Drug Delivery

Drug Delivery

  • Giulia Fulias added an answer:
    13
    Can we find entrapment efficiency of nanoparticles without washing and centrifugation by direct method by simply lyophilizing the whole material ?

    Need urgent reply. 

    Giulia Fulias

    Its ok sir.

  • Titus Sobisch added an answer:
    8
    Is it possible to use water or buffer solution as solvent for drug loading in mesoporous silica of any type?

    Provide references if possible.

    Titus Sobisch

    More simpler case for drug loading is to use solvents easy to evaporate. For drug loading you wish that drug redissolves in biological fluid. For using water you would need to find a condition to precipitate onto the surface, which is different from condition in biological fluid with suitable solubility. However, even when you find a suitable condition precipitation likely will cover surface unevenly. 

  • Giulia Fulias added an answer:
    16
    Hi, is it right to sonicate the formulation at 70 % for 4 minutes to form nanoparticles or not?

    Hi,
    I am preparing nanoparticles by w/o/w double emulsion method.Firstly I am sonicating w/o emulsion at 70 % amplitude for 2 minutes by using sonics vibracell ultrasonic processor 500 W, 20 kHz and then again sonicating the w/o/w emulsion for 2 minutes at 70 % amplitude using sonics vibracell ultrasonic processor 500 W, 20 kHz. Is it right? 

    Giulia Fulias

    Good luck.Total time for sonication was 2 minutes for your formulation?

  • Giulia Fulias added an answer:
    20
    Hi, what to do if the supernatant of nanoparticles has high absorbance than that of standard solution?

    Prompt response will be appriciated.

    Giulia Fulias

    Titus, there was just minor difference of readings between blank and formulation containing drug.

  • Ali A R Aldallal added an answer:
    4
    What are the side effects associated with transdermal microneedles for drug delivery?

    Microneedles are getting popular for delivery  of drugs, vaccines and growth factors. it is cheap and painless. It is being increasingly used by Cosmetic Physicians to deliver Vit C to stimulate extracellular matrix proteins (collagen) in the skin. 

    Ali A R Aldallal

    Transdermal drug delivery
    Mark R. Prausnitz1 and Robert Langer2
    Abstract
    Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability of iontophoresis to control delivery rates in real time provides added functionality. Third-generation delivery systems target their effects to skin’s barrier layer of stratum corneum using microneedles, thermal ablation, microdermabrasion, electroporation and cavitational ultrasound. Microneedles and thermal ablation are currently progressing through clinical trials for delivery of macromolecules and vaccines, such as insulin, parathyroid hormone and influenza vaccine. Using these novel second- and third-generation enhancement strategies, transdermal delivery is poised to significantly increase impact on medicine.

  • Dignesh Khunt added an answer:
    1
    What is the maximum concentration of phospholipid which can be used for intramuscular/parenteral drug delivery of liposome?

    What is the maximum concentration of phospholipid which can be used for intramuscular/parenteral drug delivery of liposome? Please give list of positively charged, neutral charged and negatively charged phospholipids..

  • Eduard Fidler added an answer:
    3
    How many antibodies per Nanoparticle would result in effective targeting of an antigen?

    Hi All,

    I am working on conjugating Anti-EGFR antibodies to the surface of PLGA-PEG-maleimide nanoparticles to target tumor cells over-expressing EGFR.

    My question is approximately what ratio of mAB to nanoparticle should I aim for in order to achieve good targeting. Does anyone have experience here they would like to share?

    All help is greatly appreciated!

    EF

    Eduard Fidler

    Thank you for the help gentlemen! Best of luck in your research!

    EF

  • Giulia Fulias added an answer:
    7
    Hi, how to find concentration of the drug in the supernatant to find entrapment efficiency of nanoparticles?

    After collecting supernatant which pore size filter is used to filter the supernatant? After filtration do we take its UV absorbance or to do anything in between? After taking its absorbance what to do next?

    Giulia Fulias

    Yeah its helpful. Thanks everybody.

