Factorial effect of process parameters on pharmaceutical characteristics of biodegradable PLGA microparticles

Among the drug delivery strategies intended to increase the bioavailability of drugs, the use of polymeric biodegradable microcarriers has shown a significant degree of success.The purpose of this study was developing a polymeric drug delivery system for a model drug: furosemide, which belongs to class IV of BCS (low solubility and low permeability), intended to oral administration and improving the stability and intestinal absorption of the drug.To achieve this goal, furosemide loaded poly (lactic-co-glycolic acid) (PLGA) microparticles were prepared by solvent evaporation method and characterized. To obtain an appropriate mathematical model with minimum experiments for optimization of formulation, a 24 full factorial design based on four independent variables (amount of polymer, emulsifier, volume of internal and external phases) was used to plan the experiments. The effects of these parameters on the drug loading efficiency were investigated. The release profiles of furosemide from microparticles were examined in simulated gastric fluid (SGF pH 1.2), simulated intestinal fluid (SIF pH 7.4) and phosphate buffer (pH: 7.4).The results of optimized formulation showed a narrow size distribution with an average diameter of 60 ± 5 μm and a drug loading of more than 60%. In simulated gastric fluid (SGF), less than 8% of furosemide was released from microparticles in 24 h and about 60% and 50% furosemide was released in 24 h in simulated intestinal fluid (SIF) and phosphate buffer, respectively.Results from this preliminary work showed that furosemide loaded PLGA microparticles can be successfully obtained through solvent-evaporation technique, with good morphological characteristics, high encapsulation efficiency and controlled drug release profile suitable for per oral administration.Keywords: Furosemide; PLGA microparticles; Full factorial design

Factorial effect of process parameters on pharmaceutical characteristics of biodegradable PLGA microparticles

Among the drug delivery strategies intended to increase the bioavailability of drugs, the use of polymeric biodegradable microcarriers has shown a significant degree of success.The purpose of this study was developing a polymeric drug delivery system for a model drug: furosemide, which belongs to class IV of BCS (low solubility and low permeability), intended to oral administration and improving the stability and intestinal absorption of the drug.To achieve this goal, furosemide loaded poly (lactic-co-glycolic acid) (PLGA) microparticles were prepared by solvent evaporation method and characterized. To obtain an appropriate mathematical model with minimum experiments for optimization of formulation, a 24 full factorial design based on four independent variables (amount of polymer, emulsifier, volume of internal and external phases) was used to plan the experiments. The effects of these parameters on the drug loading efficiency were investigated. The release profiles of furosemide from microparticles were examined in simulated gastric fluid (SGF pH 1.2), simulated intestinal fluid (SIF pH 7.4) and phosphate buffer (pH: 7.4).The results of optimized formulation showed a narrow size distribution with an average diameter of 60 ± 5 μm and a drug loading of more than 60%. In simulated gastric fluid (SGF), less than 8% of furosemide was released from microparticles in 24 h and about 60% and 50% furosemide was released in 24 h in simulated intestinal fluid (SIF) and phosphate buffer, respectively.Results from this preliminary work showed that furosemide loaded PLGA microparticles can be successfully obtained through solvent-evaporation technique, with good morphological characteristics, high encapsulation efficiency and controlled drug release profile suitable for per oral administration.Keywords: Furosemide; PLGA microparticles; Full factorial design

Nucleation and crystallization in bio-based immiscible polyester blends

Bio-based thermoplastic polyesters are highly promising materials as they combine interesting thermal and physical properties and in many cases biodegradability. However, sometimes the best property balance can only be achieved by blending in order to improve barrier properties, biodegradability or mechanical properties. Nucleation, crystallization and morphology are key factors that can dominate all these properties in crystallizable biobased polyesters. Therefore, their understanding, prediction and tailoring is essential. In this work, after a brief introduction about immiscible polymer blends, we summarize the crystallization behavior of the most important bio-based (and immiscible) polyester blends, considering examples of double-crystalline components. Even though in some specific blends (e.g., polylactide/polycaprolactone) many efforts have been made to understand the influence of blending on the nucleation, crystallization and morphology of the parent components, there are still many points that have yet to be understood. In the case of other immiscible polyester blends systems, the literature is scarce, opening up opportunities in this environmentally important research topic.The authors would like to acknowledge funding by the BIODEST project ((RISE) H2020-MSCA-RISE-2017-778092

