Effect of Material Change on Stirnol Engine: A Combination of NiTiNOL (Shape Memory Alloy) and Gamma Stirling Engine.

Population explosion, industrialization, and urbanization have accelerated energy requirements across the globe. This has led to the human quest to find simple and cost-effective energy solutions. A promising solution is the revival of the Stirling engine with the addition of Shape Memory Alloy NiTiNOL in it. The experimental results reveal that the addition of a NiTiNOL spring at the base plate of the Stirling engine enhances the overall efficiency of the engine, demonstrating some impact of the shape memory alloy toward the performance output of the Stirling engine. The newly modified engine has been named the STIRNOL ENGINE. The comparative study of Stirling and Stirnol engines reveals a minuscule efficiency improvement, yet there is a furtherance that opens a window for future researchers to get a lead and venture into this new field. We are confident that with more complex designs and better Stirling and NiTiNOL combinations, more efficient engines can be invented in the future. This research focuses on changing the material of the base plate of the Stirnol engine and ascertaining its performance differential through the integration of the NiTiNOL spring. A minimum of four types of materials are utilized for experimentation.

Investigation of Thermal Gel Formation of Methylcellulose in Glycols Using DSC and XRD.

Novel compositions of methylcellulose in ethylene, propylene and butylene glycol were investigated for their thermal gel formation. These compositions have previously been found useful for inkjet-printing-based additive manufacturing processes as support materials. Experimental techniques such as viscosity measurements between 20 °C-150 °C-20 °C, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used and the results showed that the gel formation upon cooling is caused by polymer-polymer association. The results also show that, for methylcellulose, propylene glycol is a better solvent than ethylene glycol and butylene glycol. Since no chemical reaction is involved, these gels can be used as support materials for jetting-based additive manufacturing processes.

Development and validation of reverse phase HPLC method for determination of angiotensin receptor blocking agent irbesartan in plasma.

A sensitive, reproducible and modest analytical procedure was developed and validated for evaluation of irbesartan in human plasma. LLE (Liquid-Liquid extraction) of the drug was carried out with acetonitrile (1:1 v/v). Chromatographic separation of irbesartan was conducted by the help of 4.0mm × 25cm column having L1 packing from plasma and mobile phase utilizing HPLC. The mobile phase comprise of phosphate buffer and acetonitrile in a ratio of 67:33 v/v. The flow rate was set at 1ml/minute and the detector at a wavelength of 220 nm. The resolution of irbesartan was well performed from plasma components. This method was validated and demonstrated linearity with a concentration range of 0.1to 6µg/ml of irbesartan in plasma. Intra-day, inter-day accuracy was found 89.33% to 96.37% while intra-day, inter-day precision was found within the limit of 0.02 and 2.15 respectively. The mean recovery of irbesartan was 97.28%. The efficacy of extraction was proved by above-mentioned results. In plasma, the 0.05 and 0.1µg/ml dilutions were exhibited as the LOD and LOQ of irbesartan. Stability studies disclosed that irbesartan showed stability at -20°C storage.

Formulation design, characterization and optimization of cinitapride (1mg) immediate release tablets using direct compression technology.

Cinitapride hydrogen tartarate is relatively a new prokinetic agent that widely prescribed for GERD and epigastric pain. Present study was aimed to develop and optimize cinitapride (1 mg) immediate release (IR) tablet formulation(s) by direct compression using central composite rotatable technique. Overall nine formulations (FC1-FC9) were generated by varying the composition of binder avicel PH 102 (X1) and superdisintegrant crospovidone (X2). The effect of interaction of excipients on hardness (Y1), friability (Y2), disintegration (Y3) and dissolution at 15 min (Y4) were analyzed by RSM plotting. On the basis of physico-chemical evaluation FC3, FC4 and FC6 were found to be the optimized formulations however; FC3 was selected to be the best trial owing to excellent drug release (100.17%) with least friability (0.14%). These IR tablets showed the release pattern similar to the Weibull model with r2 value of 0.978-0.998. The dissimilarity (f1) and similarity indexes (f2) of FC3, FC4, FC6 with the marketed product were estimated to be 2.57 and 76.51, 4.51 and 64.46, 4.32 and 66.78 respectively. Trial optimized formulations were highly stable with the shelf lives of 58-64 months. So, keeping in view the results of present investigation, it is concluded that the technique of manufacturing and optimization is found to be excellent for developing immediate release cinitapride tablets.