  • Patrick Simms added an answer:
    3
    What are the current technologies regarding pH-sensitive materials for drug administration?

    Could somebody with expertise in methods of drug administration point me in the right direction? I'm working with a new polymer which can be customized to degrade in different pH environments along the GI tract, and I was wondering about the challenges faced/applications of current technologies. I can't find much information on pH-sensitive hard shell capsule materials other than hypromellose. Is this a beneficial property? Can it be used for site-specific drug targeting etc?

    Any feedback is much appreciated!

    Patrick Simms

    Dear Eaton,

    I suggest looking at this from the point of view of pathologies of diseases of the gastrointestinal tract.
    For example pancreatitis is treated with very large doses on enzymes because the enzymes are sensitive to pH of the stomach and easily digested. Controlling drug release relative to local pH conditions may allow for discrete drug administration as the capsule travels through the gut and this may allow significantly smaller doses. Of course this example assumes absorption of enzymes would occur after the stomach etc...
    Best, Patrick.

  • Shahab Bazri added an answer:
    10
    What is a 25 wt. % solution of tetramethylammonium hydroxide in methanol mean?
    What does wt% mean?
    Shahab Bazri

    Percent by mass (weight): is the percentage of the ratio of one component mass to the total mass of the solution. (wt. %: wt% signifies weight or mass percentage)


    “mass % A (wt. % A) = mass(A) ÷ (mass(A) + mass(B) + mass(C) + ...) x 100”

  • Brooks Witzke added an answer:
    2
    Can Cycloastragenol Powder be taken through the Buccal Delivery Method (sublingual)?

    It has become very common practice with supplements to administer some through the Buccal delivery method (sublingually). In fact, Resveratrol is best absorbed when taken under the tongue and when bypassed the gastrointestinal tract totally.

    My question, can you put cycloastragenol powder underneath the tongue for better absorption into the bloodstream and better activation of telomerase ? Is Cycloastragenol one of the supplements that can be absorbed through the lining of the mouth? Thank you, Brooks

    Brooks Witzke

    Thank you 

  • Ramanjireddy Tatiparthi added an answer:
    1
    Has anyone experimented with different drug delivery methods for THC?

    I'm curious about different delivery methods for chronic THC exposure in adolescent rats (3 weeks). Typically, intraperitoneal injections of THC are used, but I'm wondering if there is an easier/less stressful method.

    Some ideas I'm considering include:

    1. Osmotic minipump implants. This might be the simplest method.

    2. Food delivery. Mixing THC with a palatable food like strawberry/chocolate milkshake, or jello, with appropriate pre-exposure of drug and vehicle to avoid conditioned taste aversion. I know jello has been used with alcohol studies.

    3. Catheter implantation. Daily intravenous delivery of THC would allow for very precise control of drug delivery according to daily body weight. 

    I'd be very curious to hear of any ideas others have tried.

    Thank you!

    Ramanjireddy Tatiparthi

    Mr.Andrew, if we given along with food supplements, the oral bio availability has only 30%, along with alcohols improves the bio availability of THC. if it through implants, we need minor surgery it is also additional impact on health, making  of an implant makes much costlier delivery and it also a controlled product

  • Barid Baran Lahiri added an answer:
    5
    Does anyone have experience with hyperthermia experiments?
    I am working on Iron Oxide NPs apply on Hyperthermia and Chemotherapy treatments.I read on some papers about the Hyperthermia Equipments. It is combined from the different machine such as : sensor, generator, etc.
    Barid Baran Lahiri

    Hi Carl,

                This is in continuation to our earlier discussion. I am getting a field of 0.82 kA/m only at 2.5 kW power transfer. I have copper coils (water cooled), diameter is 50 cm and six turn. The current increases if we put a solid metal inside the coil. Otherwise for magnetic nanofluids we are not being able to push the current. Will be waiting for your response as we find the problem very fascinating. Will also be happy to provide further details if required. Nevertheless, I am not an electrical/electronics engineer. So pardon my limited technical knowhow.  Thanks.

