SEPISMART™ SR – Time to release your creativity
See the new Seppic product SEPISMART™ SR in use cases with Vitamin C and caffein delivery:
INTESTINAL ABSORPTION – a critical step
1. At physiological pH, vitamin C is mainly found in its ionized form, named ascorbate (Asc) and to a lesser extent in its oxidized form, called dehydroascorbic acid (DHA). Once arrived in the lumen of the small intestine, both chemical forms have to cross the biological membranes of the enterocytes through the brush border. This first step depends mostly on the interaction with 2 different types of transporters.
2. There is a predominant mechanism provided by the Sodium-dependent Vitamin C Transporters (SVCTs) that are dedicated to the transport of Asc only. These transporters are quite similar to each other but are differentially distributed within the body. In the small intestine, SVCT1 is expressed at the apical side of the epithelial cell membrane. It enables the active transport of Asc against a concentration gradient, allowing cumulation in enterocytes. DHA is transported by facilitated diffusion through Glucose Transporters (GLUTs), due to their structural similarities. Once inside the cell, DHA can be easily and rapidly converted in Asc thanks to chemical and enzymatic reduction reactions. At the intracellular level, Asc is therefore dominant.
3. Finally, Asc and DHA can migrate from the enterocytes towards the capillaries. This time, Asc is transported via SVCT2 transporters located at the basolateral membrane. It also allows the reabsorption of Asc from the plasma to the intestinal epithelium. DHA, present in small quantities, is again transported in the blood by GLUTs. DHA transport is competitively inhibited by glucose. Indeed, an excess of glucose in the plasma or in the intestine can block the receptor binding site and thus decrease DHA transport. Within the capillaries, the bloodstream composed mainly of Asc (majority form found at more than 95%) will then supply the various organs of the body.
A second minor mechanism also exists. Indeed, both Asc and DHA can, to a lesser extent, cross the membrane by passive diffusion without transporters according to a concentration gradient.
FINAL STEPS AND CHALLENGES – encountered with vitamin C
Excretion of vitamin C
Every day, blood is filtered by the kidneys. Indeed, blood containing among other things Asc and DHA passes through capillaries of the renal corpuscle and is excreted via the glomerular filtration.
Within the proximal tubule, a reabsorption phenomenon can occur to maintain body homeostasis.
Asc is mainly reabsorbed by active transport by SVCT1 transporters at the apical membrane.
However, a passive diffusion phenomenon also exists.
The reabsorption of DHA seems negligible due to its very low concentration in plasma7.
SEPISMART™ SR – sustained release technology
SEPISMART™ SR is a ready-to-use synergistic co-granulation of
Xanthan and Acacia gums from natural origin.
Formulated with active ingredients (AI) in food supplements, it gives a sustained release effect which allows the release of an effective amount of AI over time and at a continuous rate.
How it works
The sustained release effect of SEPISMART™ SR is based on the mechanism similar to a hydrophilic matrix that is obtained thanks to a specific ratio of xanthan and acacia gums. Once ingested, the SEPISMART™ SR starts its hydration and forms a gel around the core for tablets or around the capsule shell for hard capsules. Depending on the AI characteristics, the dissolution will be mainly by diffusion for soluble AI or by erosion in case of insoluble AI.
Thanks to its mechanism of action, SEPISMART™ SR is as compatible with tablets as with hard capsules formulations.
Benefits of sustained release actives
A PROVEN EFFICIENCY – on sustained release vitamin C food supplements
Methodology
Following USP guideline, the sustained release effect of SEPISMART™ SR has been evaluated in vitamin C food supplement:
Conditions and parameters used:
Quantification of Vitamin C (HPLC)
Determination of the vitamin C released in the dissolution media is performed using chromatographic HPLC method with following parameters :
– Chromatographic column:
Zorbax SB-C18 4.6 x 250mm 5 micron
– Eluent:
water + 0.1% TFAA Isocratic elution
– Injected volume: 20µL
– Temperature: 30°C
– Flux : 1 ml/min
– Detector: VWD lambda 254 nm
– Analysis time: 6 minutes
Test on Vitamin C chemical stability in the gastric fluid
Considering the high solubility of the ascorbic acid (1.9 g/ml at 37°C at pH 1.2, Class 1 BCS), a stability study has been carried out. 125mg of ascorbic acid has been dissolved in 500mL of gastric fluid reproducing the maximum theoretical concentration.
The results confirmed that the method used led to a very low loss of vitamin C.
The graph obtained confirms the sustained release effect of SEPISMART™ SR. Indeed, after one hour of dissolution, only 40% of the vitamin C has been released into the environment. This release kinetic can be accelerated by lowering the % of SEPISMART™ SR.
A UNIQUE SUSTAINED RELEASE EXCIPIENT – for an infinity of applications
percentages of SEPISMART™SR
KEY FACTS
● Excellent aptitude to compression which makes it an effective excipient for tablets.
● Excellent flowability which makes it suitable for hard capsules.For both galenics, SEPISMART™ SR shows a good sustained release effect.
Adjusting the percentage of SEPISMART™ SR allows to fine-tune the release kinetic of caffeine.
25% SEPISMART™SR
KEY FACTS
SEPISMART™ SR has also been tested for the well-known concept of
SLEEP thanks to itsassociation with melatonin!With 25% of SEPISMART™ SR, melatonin is continuously
released from 15 min to 6 hours. This type of sustained release kinetic of
melatonin is adapted for people who are subject to night awakenings.
Download the full brochure on “SEPISMART™ SR brochure” here
(click the picture to download the brochure)
Source: Seppic brochure “SEPISMART™ SR brochure”
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