A dynamic in vitro oral mastication system to study the oral processing behavior of soft foods.

A bolus-oriented artificial oral mastication system was developed to simulate the dynamics of food mastication in the human mouth. The system consists of a chewing unit, a bolus forming unit, and provisions for the dynamic incorporation of saliva during mastication. The system performance was validated with in vivo trials (n = 25) considering time-dependent changes in particle size, textural attributes and rheological behavior of the bolus. Idli, a fermented and steamed black gram-rice-based Indian food was considered the model soft food for all trials measured in triplicates. The mastication dynamics were evaluated by analyzing bolus properties during every 3 s of mastication. Large strain shear rheology tests revealed that the viscosity of the sample decreased over time. Results of in vivo trials follow close trends in particle size and rheological behavior and have no significant change in correlation with in vitro mastication results. Similar observations were made in the half softening time of idli during mastication as determined using the relative change in hardness (hardness ratio (Ht/H0)) values fitted to the Weibull model. Also, a model to simulate the time-dependent changes in bolus adhesiveness was developed.

Determining the glycaemic responses of foods: conventional and emerging approaches.

A low-glycaemic diet is crucial for those with diabetes and cardiovascular diseases. Information on the glycaemic index (GI) of different ingredients can help in designing novel food products for such target groups. This is because of the intricate dependency of material source, composition, food structure and processing conditions, among other factors, on the glycaemic responses. Different approaches have been used to predict the GI of foods, and certain discrepancies exist because of factors such as inter-individual variation among human subjects. Besides other aspects, it is important to understand the mechanism of food digestion because an approach to predict GI must essentially mimic the complex processes in the human gastrointestinal tract. The focus of this work is to review the advances in various approaches for predicting the glycaemic responses to foods. This has been carried out by detailing conventional approaches, their merits and limitations, and the need to focus on emerging approaches. Given that no single approach can be generalised to all applications, the review emphasises the scope of deriving insights for improvements in methodologies. Reviewing the conventional and emerging approaches for the determination of GI in foods, this detailed work is intended to serve as a state-of-the-art resource for nutritionists who work on developing low-GI foods.

Prediction of in-vitro glycemic responses of biscuits in an engineered small intestine system.

The Glycemic Index (GI) indicates the effect of a food product on the increase/decrease in postprandial blood glucose levels. Monitoring the glycemic response is important, as it is associated with the human nutrition absorption. However, human or animal blood sampling involves financial, ethical, and other challenges. Accordingly, in the recent past, many human digestion models have been developed to understand the intricate changes that occur during human digestion and absorption processes. Dynamic models help in studying the digestion mechanics and hypotheses related to the health effects of food ingredients in controlled conditions. The objective of this study is to predict the GI of different biscuit composition using an engineered small intestine system, considering a mass transfer approach and in-silico simulation. Different GI was predicted for biscuits: 62 for plain biscuits (N) containing only refined wheat flour; 57 for finger millet flour biscuits (F); 51 for wheat bran fortified biscuits (W). The results were close to human in-vivo values; GI of 76 for plain biscuits (N); 58 for finger millet biscuits (F) and 41 for wheat bran fortified (W) biscuits, respectively (with no significant difference in the GI values of Engineered model and human glucose blood sampling results) which was confirmed with Bland-Altmann statistics. This finding will help in predicting the glycemic response of new biscuit products serving as an alternative approach to human blood sampling for GI analysis.

Development of albumin-based nanoparticles for the delivery of abacavir.

The study was designed to prepare and evaluate albumin nanoparticles containing antiviral drug abacavir sulphate. Various batches of albumin nanoparticles containing abacavir sulphate were prepared by desolvation method. The abacavir loaded particles were characterized for their yield, percentage of drug loading, surface morphology, particle size, surface charge, pattern of in vitro drug release and release mechanism studies. Drug loading ranged from 1.2 to 5.9%w/w. The mean particle size and the surface charge were 418.2nm and -40.8mV respectively. The in vitro drug release varied between 38.73 and 51.36%w/w for 24h. The n value for Korsmeyer-Peppas was 0.425 indicating Fickian type drug release. The preliminary findings indicated that albumin nanoparticles of abacavir can be prepared by desolvation method with good yield, high drug loading and sustained release.

Albumin nanoparticles for the delivery of gabapentin: preparation, characterization and pharmacodynamic studies.

The study was aimed to prepare and evaluate gabapentin loaded albumin nanoparticles and to find out their effectiveness in treating epilepsy. Albumin nanoparticles of gabapentin were prepared by pH-coacervation method. The drug was administered into animals as free drug, gabapentin bound with nanoparticles, and gabapentin bound with nanoparticles coated with polysorbate 80. The polysorbate 80 coated nanoparticles increased the gabapentin concentration in the brain about 3 fold in comparison with the free drug. Moreover, the polysorbate 80 coated nanoparticles significantly reduced the duration of all phases of convulsion in both maximal electroshock induced and pentylenetetrazole induced convulsion models in comparison with free drug and drug bound with nanoparticle formulations, which indicates the ability of polysorbate 80 coated nanoparticles to enhance the gabapentin concentration in the brain.

Sustained release enteric coated tablets of pantoprazole: formulation, in vitro and in vivo evaluation.

In this study, an attempt was made to deliver pantoprazole in a sustained manner using delayed release tablets. The tablets were prepared by the wet granulation method using HPMC, cassava starch and polyvinyl pyrrolidine as polymers, Avicel PH 102 (MCC) as filler and potato starch as binder. The prepared tablets were evaluated for hardness, mass variation, friability and drug content uniformity, and the results were found to comply with official standards. The prepared tablets were coated using an enteric coating polymer such as cellulose acetate phthalate, Eudragit L100 and drug coat L100 by the dip coating method. The in vitro release was studied using pH 1.2 acidic buffer and pH 6.8 phosphate buffer and the study revealed that the prepared tablets were able to sustain drug release into the intestine. The anti-ulcer activity was evaluated by a water immersion stress induced ulcer model. The enteric coated pantoprazole tablets significantly reduced ulcer formation.

Nanoparticles based on albumin: preparation, characterization and the use for 5-flurouracil delivery.

The aim of the study was to formulate and evaluate nanoparticles based on albumin to deliver 5-fluorouracil. The nanoparticles were prepared by coacervation method. The nanoparticles were characterized for particle size, surface charge, size distribution and drug loading capacity. The drug loading capacity varied from 4.22% to 19.8% (w/w). The mean particle size was 141.9 nm and surface charge was -30.3 mV. The drug loaded particles exerted a bi-phasic release pattern with an initial burst effect followed by a sustained release in pH 7.4 phosphate buffer. The drug release was first order diffusion controlled and the mechanism was Fickian. The drug loaded nanoparticles showed superior cytotoxicity when compared to the free drug.