The focus of this review is to provide an overview of the chitosan based nanoparticles for various non-parenteral applications and also to put a spotlight on current research including sustained release and mucoadhesive chitosan dosage forms. Chitosan is a biodegradable, biocompatible polymer regarded as safe for human dietary use and approved for wound dressing applications. Chitosan has been used as a carrier in polymeric nanoparticles for drug delivery through various routes of administration. Chitosan has chemical functional groups that can be modified to achieve specific goals, making it a polymer with a tremendous range of potential applications. Nanoparticles (NP) prepared with chitosan and chitosan derivatives typically possess a positive surface charge and mucoadhesive properties such that can adhere to mucus membranes and release the drug payload in a sustained release manner. Chitosan-based NP have various applications in non-parenteral drug delivery for the treatment of cancer, gastrointestinal diseases, pulmonary diseases, drug delivery to the brain and ocular infections which will be exemplified in this review. Chitosan shows low toxicity both in vitro and some in vivo models. This review explores recent research on chitosan based NP for non-parenteral drug delivery, chitosan properties, modification, toxicity, pharmacokinetics and preclinical studies.

Nosocomial infections caused by extensively drug-resistant (XDR) or Pan-Drug resistant (PDR) Acinetobacter (A.) baumannii have recently increased dramatically creating a medical challenge as therapeutic options became very limited. The aim of our study was to investigate the antibiotic-resistance profiles and evaluate the various combinations of ciprofloxacin (CIP) or levofloxacin (LEV) with antimicrobial agents and non-antimicrobial agents to combat antimicrobial resistance of XDR A. baumannii. A total of 100 (6.25%) A. baumannii clinical isolates were recovered from 1600 clinical specimens collected from hospitalized patients of two major university hospitals in Upper Egypt. Antimicrobial susceptibility tests were carried out according to CLSI guidelines. Antimicrobial susceptibility testing of the respective isolates showed a high percentage of bacterial resistance to 19 antimicrobial agents ranging from 76 to99%. However, a lower percentage of resistance was observed for only colistin (5%) and doxycycline (57%). The isolates were categorized as PDR (2; 2%), XDR (68; 68%), and multi-drug resistant (MDR) (30; 30%). Genotypic analysis using ERIC-PCR on 2 PDR and 32 selected XDR isolates showed that they were not clonal. Combinations of CIP or LEV with antibiotics (including, ampicillin, ceftriaxone, amikacin, or doxycycline) were tested on these A. baumannii non-clonal isolates using standard protocols where fractional inhibitory concentrations (∑FICs) were calculated. Results of the respective combinations showed synergism in 23.5%, 17.65%, 32.35%, 17.65% and 26.47%, 8.28%, 14.71%, 26.47%, of the tested isolates, respectively. CIP or LEV combinations with either chlorpromazine (CPZ) 200 μg/ml, propranolol (PR) in two concentrations, 0.5 mg/ml and 1.0 mg/ml or diclofenac (DIC) 4 mg/ml were carried out and the MIC decrease factor (MDF) of each isolate was calculated and results showed synergism in 44%, 50%, 100%, 100% and 94%, 85%, 100%, 100%, of the tested isolates, respectively. In conclusion, combinations of CIP or LEV with CPZ, PR, or DIC showed synergism in most of the selected PDR and XDR A. baumannii clinical isolates. However, these combinations have to be re-evaluated in vivo using appropriate animal models infected by XDR-or PDR-A. baumannii.

