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Posted by Chemlink in Pharmaceutical Products | 0 comments

Used extensively as an excipient for sustained-release pellets, sugar spheres and their characteristics open a world of possibilities.

Pharm-a-spheres 3D graphic

A multiparticle, solid form of medication, these excipients are near-spherical with diameters that range between 100 and 2000 µm. The hard gelatine capsules provide a method of oral medication, which makes it possible to put powders and granules in a patient-friendly form.

Allowing the combination of partial quantities that differ in appearance with each other (or have differing release behaviours), sugar spheres allow for optimum mixing and flow behaviour for pharmaceuticals. As the pharmaceutical industry has progressed, finding a sustained release coating that allows for the release of active substances at different points in time has become crucial. With sugar spheres offering a suitable pellet solution for numerous requirements, it’s no surprise that they are deemed technologically astute.


Pelletization of active substances

There are numerous procedures for pelletization of active substances; sugar spheres and pelletization that is included in the active substance itself. There are numerous applications for both methods of pellitization, so it is difficult to gauge preference for one method over another. However, as each method offers its pros and cons, pharmaceutical formulators should be aware of the differences to make the best choice for their product.

We will outline the main factors to consider below:

  • The use of sugar spheres allows producers to outsource pelletization to specialists to create an excipient of uniformed size.
  • The shaping process involved in pelletization can cause stability issues.
  • Pelletization and classification produces fractions. When recycled these can often cause homogeneity and traceability issues.
  • Pellets produced by direct pelletization often show moderate mechanical stability.


What do sugar spheres contain and what are their properties?

Sugar spheres characteristically consist of sucrose and corn starch and are deemed pharmacologically indifferent. Due to the presence of corn starch, the sugar spheres also contain water. If there is not surplus water from the production process, this should not interfere with active substances susceptible to hydrolysis. Any attempt to remove this water from the sugar spheres would result in a difficult drying procedure, allowing the sugar spheres to become hygroscopic and absorb moisture present in the air.


The flowability of sugar spheres are assessed using the EP method of the, which is identical to international standards. Thanks to the ideal spherical form of the sugar sphere paired with its smooth surface, the flowability is extremely high. Top quality sugar spheres show low compressibility, and consequently cause few problems in handling and dosing stages.

Particle size

A vital prerequisite for uniform application of active substances lies in particle size. The particle size is defined according to the international sieve series, and usually the specification defines an upper and lower limit within which at least 90% of the particles must lie. For coinciding results to be obtained, there must be precise calibration and matching of the relevant procedures.

Mechanical stability

Further to the above, robustness against mechanical stress is crucial for further processing of sugar spheres. Requiring adequate mechanical stability to withstand loads during coating and exposure to solvents, sugar spheres must first be deemed stable. An effective method for recognising the differences in mechanical properties between pellets or batches is the Born Friabimat. Here, load is created by shaking the pellets in a gall vessel, whereby the first pellets in every cycle impact on the glass lid or surface. This is then followed by friction or impact between the pellets.


To calculate the coating procedure and release kinetics, the surface properties should be known. In sugar spheres, the roundness of individual particles is very high, and their layered structure leads to a low interstitial surface of sucrose crystals with low porosity.

Thanks to their technological properties, sugar spheres are key players in pellet medications. Safe from manipulation, offering differing sustained release rates and available in a divisible form, it’s no surprise that sugar spheres are often considered preferable. Having proven their worth when compared to alternatives, sugar spheres are expected to remain an important excipient for future medications.


10 reasons to choose pharm-a-spheresTM

  1. Due to their special manufacturing process that ensures high mechanical stability, no attrition and low friability, pharm-a-spheresTM offer an important pro that can be quantified upon request.
  2. Because of their high degree of sphericity, pharm-a-spheresTM have a non-porous, smooth surface. Crucial for a precise layering with API and reproducible release of the final pellet, pharm-a-spheresTM are ahead of the game.
  3. Pharm-a-spheresTM uses high-quality excipients and thermal process steps which ensures outstanding microbiological quality.
  4. Consisting of all-natural ingredients such as sucrose, corn starch and liquid glucose, pharm-a-spheresTM are easily digestible and biodegradable.
  5. As particle size can influence the coating process, pharm-a-spheresTM offers sugar spheres with a tailor-made and reproducible particle size distribution.
  6. Conforming to the pharmacopoeial monographs for sugar spheres worldwide, pharm-a-spheresTM are easily registered for any regulatory drug applications.
  7. Active ingredients are not involved in the forming process, so you can minimize the loss of precious API, save thermal and chemical deterioration and start with a defined surface area for reproducible coating.
  8. As pharm-a-spheresTM are chemically indifferent and yield no incompatibilies, there is no need to use spheres of any other composition.
  9. Not only are pharm-a-spheresTM competitively priced, but they are accurate regarding delivery times.
  10. Often, there is no substitute for experience, and pharm-a-spheresTM sugar spheres have had more than 40 years of manufacturing and testing. With a large in-house laboratory that allows for a fast release process and reliable results, our technological expertise is second-to-none.

pharm-a-spheres product details

Learn more about Pharm-a-spheres by downloading their presentation here. Should you require further information or samples, please reach out to Shilpa Mistry, Head of Pharma for the UK & Ireland who will gladly assist you.


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