Gelken Publishes Guide on Gel Strength and Viscosity for Capsule Dissolution

Gelatin manufacturer Gelken has published a new practical guide aimed at pharmaceutical quality and formulation teams. The document addresses gelatin selection, shell performance, dissolution testing, and material change control.

The guide emphasizes how gelatin's gel strength, measured in Bloom grams, and viscosity are crucial for establishing shell properties that influence consistent capsule manufacture and drug release. It highlights that while higher Bloom generally indicates a more rigid shell, the optimal strength must be matched to the specific capsule type and desired dissolution profile, as overly rigid shells can delay hydration and release.

Gelken explains that viscosity affects how the molten shell behaves during manufacturing and setting, impacting film uniformity and potentially leading to thin spots or pinholes if mismatched with the encapsulation line. The guide clarifies the distinction between shell disintegration, drug dissolution, and bioavailability, while stressing how these parameters are interconnected through shell properties and formulation.

Further details are provided on matching gelatin to different capsule types, including hard two-piece capsules and softgels, considering factors like plasticizer systems and fill compatibility. It also covers modified-release formulations and high-dose fills, advising collaboration with the gelatin manufacturer to align material specifications with intended use and processing conditions.

The guide also addresses managing batch consistency throughout shelf life, recommending narrow, documented specifications for gel strength and viscosity. It advises companies to share capsule type, fill characteristics, and release targets with their gelatin supplier to ensure material suitability and process qualification, ultimately aiming for reliable dissolution results.