Combined Application of MRI and the Salivary Tracer Technique to Determine the in Vivo Disintegration Time of Immediate Release Formulation Administered to Healthy, Fasted Subjects.

The process of disintegration is a crucial step in oral drug delivery with immediate release dosage forms. In this work, the salivary tracer technique was applied as a simple and inexpensive method for the investigation of the in vivo disintegration time of hard gelatin capsules filled with caffeine. The disintegration times observed with the salivary tracer technique were verified by magnetic resonance imaging (MRI). After an overnight fast of at least 10 h and caffeine abstinence of minimum 72 h, conventional hard gelatin capsules containing 50 mg caffeine and 5 mg iron oxide were administered to 8 healthy volunteers. For the period of 1 h after capsule intake, subjects were placed in supine position in the MRI scanner, and scans were performed in short time intervals. Each MRI measurement was directly followed by saliva sampling by drooling. Salivary caffeine concentrations were determined by high performance liquid chromatography followed by mass spectrometric detection (LC/MS-MS). The time point of capsule disintegration was determined by visual inspection of the MR images as well as by an increase in the salivary caffeine concentration. The results indicated that the difference in mean disintegration times of the capsules as determined by the two in vivo methods was around 4 min (8.8 min for MRI vs 12.5 min for saliva). All disintegration times determined by the salivary tracer technique were slightly higher. This delay could be explained by the fact that the appearance of caffeine in saliva required drug absorption in the small intestine. Because capsule disintegration happened mainly in the stomach, the exact site of disintegration as well as the processes of gastric mixing and gastric emptying contributed to the delay between the two methods. This work demonstrated the feasibility of the salivary tracer technique to investigate the in vivo disintegration of immediate release dosage forms in a simple and reliable manner.

Effects of extracts and compounds from Tricholoma populinum Lange on degranulation and IL-2/IL-8 secretion of immune cells.

Tricholoma populinum Lange is an edible basidiomycete from the family Tricholomataceae. Extracts, fractions, and different metabolites isolated from the fruiting bodies of this mushroom were tested for degranulation-inhibiting activities on RBL-2H3 cells (rat basophils). Dichloromethane extracts decreased degranulation significantly, as did a fraction after column chromatography. In addition, the extract decreased the IL-2 release from Jurkat T cells and the release of IL-8 from HMC-1 human mast cells. The results show the significant effects of extracts of T. populinum on cells of the innate (basophils and mast cells) and adaptive (T cells) immune system and indicate the influence of the mushroom on different immunological processes. As one fraction showed activity, it seems to be possible that it includes an active principle. The compounds responsible for this effect, however, could not be identified as the contents oleic acid (1), ergosterol peroxide (2), and 9,11-dehydroergosterol peroxide (3) showed no effects. Nevertheless, the mushroom could be used for supporting allergy treatment in future studies.

In vivo characterization of enTRinsic™ drug delivery technology capsule after intake in fed state: A cross-validation approach using salivary tracer technique in comparison to MRI.

The instability of various small molecules, vaccines and peptides in the human stomach is a complex challenge for oral drug delivery. Recently, a novel gastro-resistant capsule - the enTRinsic™ Drug Delivery Technology capsule - has been developed. In this work, the salivary tracer technique based on caffeine has been applied to study the in vivo disintegration of enTRinsic™ capsules in 16 healthy volunteers. In addition, magnetic resonance imaging (MRI) was used to visualize GI transit and to verify the disintegration times determined by using the salivary tracer technique. The enTRinsic™ capsules filled with 50mg of caffeine and 5mg of black iron oxide were administered in the fed state, i.e. 30min after a light meal (500kcal). In the first hour after capsule intake, the subjects were placed in supine position in the MRI scanner and scans were performed in short time intervals. After 1h, the subjects could leave the MRI scanner in between the MRI measurements, which were performed every 15min until disintegration of the capsule was confirmed (maximum observation time: 8h). Saliva samples were obtained simultaneously with MR imaging. Caffeine concentrations in saliva were determined by LC/MS-MS. The starting point of capsule disintegration was determined visually by inspection of the MR images as well as by the onset of salivary caffeine concentrations. In 14 out of 16 subjects, the capsule disintegrated in the small intestine. In one subject, the enTRinsic™ capsule was not emptied from the stomach within the observation time. In another subject, disintegration occurred during gastric emptying in the antropyloric region. In this study, we demonstrated that the enTRinsic™ capsules are also gastro resistant when taken under fed state conditions. Furthermore, we demonstrated the feasibility of using low dose caffeine as a salivary tracer for the determination of the disintegration of an enteric formulation.