Raynaud’s Phenomenon is a vascular affliction resulting in pain and blanching of the skin caused by excessive and prolonged constriction of arterioles, usually due to cold exposure. Nifedipine is a vasodilatory calcium channel antagonist, which is used orally as the first-line pharmacological treatment to reduce the incidence and severity of attacks when other interventions fail to alleviate the condition and there is danger of tissue injury. Oral administration of nifedipine, however, is associated with systemic adverse effects, and thus topical administration with nifedipine locally to the extremities would be advantageous. However, nifedipine is subject to rapid photodegradation, which is problematic for exposed skin such as the hands. The goal of this project was to analyze the photostability of a novel topical nifedipine cream to UVA light. The effect of incorporating the photoprotectants rutin, quercetin, and/or avobenzone (BMDBM) into the nifedipine cream on the stability of nifedipine to UVA light exposure and the appearance of degradation products of nifedipine was determined. Rutin and quercetin are flavonoids with antioxidant activity. Both have the potential to improve the photostability of nifedipine by a number of mechanisms that either quench the intermolecular electron transfer of the singlet excited dihydropyridine to the nitrobenzene group or by preventing photoexcitation of nifedipine. Rutin at either 0.1% or 0.5% (w/w) did not improve the stability of nifedipine 2% (w/w) in the cream after UVA exposure up to 3 h. Incorporation of quercetin at 0.5% (w/w) did improve nifedipine stability from 40% (no quercetin) to 77% (with quercetin) of original drug concentration after 3 h UVA exposure. A combination of BMDBM and quercetin was the most effective photoprotectant for maintaining nifedipine concentration following up to 8 h UVA exposure.

Among bacterial species implicated in hospital-acquired infections are the emerging Pan-Drug Resistant (PDR) and Extensively Drug-Resistant (XDR) Acinetobacter (A.) baumannii strains as they are difficult to eradicate. From 1600 clinical specimens, only 100 A. baumannii isolates could be recovered. A high prevalence of ≥ 78% resistant isolates was recorded for the recovered isolates against a total of 19 tested antimicrobial agents. These isolates could be divided into 12 profiles according to the number of antimicrobial agents to which they were resistant. The isolates were assorted as XDR (68; 68%), Multi-Drug Resistant (MDR: 30; 30%), and PDR (2; 2%). Genotypically, the isolates showed three major clusters with similarities ranging from 10.5 to 97.8% as revealed by ERIC-PCR technique. As a resistance mechanism to fluoroquinolones (FQs), target site mutation analyses in gyrA and parC genes amplified from twelve selected A. baumannii isolates and subjected to sequencing showed 12 profiles. The selected isolates included two CIP-susceptible ones, these showed the wild-type profile of being have no mutations. For the ten selected CIP-resistant isolates, 9 of them (9/10; 90%) had 1 gyrA/1 parC mutations (Ser 81 → Leu mutation for gyrA gene and Ser 84 → Leu mutation for parC gene). The remaining CIP-resistant isolate (1/10; 10%) had 0 gyrA/1 parC mutation (Ser 84 → Leu mutation for parC gene). Detection of plasmid-associated resistance genes revealed that the 86 ciprofloxacin-resistant isolates carry qnrA (66.27%; 57/86), qnrS (70.93%; 61/86), aac (6')-Ib-cr (52.32%; 45/86), oqxA (73.25%; 63/86) and oqxB (39.53%; 34/86), while qepA and qnrB were undetected in these isolates. Different isolates were selected from profiles 1, 2, and 3 and qnrS, acc(6,)-ib-cr, oqxA, and oqxB genes harbored by these isolates were amplified and sequenced. The BLAST results revealed that the oqxA and oqxB sequences were not identified previously in A. baumannii but they were identified in Klebsiella aerogenes strain NCTC9793 and Klebsiella pneumoniae, respectively. On the other hand, the sequence of qnrS, and acc(6,)-ib-cr showed homology to those of A. baumannii. MDR, XDR, and PDR A. baumannii isolates are becoming prevalent in certain hospitals. Chromosomal mutations in the sequences of GyrA and ParC encoding genes and acquisition of PAFQR encoding genes (up to five genes per isolate) are demonstrated to be resistance mechanisms exhibited by fluoroquinolones resistant A. baumannii isolates. It is advisable to monitor the antimicrobial resistance profiles of pathogens causing nosocomial infections and properly apply and update antibiotic stewardship in hospitals and outpatients to control infectious diseases and prevent development of the microbial resistance to antimicrobial agents.

Two chitosan-coated nanoparticles formulations of MMF had high EE and a desirable sustained drug release profile in the effort to design a once-daily dosage form for MMF.