Dexibuprofen: Statistical assessment of drug release kinetics and investigative quality perspective.

Healthcare professionals including physicians and pharmacists have been trying since long to come across and work out regarding the issue of generic alternatives, which is highly affected by factors like therapeutic efficacy, cost effectiveness, aesthetic and elegant appearance and implementation of packaging number over the drug product. However, the community pharmacist professionals are also facing difficulty in making decision regarding selection and dispensing the most efficacious brand to the patients. In this regard, the initiation of recent approaches for the development of amenable drug products has led to evolve the concept of generating new avenues for achieving higher patient compliance. Hence, the objective of this study was to evaluate the quality attributes and make comparisons regarding different brands of Dexibuprofen available in market of Karachi, Pakistan. The study is based on evaluation of physical chemical parameters of five different brands. Moreover, a comparative dissolution profile of selected brands of Dexibuprofen was also performed by applying numerous approaches. DEX-1was selected as reference while DEX-2- DEX-5 was selected as test brands. Results of all the selected brands met all the compendial requirements. Interpretation of the entire aforementioned test was evaluated using model independent, model- dependent and one - way ANOVA. The work presented in this study has been designed to provide quality standard products easily accessible in Pakistani market.

Biowaiver studies of newly optimized meloxicam tablets.

In this research work biowaiver studies of newly developed and optimized Meloxicam 7.5mg and 15mg water dispersible formulations were carried out at different dissolution media i.e. 0.1N HCl, phosphate buffer pH 4.5, pH 6.8, and pH 7.5 at 50 rpm. For this purpose reference (MA9 and MB9) and tests (MA2, MA4, MA6, MA7 and MA8 (15 mg) and MB2, MB4, MB6, MB7and MB8 (7.5 mg) formulations were compared. In vitro patterns were analyzed by using model-independent and model-dependent methods. Results indicated that all formulation at pH 0.1N HCl and phosphate buffer pH 4.5 followed Weibull model, while at pH 6.8 and pH 7.5 all formulations followed Hixson-Crowell model. Similarly results of model independent methods demonstrated that all the reference formulations were found to be similar with the tests formulations. Results indicated that Biowaiver could be granted to all the optimized water dispersible meloxicam formulations of both batches, so waiver for bioequivalence study can be allowed.

Development and validation of RP- HPLC method with UV detection to determine and quantify dimenhydrinate in human plasma.

A simple, sensitive and rigorous method for estimation of dimenhydrinate in human plasma was searched and its validation was carried out. LLE (Liquid-Liquid extraction) of analyte with mixture of Hexane and ethyl acetate (1:1 v/v) was carried out for the preparation of Plasma Samples, Chromatographic elution of dimenhydrinate was conducted in human plasma and mobile phase with C-18 bonda Pack column (10µm; 250 × 4.6), using a mobile phase consisting a solution of ammonium bicarbonate in water and methanol at a flow rate of 0.5ml/minute with UV detection at 229 nm. The resolution of dimenhydrinate was well performed from plasma components. This method was validated and exhibited linearity with concentration range of 6 to 380ng/ml of dimenhydrinate in plasma. The Intra day precision was 89.2 to 96.89% and Inter day precision was 88.6% to 93.26%, the average recovery of dimenhydrinate was 97.02%. The efficacy of extraction was proved by above mentioned results. 2ng/ml and 6ng/ml, were appraised as the LOD and LOQ of dimenhydrinate, stability studies disclosed that dimenhydrinate exhibited stability in Plasma after Freeze & thaw cycles and upon -20°C storage, the method was developed well.

Incidence of drug interactions in intensive care units in tertiary care settings: Classification, facts and measures.

