Formulation Development and Evaluation of Lyophilized Nasal Inserts for Migraine Treatment.

BACKGROUND: Nasal inserts are novel, solid, bioadhesive dosage forms administered via nasal route for prolonged systemic drug delivery. The principle of the dosage form is that, after administration nasal inserts imbibe nasal fluid from the mucosa and form a gel in the nasal cavity in order to avoid foreign body sensation. The objective of this investigation was the development of chitosan/xanthan gum based bioadhesive nasal inserts of antimigraine drug. METHODS: Lyophilization is more usual technique for the preparation of nasal inserts and it is one of the applied methods for drying of solids either in the form of aqueous solution or rarely in the form of aqueous suspension by using freeze dryers. The recent patents on Biocompatible polymer (US20140301972A1), High molecular weight polymers (US20050048121A1), Migraine treatment (WO2009080764A3) helped in selecting the drug and polymers. A 3² factorial design was used to investigate the combined effect of two independent variables such as concentration of Xanthan gum (X1) and the concentration of Chitosan (X2), onto the water uptake, bioadhesion potential and drug release which were the dependent variables. Nine batches of the nasal inserts were developed and evaluated for water uptake at three different pH, bioadhesion potential and drug release. The optimized nasal inserts batch was also characterized by DSC, PXRD and SEM. RESULTS: The results showed that the water uptake ability of nasal insert was strongly influenced by pH of the medium and by polycation/polyanion concentration. This investigation verifies the formation of complexes between chitosan and xanthan gum and confirms the potential of these complexes, in achieving the sustained antimigraine drug delivery in the nasal cavity. CONCLUSION: The best nasal inserts formulation containing chitosan and xanthan gum in the ratio 0.5:0.5, showed desirable % drug release as well as bioadhesion which may result in an increase in the nasal residence time.

The benefit of silicone stents in primary endonasal dacryocystorhinostomy: a systematic review and meta-analysis.

OBJECTIVE: To critically evaluate the evidence comparing success rates of endonasal dacryocystorhinostomy (EN-DCR) with and without silicone tubing and to thus determine whether silicone intubation is beneficial in primary EN-DCR. DESIGN: Systematic review and meta-analysis. SEARCH STRATEGY: A literature search was performed on AMED, EMBASE, HMIC, MEDLINE, PsycINFO, BNI, CINAHL, HEALTH BUSINESS ELITE, CENTRAL and Cochrane Ear, Nose and Throat disorders groups trials register using a combination of various MeSH. The date of last search was January 2016. This review was limited to randomised controlled trials (RCTs) in English language. Risk of bias was assessed using the Cochrane Collaboration's risk of bias tool. Chi-square and I2 statistics were calculated to determine the presence and extent of statistical heterogeneity. EVALUATION METHOD: Study selection, data extraction and risk of bias scoring were performed independently by two authors in concordance with the PRISMA statement. RESULTS: Five RCTs (447 primary EN-DCR procedures in 426 patients) were included for analysis. Moderate interstudy statistical heterogeneity was demonstrated (Chi2 = 6.18; d.f. = 4; I2 = 35%). Bicanalicular silicone stents were used in 229 and not used in 218 procedures. The overall success rate of EN-DCR was 92.8% (415/447). The success rate of EN-DCR was 93.4% (214/229) with silicone tubing and 92.2% (201/218) without silicone tubing. Meta-analysis using a random-effects model showed no statistically significant difference in outcomes between the two groups (P = 0.63; RR = 0.79; 95% CI = 0.3-2.06). CONCLUSIONS: Our review and meta-analysis did not demonstrate an additional advantage of silicone stenting. A high-quality well-powered prospective multicentre RCT is needed to further clarify on the benefit of silicone stents.

Biocalcification using B. pasteurii for strengthening brick masonry civil engineering structures.

Microbiologically induced calcite precipitation in bricks by bacterium Bacillus pasteurii (NCIM 2477) using a media especially optimized for urease production (OptU) was demonstrated in this study. Effect of biocalcification activity on compressive strength and water absorption capacity of bricks was investigated. Various other parameters such as pH, growth profile, urease activity, urea breakdown and calcite precipitated were monitored during the 28 days curing period. Efficiency of B. pasteurii to form microbial aided calcite precipitate in OptU media resulted into 83.9% increase in strength of the bricks as compared to only 24.9% with standard media, nutrient broth (NB). In addition to significant increase in the compressive strength, bricks treated with B. pasteurii grown in OptU media resulted in 48.9 % reduction in water absorption capacity as compared to control bricks immersed in tap water. Thus it was successfully demonstrated that microbial calcification in optimized media by Bacillus pasteurii has good potential for commercial application to improve the life span of structures constructed with bricks, particularly structures of heritage importance.

Biocalcification by Bacillus pasteurii urease: a novel application.

Biocalcification, also known as microbiologically induced calcite precipitation (MICP), is a phenomenon involving the activity of the enzyme urease. A large number of soil microorganisms exhibit urease-producing ability. A novel application of MICP to improve properties of bricks by a soil bacteria Bacillus pasteurii NCIM 2477 was studied. Most of the deterioration of brick structures takes place because of the presence of moisture. Deposition of calcite on the surface and in voids of bricks reduces the water absorption substantially. A favorable effect of microbes to improve the durability of bricks by reducing water absorption was demonstrated as a novel concept in this paper.