New Study Shows Superior Dissolution Performance of Capsugel’s Thermogelled HPMC Capsules

October 17, 2012

MORRISTOWN, N.J. Oct. 17, 2012– New data presented today at the American Association of Pharmaceutical Sciences Annual Meeting and Exposition show that plant-based capsules made from Hypromellose (HPMC), manufactured using a thermal gelling process instead of one with gelling agents, have a faster and more predictable dissolution profile that is independent of the dissolution media. 

“Today’s findings confirm that plant-based HPMC capsules can be manufactured to produce consistent rates of dissolution independent of the dissolution media relative to both pH or cation nature and content while also providing a stable environment for moisture-sensitive ingredients,” said Dominique Cade, Ph.D., who presented today’s poster titled “Hypromellose Hard Capsules Dissolution.” Dr. Cade is theDirector of Polymer Science for the Research and Development department at Capsugel. “This is an important proof of concept in alternate polymer science that will benefit current and future products requiring gelatin-like performance in an alternate polymer.”  

In the study, researchers compared the in vitro dissolution performance of commercially available HPMC hard capsules using different media. The test results reveal that with a pH1.2 USP medium, the simple switch from 2 g NaCl/L to 2 g KCl/L causes a significant delay in the dissolution of capsules with kappa-carrageenan, the most commonly used gelling system. For the Hypromellose capsules manufactured with carrageenan as a gelling agent, the quantity of caffeine released after 30 minutes was less than 50% in comparison to Hypromellose capsules manufactured without a gelling agent which released more than 90% in the same time period. The same change occurred when using the simulated milk fluid: the release after 30 minutes was less than 30% compared to more than 90% for the HPMC without the gelling system. 

Gelatin capsules are produced by dipping a mold pin into hot liquid gelatin. The HPMC polymer has reasonable flexibility and with the use of a secondary gelling agent, capsule manufacturers can generate quick setting HPMC. An issue with the use of secondary gelling systems is that they can interact with dissolution media causing delayed drug release that may be undesirable during product development. “It is well established that the gelling of carrageenan is strongly enhanced by some cations, notably potassium and calcium. Within the stomach, the presence of foods containing potassium or calcium could cause an interaction that would delay or change the product release,” Cade concluded.  

To develop an HPMC capsule without using a gelling agent, Capsugel scientists assessed the impact of the mold pin temperature and conditions to achieve optimal capsule drying. From these studies, a proprietary thermal gelling process was developed that eliminated the need to use a gelling agent and salts as co-gelling agents. The resulting capsules are known as Vcaps® Plus capsules.

Dr. Cade will share additional research related to dissolution and disintegration methods for capsules during a AAPS symposium on Thursday, October 18 from 9:00 to 11:00 am CT titled “Dissolution and Disintegration Methods for Gelatin Capsules, Including Dietary Supplements (APQ.)” Dr. Cade’s presentation is “Issues Relating to Capsules Testing in Nutraceuticals.”

Capsugel is a global leader in innovative dosage forms and solutions for the healthcare industry. Offering a comprehensive array of products and services, from hard gelatin, liquid-filled, and vegetarian capsules, to innovative R&D product development services, Capsugel is at the forefront of drug delivery innovation providing support to customers from formulation to final production. For more information about Capsugel, visit