What differences might be there in the SSNMR spectra of crystalline and amorphous phases of an API?

05 May 2018 0 6K Report

How to characterize amorphous phases of pharmaceuticals with solid state NMR ?

Badges
Science topic

More Mahendra Singh's questions See All

How to calculate the chemical potential of amorphous solids using sorption/desorption data?

Crystalline and amorphous solids have different chemical potentials. May be this is one of the reasons of higher reactivity of amorphous solids.

01 February 2019 3,278 1 View

How to calculate the paired distribution functions of amorphous solid from PXRD DATA (eva file)?

Paired distribution function (PDF) is the characteristic of amorphous solids. How we can calculate this with the PXRD data?

11 December 2018 2,308 3 View

Can anyone would like to share some excellent literature about the calculation of solubility parameters of organic molecules including polymers?

The very first requirement of the mutual solubility of chemical compounds is that the solubility parameters of these chemical species should not differ too much.

11 December 2018 1,567 0 View

What are the factors that determine the stability of amorphous solids?

Amorphous solids are unstable. A number of environmental factors may induce their conversion to their crystalline counterpart. This vanish the solubility advantage of amorphous pharmaceutical...

10 November 2018 7,869 0 View

What is the hydrogen bond acceptor strength of two hydrogen bond acceptor groups present in PVP k30 polymer?

PVP is the frequently used polymer in the solubility improvement of poorly soluble drugs. Structure elucidation revealed that there are two hydrogen bond acceptors (amide carbonyl group and N...

09 October 2018 3,489 0 View

How to characterize the amorphous-amorphous phase separation ?

i would like to know that how we can characterize the amorphous-amorphous (amorphous drug and amorphous polymer) phase separation?

07 August 2018 7,198 0 View

How would i know the required solubility of an API for the development of solid oral dosage form?

I am trying to develop a solid oral dosage for an API. how i would know the optimum solubility for this API?

06 July 2018 9,693 0 View

How to characterize the miscibility of the two polymers in the solution state?

can someone let me know that how to characterize the miscibility of two polymers in the solution state? The miscibility of two polymers in solid state is characterized by the single Tg in DSC...

06 July 2018 5,563 0 View

How to characterize the adsorption of smaller particles on a larger one?

Can someone help me in the characterization of adsorbed smaller particles on bigger particles? i have used only one technique that is scanning electron microscopy to visualize the adsorbed particles.

05 June 2018 9,260 3 View

How to calculate the theoretical amorphous "solubility" of an API?

i am trying to develop a formulation in which API will remain in the amorphous form. I am facing problem with the calculation of theoretical amorphous solubility.

05 June 2018 3,663 0 View

How are iso-frequency contours plotted?

Let's say we have a standard, regular hexagonal honeycomb with a 3-arm primitive unit cell (something like the figure attached; the figure is only representative and not drawn to scale). The...

07 August 2024 1,937 1 View

Why do paired electrons atoms produce no magnetic field lines?

If you think of electrons with spin as bar magnets, you know bar magnets of opposite polarity as long as they're not occupying the same spatial location don't cancel out each other's magnetic...

03 August 2024 3,927 2 View

How to correctly use the UTE and ZTE pulse sequences in Bruker's ParaVision software?

I am using a Bruker 600M solid-state NMR spectrometer with a Micro 2.5 microimaging system. The test sample is a tube of 1M LiCl aqueous solution, and the nucleus detected is 1H. I am trying to...

01 August 2024 9,227 1 View

Mossbauer spectroscopy Co0.6Mn0.4Fe2O4 MNPs?

Following curve related to Co0.6Mn0.4Fe2O4 Magnetic nanoparticles with extra phase a-Fe2O3. I will appreciate to help me to interpretation this spectroscopy, especially the blue line.

31 July 2024 9,140 2 View

IHC profiler in image j software. has anyone used it to quantify nuclear DAB positivity?

Dear researchers. I tried using the IHC PROFILER in image j to quantify nuclear DAB staining. I followed the instructions in the original article by "Varghese F, Bukhari AB, Malhotra R, De A...

29 July 2024 2,229 0 View

What is the solubility of Iron (+3) in Bismuth Oxide?

Dear all: I am modifying Bismuth Tungstate with Hematite (Fe2O3), so I would like to know about how much Iron(+3) can form a solid solution in a Bismuth Oxide matrix. Best wishes Marco

29 July 2024 2,163 1 View

Optimal siRNA Volume for Complexation with Liposomes in a 2.5 mL Solution with 10 mg/mL Lipid Concentration?

How much volume of siRNA can I add to 2.5 mL of liposomes with a total lipid concentration of 10 mg/mL?

27 July 2024 6,920 1 View

What is single absorption ESR spectroscopy ?

In the context of Electron Spin Resonance (ESR) spectroscopy, under what conditions is an absorption spectrum considered to be a single absorption spectrum?

25 July 2024 2,325 1 View

How many events should be counted for the analysis of apoptosis with nuclear staining with Hoechst 33342 whit microscopy ?

Greeting How many events should be counted for the analysis of apoptosis with nuclear staining with Hoechst 33342 whit microscopy ? Are 100 events count sufficient and three repetitions for...

25 July 2024 7,520 0 View

Can any one let me know the PDE value for Tert-Butylamine in order to control in the API?

PDE value for Tert-Butylamine

24 July 2024 1,166 0 View