Micromeritics and release behaviours of cellulose acetate butyrate microspheres containing theophylline prepared by emulsion solvent evaporation and emulsion non-solvent addition method

The present research work compares the effect of microsphere preparation technique on micromeritics and release behaviors of theophylline microspheres. Microspheres were prepared by oil-in oil (O₁/O₂) emulsion solvent evaporation method (ESE) using different ratios of anhydrous theophylline to cellulose acetate butyrate (CAB). Cyclohexane was used as non-solvent to modify the ESE technique (MESE method) and the effect of non-solvent volume on properties of microspheres was investigated. The obtained microspheres were analyzed in terms of drug content, particle size and encapsulation efficiency. The morphology of microsphere was studied using scanning electron microscope. The solid state of microspheres, theophylline and CAB were investigated using X-ray, FT-IR and DSC. The drug content of microspheres prepared by MESE method was significantly lower (15.54% ± 0.46) than microspheres prepared by ESE method (41.08 ± 0.40%). The results showed that as the amount of cyclohexane was increased from 2 mL to 6 mL the drug content of microspheres was increased from 15.54% to 28.71%. Higher encapsulation efficiencies were obtained for microspheres prepared by ESE method (95.87%) in comparison with MESE method (64.71%). Mean particle size of microsphere prepared by ESE method was not remarkably affected by drug to polymer ratio, whereas in MSES method when the volume of cyclohexane was increased the mean particle size of microsphere was significantly decreased. The ratio of drug to polymer significantly changed the rate of drug release from microspheres and the highest drug release was obtained for the microsphere with high drug to polymer ratio. The amount of cyclohexane did not significantly change the drug release. Although, x-ray showed a small change in crystallinity of theophylline in microspheres, DSC results proved that theophylline in microspheres is in amorphous state. No major chemical interaction between the drug and polymer was reported during the encapsulation process.     

Potential roles of chromium on inflammatory biomarkers in diabetes: A Systematic

Diabetes, as a low‐grade chronic inflammatory disease, causes disruption in proper function of immune and metabolic system. Chromium is an important element required for normal lipid and glucose metabolism. Chromium deficiency is correlated with elevation in cardiometabolic risk, which results from increased inflammation. This systematic review was conducted to discover the potential roles of chromium on inflammatory biomarkers. Eligible studies were all in vitro, animal and human studies published in English‐language journals from inception until October 2018. PubMed, Scopus, Embase, ProQuest and Google Scholar databases were searched to fined interventional studies from the effects of chromium on inflammatory biomarkers such as tumour necrosis factor a (TNF‐a), C‐reactive protein (CRP), interleukins, monocyte chemoattractant protein–1 (MCP‐1), intercellular adhesion molecule‐1 (ICAM‐1) and adipocytokines in hyperglycaemia and diabetes. Out of 647 articles found in the search, only 14 articles were eligible for analysis, three in vitro studies, eight animal studies and three human studies. Twelve of the 14 studies included in this review, chromium significantly decreased inflammatory factors. The findings of this review indicate, based on in vitro and in vivo studies, that chromium might have potential anti‐inflammatory properties, but some of the studies did not show anti‐inflammatory effects for chromium (two studies). There are only three studies in humans with controversial results. Therefore, more consistent randomized double‐blind controlled trials are needed to reach relevant clinical recommendations, as well as to determine the precise mechanism, of chromium on inflammation in diabetes.     

Patient satisfaction with occlusal scheme of conventional complete dentures

Occlusal scheme is a controversial topic that has been linked to patient satisfaction with conventional complete dentures (CCDs). This study aimed to compare the patient satisfaction with CCDs with four different occlusal schemes namely the lingualised occlusion (LO), buccalised occlusion (BO), fully bilateral balanced occlusion (FBBO) and partially group function occlusion (PGFO). In this clinical study, new CCDs were made for 121 patients; out of which, 97 patients (mean age of 57.87 ± 9.5 years) completed the 1-year follow-up. The CCD wearers were followed up at 1 month, 3 months and 1 year after CCD delivery. Data were collected via an interview and recorded in a checklist by a blinded examiner. The checklist included the demographic variables, the 19-item version of Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT), and seven 100-mm line visual analogue scales (VASs) to assess the items related to patient satisfaction. The Kruskal-Wallis and Friedman tests followed by post hoc tests were used to compare the variables among the 4 groups and between the 3 follow-ups. P-value ≤ .05 was considered statistically significant for all tests. The patients with BO presented higher satisfaction scores for comfort, stability and retention at the 1-year follow-up compared with PGFO. Both PGFO and FBBO groups had higher physical pain scores compared with BO and LO. The psychological discomfort scores of FBBO group were significantly higher than those in LO group. Pairwise comparisons revealed no significant differences in the general patient satisfaction and total OHIP-EDENT scores between the 4 groups. For most items, within-group analysis showed significant improvement of the satisfaction scores and reduction of domain scores over time.     

Anticonvulsant effect of melatonin through ATP-sensitive channels in mice

Melatonin is a neurohormone secreted principally by the pineal gland. This molecule has various pharmacological properties including improving immune system, prevent cancer, anti-aging, and anti-oxidant effects. The anticonvulsant effects of melatonin have been proved by previous studies. Adenosine triphosphate (ATP)-sensitive potassium (K_ATP) channels are considered as an important target in the seizure modulation. The aim of the present study was to investigate the anticonvulsant effect of melatonin in pentylenetetrazole (PTZ)-induced seizures in mice, focusing on its ability to regulate K_ATP channels. Acute intraperitoneal administration of melatonin (40 and 80 mg/kg) increased clonic seizure threshold induced by intravenous administration of PTZ. Melatonin (40 and 80 mg/kg) increased the latency of clonic seizure and reduced its frequency in mice receiving an intraperitoneal injection of PTZ. Administration of glibenclamide, a K_ATP channels blocker, before intravenous injection of PTZ reduced melatonin anticonvulsant effect. Diazoxide and cromakalim, as K_ATP channels openers, increased antiseizure effect of melatonin in PTZ model of seizures. These findings suggest that the antiseizure effect of melatonin probably is gained through increasing the opening of K_ATP channels.