Colon cancer is the fourth most common cancer globally with 639,000 deaths reported annually. Typical chemotherapy is provided by injection route to reduce tumor growth and metastasis. Recent research investigates the oral delivery profiles of chemotherapeutic agents. In comparison to injection, oral administration of drugs in the form of a colon-specific delivery system is expected to increase drug bioavailability at target site, reduce drug dose and systemic adverse effects. Pectin is suitable for use as colon-specific drug delivery vehicle as it is selectively digested by colonic microflora to release drug with minimal degradation in upper gastrointestinal tract. The present review examines the physicochemical attributes of formulation needed to retard drug release of pectin matrix prior to its arrival at colon, and evaluate the therapeutic value of pectin matrix in association with colon cancer. The review suggests that multi-particulate calcium pectinate matrix is an ideal carrier to orally deliver drugs for site-specific treatment of colon cancer as (1) crosslinking of pectin by calcium ions in a matrix negates drug release in upper gastrointestinal tract, (2) multi-particulate carrier has a slower transit and a higher contact time for drug action in colon than single-unit dosage form, and (3) both pectin and calcium have an indication to reduce the severity of colon cancer from the implication of diet and molecular biology studies. Pectin matrix demonstrates dual advantages as drug carrier and therapeutic for use in treatment of colon cancer.
Dome matrix was designed with gastric and intestinal targeting capacities using melatonin and caffeine as model drugs, and alginate, chitosan and cellulose as composite materials. The melatonin, caffeine and intermediate hydroxypropylmethylcelluose-based dispersible modules were prepared through compaction. Caffeine piled module was capped at both ends with melatonin void modules via intermediate dispersible modules into Dome matrix. Dispersion of intermediate module detached melatonin module from Dome matrix and had it floated in stomach providing a more complete melatonin release due to favorable pH-pKa relationship of dissolution medium and drug. With reference to the caffeine module, the detachment of melatonin module facilitated its gastrointestinal transit as a reduced size matrix, with majority of caffeine delivered in colon. The dual site-targeted and -release Dome matrix is applicable as reference oral carrier for pharmaceutical, nutraceutical, functional food and veterinary medicine where a complex formulation and performancein vivoare required.
Inhalation of Calcium Phosphate nanoparticles (CaPs) has recently unmasked the potential of this nanomedicine for a respiratory lung-to-heart drug delivery targeting the myocardial cells. In this work, we investigated the development of a novel highly respirable dry powder embedding crystalline CaPs. Mannitol was selected as water soluble matrix excipient for constructing respirable dry microparticles by spray drying technique. A Quality by Design approach was applied for understanding the effect of the feed composition and spraying feed rate on typical quality attributes of inhalation powders. The in vitro aerodynamic behaviour of powders was evaluated using a medium resistance device. The inner structure and morphology of generated microparticles were also studied. The 1:4 ratio of CaPs/mannitol led to the generation of hollow microparticles, with the best aerodynamic performance. After microparticle dissolution, the released nanoparticles kept their original size.
The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.