Disposable sensors in diagnostics, food and environmental monitoring

Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities

Preparation and physicochemical evaluation of topical formulations of purified curcuminoids from Curcuma longa rhizome

Background and objectives: The purpose of this study was optimization of semisolid topical formulation from ethanol extract of turmeric and evaluation of rheological characterization and investigation of physicochemical control tests. Methods: The ethanolic extract was prepared with Soxhlet method and the compounds were isolated with silica gel column chromatography. Isolation of curcuminoids was accomplished by preparative HPLC.  The accelerated and real time stability tests for the formulations were investigated at 40±2 °C/70% RH for 90 days and 30±2° C/35%±5 RH for 12 month, respectively. Results: The yield of pure curcuminoids was 0.8%.The results of rheograms at 25° C showed pseudoplastic, plastic and pseudoplastic behavior for the ointment, cream and gel formulations respectively. The pH was measured by using  a  digital  type  of  pH  meter  by  dipping  the  glass electrical probe  for all of formulation, and the consequences exhibited PH values of 6.6, 6.8 and 6.9for the ointment, cream and gel, respectively. The results of cumulative release (µg/cm2) for ointment, cream and gel formulation achieved with dissolution media which contained buffer phosphate with pH 7.2 and 1% tween 20 after 24 h were 693.6, 648.5 and 650.5, respectively. Discussion:  The advantage of this method extraction compared to previously described methods, was utilizing safer solvent for extraction. The cumulative release of formulation and drug content during the physicochemical control tests was compared with commercial product and showed no significant different (p˃ 0.05).The formulations of this study showed functional and physical stability in the period of the study

The quantitative ultrasound study of tongue shape and movement in normal Persian speaking children

Objectives: Ultrasound research on speech production in normal speakers has long used quantitative measurements in different languages. However, no studies in this area have been conducted in the Persian language. This study investigated Persian speaking children scores on two single curve measures of tongue shape, based on midsagittal tongue shape data from ultrasound imaging. Methods: This is a cross-sectional study conducted on four 7�8 years old Persian speaking children. The data for analysis was collected using an ultrasound machine in 2018�2019. The stimuli included a range of consonants including/p/,/t/,/f/,/k/and/s/in consonant-vowel sequences, with the vowels/a/and/i/. The measures do not require head stabilization. Statistical analyses were done using Linear mixed models in lmer software package of R version 3.6.2. The results were performed by Chi-squared and Tukey post hoc tests in R. Results: In all of the consonants, the mean of two single curve measures in the context of/i/was greater than the context of/a/. However, there was no significant effect of the vowel context on one measure for the/k/. Also, these measures were significantly different in each of the Persian consonants and they showed consistent patterns across all of the participants (P<0.001). Conclusion: It seems the single curve measures are the valid value of tongue dorsum excursion for Persian speaking children. This study showed that measures of single curves are reliable for distinguish between consonants in vowel contexts and created robust results on lingual coarticulation of the consonants without the use of head stabilization. © 2020 Elsevier B.V

The Effect of two Different Doses of Propofol Infusion on Cardiovascular Responses in Patients Candidate for Nasal Septoplastic Surgery

Background & aim: There is no general consensus on the minimum dose of propofol for maintenance of anesthesia. The purpose of this study was to determine the effect(s) of two different doses of propofol on cardiovascular responses in patients undergoing Septoplasty surgery. Methods: In the present clinical-trial study, fifty-eight patients (15 to 55 years) candidate for nasal Septoplasty were randomly divided into two groups of A (propofol infusion dose 50µg/kg/min) and B (propofol infusion dose 100µg/kg/min). After induction of anesthesia and intubation, propofol infusion was started with two different doses. Systolic, diastolic and mean arterial blood pressures were measured at 0, 2, 5, 10, 15, 20, 30, 45 and 60 minutes after initiation of infusion. The depth of anesthesia during the surgery and wake-up time was evaluated. The data were analyzed by independent sample t-test, Mann-Whitney U test, repeated measure and Freidman. Results: Wake up time in group A and B was (28.71±3.19) and (31.00±5.29) min respectively which no significant differences were observed between the two groups. Changes in heart rate and systolic blood pressure, diastolic and mean arterial at different minutes in each group compared with the other two groups showed no significant difference (p> 0.05). Conclusions: Increasing dose of propofol from 50µ/kg/min to 100µ/kg/min does not affect the depth of anesthesia, cardiovascular responses and wake up time, so a lower dose of propofol infusions is recommended during general anesthesia