Sorbitol Coated Granules are pharmaceutical excipient granules consisting of a sorbitol-based core with a defined coating system applied to the granule surface. They are developed for pharmaceutical formulation and processing applications where a coated granulated physical form is required.
Sorbitol, also known as d-glucitol, has the molecular formula C₆H₁₄O₆, molecular weight 182.17, and CAS Number 50-70-4. The current USP-NF monograph defines Sorbitol as containing not less than 91.0% and not more than 100.5% d-sorbitol, calculated on the anhydrous basis.
FCC describes sorbitol as occurring as a white powder, granules, or crystalline masses. It is very soluble in water and is hygroscopic.
The coated granule format adds a defined surface layer around the sorbitol core. Depending on the coating composition and intended application, the coating may modify surface characteristics, moisture interaction, mechanical properties, dissolution behavior, or compatibility with downstream formulation processes.
Sorbitol Coated Granules are granulated pharmaceutical excipient materials in which a sorbitol-containing core is surrounded by a controlled coating layer.
The sorbitol core provides the underlying chemical and physicochemical characteristics, while the coating provides additional functional properties. The final behavior of the material depends on the composition and structure of both the core and coating.
Coated granules may be developed for applications where the uncoated material requires modification of its surface properties or interaction with the surrounding formulation environment.
The coating should therefore be considered a product-specific feature rather than an inherent property of sorbitol.
Sorbitol is a polyhydric alcohol used as a pharmaceutical excipient. Current USP-NF identifies Sorbitol as d-glucitol with the formula C₆H₁₄O₆, molecular weight 182.17, and CAS Number 50-70-4. The current monograph specifies 91.0–100.5% d-sorbitol calculated on the anhydrous basis.
Sorbitol's high water solubility is an important characteristic for formulation development. FCC describes sorbitol as very soluble in water and slightly soluble in ethanol, methanol, and acetic acid. It is also described as hygroscopic.
In coated granules, the coating can modify how the highly water-soluble sorbitol core interacts with the surrounding environment.
The coating system is one of the most important characteristics of Sorbitol Coated Granules.
Depending on the intended product application, relevant coating attributes may include:
The exact coating system should be identified according to the actual finished-product specification.
A generic coating material or coating percentage should not be stated without product-specific information.
Coating weight gain represents the amount of coating applied relative to the starting granule material. It can be an important process parameter because coating level can influence surface characteristics, moisture interaction, mechanical protection, and dissolution behavior.
The required coating weight gain depends on:
Therefore, a universal coating weight-gain percentage should not be assigned to Sorbitol Coated Granules without an approved product specification.
Uniform coating is important for achieving consistent physical and functional characteristics throughout a batch.
Variation in coating thickness can affect:
Coating uniformity should be evaluated using an appropriate validated method according to the actual product specification.
Particle size is an important attribute for coated granules because it influences surface area, coating requirements, flowability, packing, segregation, and downstream processing.
Potential product-specific parameters include:
A controlled particle-size distribution can help support consistent coating and handling.
The actual D10, D50, D90 and granule-size specifications should be based on the approved finished-product specification.
Bulk density and tapped density provide information about the packing characteristics of Sorbitol Coated Granules.
These properties can influence:
Where actual density measurements are available, additional flow-related parameters such as Carr Index and Hausner Ratio may also be calculated.
Flowability is important when coated granules are transferred, blended, filled, or incorporated into pharmaceutical formulations.
Flow behavior can be influenced by:
The flowability of Sorbitol Coated Granules should be established through appropriate testing rather than assigned a generic classification.
Sorbitol is hygroscopic, making moisture control important during manufacturing, packaging, and storage.
Moisture can affect the physical properties of the sorbitol core and may also influence coating integrity, granule strength, flowability, agglomeration, and storage stability.
The finished-product moisture specification should therefore be established from actual product development and stability data.
Packaging should provide appropriate protection against environmental moisture when required by the validated stability program.
Sorbitol is very soluble in water. However, the dissolution behavior of Sorbitol Coated Granules depends not only on the intrinsic solubility of sorbitol but also on the coating system and granule structure.
The coating may alter the rate at which the surrounding medium reaches the sorbitol core. Factors such as coating thickness, polymer composition, coating uniformity, particle size, porosity, and processing conditions can influence the resulting dissolution behavior.
Specific dissolution claims should therefore be supported by finished-product testing.
Sorbitol Coated Granules can be evaluated during formulation development where a coated, water-soluble pharmaceutical excipient in a controlled granulated format is required.
Development studies may evaluate:
The final formulation should be optimized according to the intended dosage form and performance requirements.
The coated granule format can provide a controlled physical form for pharmaceutical processing.
Depending on the product design, Sorbitol Coated Granules may be evaluated for:
Processing performance depends on particle size, coating characteristics, density, flowability, moisture, and other product-specific properties.
Quality control of Sorbitol Coated Granules should combine the applicable compendial requirements for sorbitol with additional specifications for the finished coated-granule system.
Current USP-NF defines Sorbitol based on d-sorbitol content on the anhydrous basis.
Finished-product quality evaluation may include:
Additional acceptance criteria should be taken from the approved product specification.
Sorbitol Coated Granules can be developed for:
The exact application depends on the coating system, grade, formulation composition, and validated product performance.
Sorbitol Coated Granules are specialized pharmaceutical excipient granules consisting of a sorbitol-based core and a defined coating system.
Current USP-NF identifies Sorbitol as d-glucitol with CAS Number 50-70-4, molecular formula C₆H₁₄O₆, molecular weight 182.17, and a d-sorbitol content requirement of 91.0–100.5% on the anhydrous basis.
FCC describes sorbitol as available in granular form, very soluble in water, and hygroscopic.
For the finished coated granules, the coating composition, coating weight, coating uniformity, particle-size distribution, moisture, flowability, and dissolution characteristics should be controlled according to the actual product specification.
Sorbitol Coated Granules can provide a specialized pharmaceutical excipient format for manufacturers and formulation developers requiring a controlled coated granule system based on a water-soluble sorbitol core.
| Parameter | Specification |
|---|---|
| Appearance | White to off-white granules |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 91.0–100.5% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Individual Impurity | NMT 0.5% |