  • Sajal Kumar Jha added an answer:
    2
    Hi, at what temperature and pressure Eudragit nanoparticles should be lyophilized?

    Looking for answer.

    Sajal Kumar Jha

    1 mbar pressure and −110°C temperature

  • Raja Rajeswari Kamisetti added an answer:
    4
    Do hydrogels containing Methacrylic acid swell and release drug moeity at pH 6.8?

    I want to know about release of hydrogel microparticles (MAA) at pH 6.8?

    Raja Rajeswari Kamisetti

    Ofcourse they swell. But the swelling rate depends on the ph depending on the type of monomer. And i too follow the previous answers.

  • Parikshit Banerjee added an answer:
    2
    Can i use Hyaluronic acid (HA) as a monomer in superporous hydrogel for Gastroretentive drug delivery for eradication of Helicobacter Pylori?

    Hydrogels having ability to create effective pore size larger than 10μm are known as Super-porous Hydrogel mainly used as gastroretentive drug delivery platform.

    Parikshit Banerjee

    I mean is it possible to use HA as co-polymer to obtain an interpenetrating polymer network superporous hydrogel?

  • Sujoy Sarkar added an answer:
    3
    How can I decide which molecular weight (1000, 5000, 20000kDa) PEG to use in Graphene Oxide Drug Delivery?

    I am trying to conjugate PEG on to Graphene Oxide via EDC coupling method. However, I am still not sure which molecular weight PEG I should use, and what kind of difference it can make. What are some tips on choosing the size of PEG and the reason to do so.

    Thank you for the advice.

    Sujoy Sarkar

    Check this article, close to what are you looking for

    http://arxiv.org/ftp/arxiv/papers/0808/0808.3396.pdf

  • Philip Jung added an answer:
    5
    Is there anyone who can analyze with confocal microscopy my compound at 980 nm excitation?

    Drug delivery, Cell imaging,  Is there anyone who can analyse confocal microscopy of my compound at 980 nm excitation?

    Philip Jung

    Probably, you need to use multi (or two) photon laser scanning microscopy at 980nm.  980/2 = 490nm, so you can you commercially available dyes.

  • Hamidreza Maroof added an answer:
    4
    Does anyone know how to label the PEGylated liposome with TSH antibody?

    conjugating thyroid stimulating hormone (TSH) antibody with liposome for having more efficient drug delivery in the murine model.

    more information will be provided upon request 

    King Regards

    Hamidreza Maroof

    thanks, Gregory,

    It seems working now

  • Jagadevappa S Patil added an answer:
    4
    Should I ignore an initial burst for drug release while examining the appropriate drug release model?

    Just between zero, first order, Huguchi and Peppas models.

    Jagadevappa S Patil
    Dear Prabhanjan,

    It depends on situation and your requirements. Some time initial burst release may be considered important.
  • Shuaib Khan added an answer:
    2
    Can anyone suggest a carrier for beta-sitosterol that can be used sublingual?

    Trying to develop a sub-lingual delivery system for free sterols without converting them to esters.

    Shuaib Khan

    Dear Mathhew,

    HPMC will be fine,

    HPMC is a very good and different grades viz Methocel E3, Methocel E5, Methocel E15 Premium LV, etc.are available. Other natural polymers starch and pullulan can also be a choice.

    Regards

    Dr Shuaib

  • Balavigneswaran Karthikeyan added an answer:
    6
    How one should conduct in vitro drug release study when the drug is not soluble in Phosphate buffer?

    I would like to study the docetaxel release from Nanofibers/3D Scaffolds where docetaxel is not soluble in water so which is the preferable medium to conduct in vitro drug release study at pH 7.4. Can someone help me out?

    Balavigneswaran Karthikeyan

    Dear Fitria,

    u meant to say adding tween or anyother surfactant where the drug soluble? I have not tried any such thing. will that work? wont it cause any problem in the release kinetics profile?

  • Rajiu Venkatesan added an answer:
    12
    I need to know zeta potential values in drug delivery?