Low dose caffeine as a salivary tracer for the determination of gastric water emptying in fed and fasted state: A MRI validation study.

Improving our knowledge about human gastrointestinal physiology and its impact on oral drug delivery is crucial for the development of new therapies and effective drug delivery systems. The aim of this study was to develop an in vivo tool to determine gastric emptying of water by administration of a caffeine as a tracer substance followed by subsequent saliva caffeine analysis. For this purpose, 35 mg of caffeine were given to six healthy volunteers after a 10 h overnight together with 240 mL of tap water either on a fasted stomach or 30 min after the high-caloric, high-fat breakfast recommended for bioavailability/bioequivalence (BA/BE) studies. Caffeine was administered in form of an ice capsule in order to omit the contamination of the oral cavity with caffeine. Parallel to saliva sampling, magnetic resonance imaging (MRI) was applied in order to validate this novel approach. After administration of the ice capsule, MRI measurements were performed every 2 min for the first 20 min followed by further measurements after 25, 30, 35, 40, 50 and 60 min. Saliva samples were collected always 1 min after the MRI measurement in supine position in the MRI scanner and continued for further 240 min. The caffeine concentration in saliva was quantified after liquid-liquid extraction by a validated HPLC/MS-MS method. The obtained MRI data revealed a fast emptying of the co-administered water within 10 to 50 min in the fasted state and likewise in the fed state. Salivary caffeine kinetics showed a Cmax from 150 to 400 ng/mL with a tmax from 20 to 90 min. MRI data were normalized by setting the maximum emptied volume to 100% and the salivary caffeine kinetics were normalized by setting Cmax to 100%. In order to compare the results obtained by the MRI and the saliva method, the normalized data for each volunteer was correlated based on a linear regression. In the fasted state the mean slope for six comparisons was 0.9114 ±â€¯0.1500 and the mean correlation coefficient was 0.912 ±â€¯0.055. In the fed state, a mean slope of 0.8326 ±â€¯0.1630 and a mean correlation coefficient of 0.887 ±â€¯0.047 were obtained. Based on these results, we could show that salivary caffeine concentrations are suitable to describe the emptying of water as a non-caloric liquid from the fasted and the fed stomach. The presented technique provides a straight-forward, inexpensive and noninvasive method to assess gastric emptying of hydrophilic liquids, which can be broadly used in oral biopharmaceutics. Possible applications are the characterization of real-life conditions, specific populations (e.g. elderly people) and the better understanding of the contribution of gastric emptying to pharmacokinetic profiles of orally administered drugs.

Ergosterol Peroxide: A Mushroom-Derived Compound with Promising Biological Activities-A Review.

Ergosterol peroxide (EP; 5α,8α-epidioxy-22E-ergosta-6,22-dien-3ß-ol) is a C28-sterol and a component of many medicinal mushrooms. Since its discovery nearly a century ago, many sources and biological effects of this compound have been described. Effects range from antimicrobial to cytotoxic to immunosuppressive and other activities. This review covers biological investigations of EP, its activities, and possible mechanisms of action. EP is a promising candidate for drug development and contributes to the health-promoting effects of medicinal mushrooms.

Development and Validation of an LC-MS/MS Method for the Quantification of Agaritine in Mushrooms.

Agaritine, an aromatic hydrazine, is found as a secondary metabolite in mushroom species. It is among others suspected to exhibit genotoxic activity. This publication describes the validation of a method for the quantification of agaritine in mushrooms (i.e., extraction and purification by solid phase extraction) and measurement by liquid chromatography with tandem mass spectrometry detection in positive ionization mode. The results show this method to be selective, accurate, and precise. This method could be used for the quality control of pharmaceutical preparations containing mushrooms.