Purpose Hyperbaric bupivacaine (0.75% in dextrose) is used for spinal obstetric anesthesia. Occasional clusters of anesthetic failures occur in this setting, not readily attributable to clinical factors. We hypothesized that cold temperature exposure is related to bupivacaine instability. Methods An electronic survey was distributed to Canadian anesthesiologists to determine consistencies in spinal anesthesia practice, and to invite submission of failed bupivacaine samples for analysis. Another survey for hospital pharmacists focused on bupivacaine logistics. Ultraviolet (UV) spectrometry, differential scanning calorimetry, and high performance liquid chromatography were used to evaluate the effect of temperature on bupivacaine chemical stability. Mass spectrometry (MS) was used to observe bupivacaine and dextrose degradation in laboratory samples of hyperbaric 0.75% bupivacaine in dextrose. Hyperbaric bupivacaine that failed to produce adequate anesthesia in labour and delivery patients was subject to tandem MS/MS analysis on commonly observed ions to look for ion patterns consistent with bupivacaine degradation products and to compare with laboratory samples subjected to cold temperatures. Results Canadian obstetric anesthesiologists report similar practices and use hyperbaric bupivacaine for spinal anesthesia. Pharmacists surveyed indicated facility storage at room temperature but variable temperatures during shipping. No standard procedure for failure reporting was identified. Analysis of bupivacaine showed a slight decrease in bupivacaine concentration or UV spectral changes after incubation at temperatures B 4°C. Mass spectrometric analysis of hyperbaric bupivacaine from failed spinal anesthesia cases showed complex and inconsistent patterns of ion formation, and different from the ion patterns observed for cooled vs uncooled bupivacaine solutions. Temperature-related changes were noted for dextrose in cooled samples in which dextroserelated ions were formed. Conclusions Canadian clinical practice and handling of hyperbaric bupivacaine is consistent. Most respondents indicated an interest in a formal reporting and collection process. Cold exposure did not degrade bupivacaine. A complex and possibly inconsistent reaction involving dextrose was identified that requires further analysis of a larger sample size to elucidate the mechanisms. RésuméObjectif La bupivacaïne hyperbare (0,75 % dans du dextrose) est utilisée pour l'anesthésie obstétricale rachidienne. Il arrive parfois que plusieurs anesthésies rapprochées soient inefficaces dans cette situation, et ces Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12630-019-01343-6) contains supplementary material, which is available to authorized users.

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Background and Aims SARS-CoV-2 infection has been recorded in 230 countries to date. Obesity has a negative impact on one’s quality of life and is one of the main causes of mortality globally. Obesity affects the immune system, making the host more susceptible to infectious infections. Also, obesity commonly provokes the severity of respiratory diseases so the correlation of LEP rs7799039 Polymorphism in corpulent patients with COVID-19 infection was clearly investigated in the current study. Methods A total of 232 patients were recruited, 116 patients were obese with COVID-19 infection, and 116 patients were non obese COVID-19. Fasting blood glucose test (FBG), hemoglobin A1C (HbA1C), complete blood count (CBC), international normalized ratio (INR), urea, alanine transaminase (ALT), aspartate aminotransferase (AST), D dimer and C-reactive protein (CRP) were estimated. C.T. scan was performed for each patient, and C.T. severity score was calculated. Genotyping for the leptin rs7799039 SNPs was performed by TaqMan ® (Applied Biosystems Step One TM Real-time PCR). Results Regarding LEP polymorphism, all individuals of non-obese groups significantly had the homozygous allele GG (100%), whereas only 56% of obese groups had GG alleles (P = 0.001). The severity scores significantly (P = 0.001) varied regarding LEP polymorphism regarding Rs7799039, where the largest proportion of those with Grade IV had the homozygous allele AA (57.1%). Conclusion There was a correlation between the leptin gene allelic discrimination and COVID-19 CT brutality in obese patients. The A allele was considered a risk factor for severity in COVID-19 patients while the G allele contributes to decreasing that risk.