    What should be the zeta potential values of a drug in drug delivery?

    Rajiu Venkatesan

    There is no angel and demon numbers in zeta potential measurement for drug delivery applications. Conventionally above +30 mV or below -30 mV is represent their colloidal stability of the particles. Further, It indirectly tells us the surface charge of the nanoparticles (caution: it doesn't measure surface charge). You may not able to get above or below 30 mV values for PBS solution and it always show 0 mV. Because, the Zeta potential measurement strongly depends on pH, temperature, counterion concentration, counterion size and counterion valency.    

  • Birger Brodin added an answer:
    2
    In vitro Transcytosis Assay - but no instrument to measure TEER?

    I would like to set up an in vitro assay to evaluate transepithelial transport of drug compounds using transwells with Caco-2 monolayer.

    We do not have a voltohmmeter that is typically used to measure transepithelial resistance (TEER) and is reflective of monolayer integrity.

    Is there a way I can still do the assay without measuring the TEER, and will the results still be valid? Any suggestions / feedback would be greatly appreciated.

    Thank you!

    Birger Brodin

    Dear Phaik

    You may investigate the tightness simply by running parallel experiments where you investigate the permeabilities mannitol (radiolabelled) or sodium flourescein (flourescence detection) and compare values with litterature data, in order to ensure monolayer integrity.

    BR Birger

  • Ram Nath Mishra added an answer:
    1
    Looking to make a carboxamide prodrug?

    I am trying to couple my compound with terminal carboxamide amine to lysine amine. Is there any prodrug for carboxamide so that the Lysine-compound conjugate breaks down to give carboxamide?

    Ram Nath Mishra

    Might help!

    Recent Trends in Targeted Anticancer Prodrug and ...
    www.ncbi.nlm.nih.gov › NCBI › Literature › PubMed Central (PMC)
    by Y Singh - ‎2008 - 
    Prodrug and conjugate design involves the synthesis of inactive drug .... Tegafur is a slow-releasing prodrug of 5-FU, which avoids the rapid breakdown of drug in ...... FUDR to aliphatic carboxylic acid chains to improve drug permeability [134]. ... greatest in the prodrugs with lysine and arginine residues giving IC50 values ..

  • Giulia Fulias added an answer:
    3
    Can we give a suspension of Eudragit nanoparticles by nasal spray?

    If I prepare Eudragit nanoparticles and later convert it to suspension and use it as nasal spray, would it be ok? Remember drug is neither for respiratory tract, nor it has to target brain. I have not seen any article so far in which eudragit alone has been used in the nasal route. 

    Giulia Fulias

    Thank you.

  • Giulia Fulias added an answer:
    4
    Can we give a suspension of Eudragit nanoparticles by nasal spray?

    If I prepare Eudragit nanoparticles and later convert it to suspension and use it as nasal spray, would it be ok? Remember drug is neither for respiratory tract, or it has to target brain. I have not seen any article so far in which eudragit alone has been used in the nasal route. 

    Giulia Fulias

    Thank you.

  • Shuaib Khan added an answer:
    5
    Dose any one know the noval formulations to deliver growth hormone orally?

    Dose any one know the novel formulations to deliver growth hormone orally?

    Shuaib Khan

    at present, liposome, nanocapsules are widely used for delivery of growth hormones and peptides.....only thing you have to keep in mind is the polymers used  for the delivery.

    PVA and PAA are mostly used ..you can search for preparation of nanocapsules OR liposomes using these polymers.....

    Good Luck

  • Mira Kowalska added an answer:
    3
    How do I calculate flux of drug permeation?

    Hello!

    I am investigating permeability of a drug trough silicone membrane. I plotted a permeation profile graph

    x axis: time [h];

    y axis: cumulative amount of drug [ug/cm2] 

    Does anyone know how from this point how do I calculate steady state flux [ug/cm2/h]? 

    Mira Kowalska

    Thank you very much for your both answears! It was very helpful!

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