) in Mt/M=K*t^n ? I have other terms.

    Thanks

    Nolan Wilson · Tolmar Inc.

    Just a note on the methods of fitting to the Peppas equation.  Mt/M_inf=K*t^n is only applicable in the range of Mt/M_inf < 0.60.  This is an assumption in the empirical derivation of the equation.  The literature is riddled with misapplication of the equation as it is easy to implement but the interpretation usually gets muddled.  Find the original papers if you can as they will give you the best insight into how to apply the equations.

    Edit1:  Below is a publication which outlines the semi-empirical derivation of the Peppas equation as well as demonstrates how to apply it.

  • Differences in drug release from carbopol matrices
    What is the effect on drug release from carbopol matrix tablets using highly soluble and practically insoluble drugs?

    Hi Zargar

    I hope that attached papers are helpful, please check out.

    Best Regards

  • Sudip Mukherjee added an answer:
    Does anyone have a protocol for an in vitro drug release study from gold nanoparticle?

    Protocol for in vitro drug release study on bioactive compound conjugated gold nanoparticles.

    Sudip Mukherjee · Indian Institute of Chemical Technology

    You centrifuge your gold-drug nanoconjugates. The pellet obtained should be incubated with PBS in a time dependent manner. Again you do centrifuge and measure the drug present in the supernatant by HPLC method.

  • Lev Ivanovich Kurlapov added an answer:
    Diffusion membrane: what are the different kinds of membrane we can use for diffusion studies? and which is better?

    I have been using celo-phane membrane for diffusion studies but not getting drug release in a requsite manner..so can i think that  membrane is not upto the level..pls help

    Lev Ivanovich Kurlapov · Kazakh National Technical University

    To studing  diffusion it is necessary use cylindrical tube (1 or 3, 6 ...many.) which have known cross section and length  May be as in attach. article.

  • Zhi-Qiang Zhang added an answer:
    Can anyone offer me some chemical linkers which are thermal-induced cleavage at 45-50 oC please?

    Hi, everybody. I am trying to design a hyperthermia induced drug release nano-system, containing a thermal-sensitive chemical linker which would be cleavage and release conjugated drugs after thermal treatment. It's best that this linker owns -NH2 ending.

    However, i haven't found out an appropreate thermo-induced cleavaged linker between drugs and other polymers. 

    It seems azo linker is a candidate, which would release nirogen gas by cleavage in high temperature. 

    Please reccommand some text books or papers in terms of stimulus-induced cleavage of chemical bond, e.g. cleavage of disulfide linker in high inracellular glutathione (GSH) concentraion

    Thank you every big man

    Zhi-Qiang Zhang · Korea Institute of Science and Technology

    thermo-sensitive polymeric micells are not i am looking for, but thank you a lot all the time.

  • Rakesh Kumar Tekade added an answer:
    In Drug delivery system, How does the drug get released ?

    Suppose if you take a drug carrier like Hollow silica, will be due to hydrophobic attraction.  Same thing in stomach juices, How is get delivered.  What is the property of stomach juices made the drug to  deliver.  For example, in ion exchange, the bulkier and highly charged ions will replace smaller and less charged ions.  Can we say any property is the reason for it.

    It is released on basis of particioning and concentration dependent solubulity of drug. Also polymer barrier leads to sustained release because it impose opposition to its release.

    Some drug delivey sustem like gelatin nanoparticle release of drug takes place de to slow dissolution or biodegradation of polymer.

    In case of delivery system like dendrimer, it is loosening of drug-polymer interaction; that eventually leads to drug release.

    So overall, it dpends on type of drug delivery ststem we are using.

  • How do I extrapolate drug release profile from Rabbit to human?

    How can we  get closer to human data by using animal model?

    Hi tejas

    I hope that following article will help you.

    Best regards

  • Raghdaa Hendy added an answer:
    Is PHB FDA approved for oral dosage form?
    It is safe to use PHB for oral dosage form and what about its drug release behavior or mechanism?
    Raghdaa Hendy · Cairo University

    Thank you Dr. Fakhrul Khan.

    I really appreciate your help

  • Deon Bezuidenhout added an answer:
    Can anyone explain to me how to construct a manual hypoxic system for a cell culture and drug release study?
    I want to use normoxic and hypoxic conditions.
    Deon Bezuidenhout · University of Cape Town

    Hi Zaheer.  You either need a controller to regulate the composition of the gas that goes to your incubator (or a simpler system, like a chamber you can make to fit into your incubator to save on gas and use the temp of the existing incubator), or you need to get the gas company to make you special mixtures cotaining the exact composition you would like to use.  This is not my speciality but have heard of this from a colleague.  Hope this points you in the right direction.  There are companies that sell inserts , e.g. http://www.biospherix.com/cell-culture-equipment/hypoxia-chamber-c-chamber.html but I gather that you want to build your own? Regards. Deon

  • Jose Martinez Calderon added an answer:
    What is the best statistical test for drug release studies?
    I'd like to hear some people's opinions on what is the most appropriate statistical test to perform on data from drug release studies. Specifically, I've been developing nanoparticles that release their drug contents in response to light, and therefore am looking more at the statistical significance at a specific time point(s) (between nanoparticles exposed to light and those kept in the dark) that an overall difference between release profiles. I've been using T-tests (correcting for multiple comparisons) rather than the usual ANOVA, but wanted to hear some additional feedback.
  • Farhad Rikhtegar asked a question:
    Can (bound-free) Paclitaxel pass the endothelial layer through normal junctions and cell lipid membrane?
    To model the drug transfer from a stent coated with paclitaxel, I am very eager to know whether the paclitaxel released from the stent coating inside the lumen can pass the endothelial barrier. I know that LDL passes only through vesicular pathways and leaky junctions as the endothelial layer blocks any solute with radius bigger than 2nm, and it is not soluble in cell membrane. I want to know if paclitaxel behaves similarly. I could not find any explicit value for bound-free paclitaxel size, and pathways.
  • Surendra Agrawal added an answer:
    Drug release experiments - can anyone help?
    I am studying the release kinetics of piperine in PBS using hydrogels, during the study I observed a decrease in absorbance value, I am replacing the medium with the same amount of fresh PBS that I take for sampling.

    Is the decrease in absorbance possible? Will that give me a steady profile of drug release with time?
    Surendra Agrawal · Narsee Monjee Institute of Management Studies
    Rightly pointed earlier by others, first of all you should confirm the media by studying solubility studies. then there is chance of drug degradation and third important factor is piperine has recrystalizing tendency with some solvents.
    Study all those carefully..........
  • Mohammadhasan Hedayati asked a question:
    Is there anybody working with curcumin release from Nanoparticles in a dialysis tube?
    I am studying release profiles in MSN, but pure curcumin does not pass from a dialysis tube (12KD). Any help would be great for me.

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