Lubrication of Direct-Compressible Blends with Magnesium Stearate Monohydrate and Dihydrate - Pharmaceutical Technology

Latest Issue
PharmTech

Latest Issue
PharmTech Europe

Lubrication of Direct-Compressible Blends with Magnesium Stearate Monohydrate and Dihydrate
The influence of magnesium stearate (MgSt) on powder lubrication and finished solid-dose properties presents big challenges to drug manufacturers.


Pharmaceutical Technology


Results and discussion


Figure 2
Solid-state characterization of MgSt hydrates. Isolation of the dihydrate and monohydrate forms by using the vegetable source of MgSt was successfully conducted by the Mallinckrodt team (10). The results of the solid-state characterization showed that on the basis of particle and molecular characterization, substantive evidence exists to support differences in the nature and behavior of the two hydrates (11). Lubrication efficacy of MgSt, vegetable or animal source, has been widely associated with its physicochemical properties such as crystalline state, crystal shape, particle size, particle-size distribution, and particle morphology with a given fatty acid composition consisting of stearic and palmitic acids and fatty acid ratio (9).


Table III: MgSt pseudopolymorph particle size and percent water.
Powder X-ray diffraction. Figure 1 shows the results of the powder X-ray diffraction conducted on the MgSt hydrates.


Figure 3
Scanning electron microscope. Figure 2 shows the results of the characterization conducted on the MgSt hydrates using scanning electron microscopy at a magnification of 2500.


Figure 4
Particle size, percent water, and concentration of neat MgSt-M and MgSt-D. Results of particle size and free and bound-moisture analysis for the MgSt hydrates are shown in Table III. The neat dihydrate had a concentration of 95.4%, and the neat monohydrate had a concentration of 92.0%. The results also indicate that the nominal mean particle size of the monohydrate is 10.6 μm, and the dihydrate has a nominal mean particle size of 14.3 μm. In addition, percent bound moisture was 2.8% for MgSt-M and 5.6% for MgSt-D. Although the percent of free water was generally low, MgSt-M had 0.6%, and little or no free water was found in MgSt-D.


Figure 5
Differential scanning calorimetry, thermogravimetry, and NIR spectroscopy. The profiles depicted in Figures 3a–c show the results of the DSC, thermogravimetry, and NIR reflectance for the MgSt hydrates. These profiles depict the differences between the hydrates of MgSt. The NIR spectra were provided by Kaufman (11).


ADVERTISEMENT

blog comments powered by Disqus
LCGC E-mail Newsletters

Subscribe: Click to learn more about the newsletter
| Weekly
| Monthly
|Monthly
| Weekly

Survey
FDASIA was signed into law two years ago. Where has the most progress been made in implementation?
Reducing drug shortages
Breakthrough designations
Protecting the supply chain
Expedited reviews of drug submissions
More stakeholder involvement
Reducing drug shortages
35%
Breakthrough designations
12%
Protecting the supply chain
35%
Expedited reviews of drug submissions
12%
More stakeholder involvement
6%
View Results
Jim Miller Outsourcing Outlook Jim Miller Health Systems Raise the Bar on Reimbursing New Drugs
Cynthia Challener, PhD Ingredients Insider Cynthia ChallenerThe Mainstreaming of Continuous Flow API Synthesis
Jill Wechsler Regulatory Watch Jill Wechsler Industry Seeks Clearer Standards for Track and Trace
Siegfried Schmitt Ask the Expert Siegfried SchmittData Integrity
NIH Translational Research Partnership Yields Promising Therapy
Clusters set to benefit from improved funding climate but IP rights are even more critical
Supplier Audit Program Marks Progress
FDA, Drug Companies Struggle with Compassionate Use Requests
USP Faces New Challenges
Source: Pharmaceutical Technology,
Click here