Drug-drug interactions (DDIs) are extremely significant concern, particularly in sensitive population including pediatric and geriatric. Propensity for the development of DDIs is high in patients admitted at intensive care units (ICU). This study was conducted to evaluate the DDIs incidence, facts and measures in ICU. From a total of 150 cases studied for ICU patients, with the mean age of 56.37±12.45 years, 55.33% were male and the rest were female 44.66%. The demographic information like age, gender and main diagnosis details of study participants that were extracted from the patients' clinical record. A statistically significant association between the drug interaction and the number of drugs prescribed per prescription was observed (p<0.0001). Concerning the onset of outcome, 52% of DDIs distinguished as delayed onset of effect (past 24 hours) and 35% were categorized as rapid onset (within 24 hours). Despite the facts regarding patient safety and minimizing DIs error, polypharmacy is still frequent in critically ill patients admitted in ICU attributed high risk of adverse reactions due to use of multiple interventions to treat severity of disease condition. Such studies may be used to develop an effective tool for the diagnosis and management of DDIs.

Polyethylene Glycol-3350 (Miralax®)+1.9-L sports drink (Gatorade®)+2 tablets of bisacodyl results in inferior bowel preparation for colonoscopy compared with Polyethylene Glycol-Ascorbic Acid (MoviPrep®).

BACKGROUND/AIMS: Polyethylene glycol (PEG)-3350, approved by Food and Drug Administration (FDA) only for constipation, combined with 1.9 L of sports drink (SD) (GatoradeR) and bisacodyl (B) is commonly used in outpatient practice for bowel preparation due to cited patient satisfaction and tolerability of this specific regimen. We aim to compare PEG-3350 (MiralaxR) with PEG-AA-based (MoviPrepR) in terms of efficacy, patient satisfaction, and the effects of these two regimen on serum electrolytes. MATERIALS AND METHODS: This study is a prospective, single-blinded, block randomized trial comparing single-dose PEG-3350+SD+B to split-dose 2-L PEG-AA in the outpatient endoscopy unit in patients undergoing colonoscopy. Basic metabolic profiles were checked on the day of randomization and on the day of procedure. Patients completed a survey on the day of procedure. Bowel preparation quality was assessed using the Boston Bowel Preparation Scale (BBPS) by two endoscopists and a nurse present during the procedure. RESULTS: We randomized 150 patients (74 PEG-3350+SD+B and 76 PEG-AA). The PEG-AA group had significantly higher BBPS scores in the right colon by Endoscopist 1, Nurse, and Endoscopist 2 (p 0.005, <0.000, 0.001) and in the left and transverse colon by Nurse and Endoscopist 2 (p 0.004, 0.26, 0.000, 0.006). There was no statistically significant difference in patient satisfaction or change in serum electrolytes between the two groups. CONCLUSION: Use of single-dose PEG-3350+SD+B results in inferior bowel preparation for colonoscopy compared with split-dose PEGAA and does not provide any advantage in regards to patient satisfaction. We therefore recommend discontinuing the use of PEG 3350 for bowel preparation.

Evaluation of Potential Drug-Drug Interactions with Antidepressants in Two Tertiary Care Hospitals.

BACKGROUND: Limited resources of healthcare system and high use of antidepressants have raised some serious concerns regarding proper surveillance system of prescribed medicines. Not much literature is available from Pakistan regarding the potential drug-drug interactions (pDDIs) associated with antidepressants. OBJECTIVE: The objective of this study was to assess the frequency of pDDIs associated with antidepressants, their severity, significance and their association with patient characteristics. MATERIALS AND METHODS: A prospective, observational study was conducted in two major hospitals of Karachi for the period of three months. Patient profiles, medication charts, and physician notes were thoroughly reviewed to gather all the relevant information. Inclusion and exclusion criteria were set prior to data collection. The collected data was then analysed using Micromedex Drug-REAX System. Descriptive and binomial logistic regression analysis was used to express results. RESULTS: Of 245 prescriptions reviewed, 141 prescriptions had at least one pDDI (57.5%). A total of 181 pDDIs were identified in prescription containing antidepressant. The ratio of pDDI per prescriptions was 0.78. 42.5% interactions were moderate in severity, 30% of interactions were rapid in onset, and 43% were considered as significant interactions. Polypharmacy (OR=3.41, p< 0.001) and presence of chronic problems (OR=2.14, p=0.002) were significantly associated with the occurrence of pDDIs. Citalopram and diclofenac (11.6%) was commonly prescribed interacting pair in this study. CONCLUSION: The findings of this study recorded high frequency of antidepressants associated pDDIs. Our results confirm the significant association of polypharmacy with the occurrence of pDDIs with antidepressants. Future studies are warranted to establish these results by including hospitals in different parts of the country.