Hydrogen bond synthon competition in the stabilization of theophylline cocrystals

CrystEngComm ◽  
2014 ◽  
Vol 16 (22) ◽  
pp. 4753-4765 ◽  
Author(s):  
Bipul Sarma ◽  
Basanta Saikia
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Physical Stability ◽  
High Humidity

In the preparation of theophylline cocrystals, phenol coformers facilitate water assimilation due to their weaker O–H⋯N(imidazole) synthon. The presence of –COOH prevents water incorporation and provides added physical stability at high humidity. This study shows the feasibility of cocrystal design of an API to tune physical properties based on hydrogen bond synthons.

scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

scholarly journals Application of CMC as Thickener on Nanoemulsions Based on Olive Oil: Physical Properties and Stability

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
C. Arancibia ◽  
R. Navarro-Lisboa ◽  
R. N. Zúñiga ◽  
S. Matiacevich
Keyword(s):  
Physical Properties ◽  
Olive Oil ◽  
Flow Behavior ◽  
Average Particle Size ◽  
Physical Stability ◽  
Tween 80 ◽  
Gelling Agent ◽  
Average Particle ◽  
Anionic Charge ◽  
Oil Concentration

Carboxymethyl cellulose (CMC) is a hydrocolloid with surface activity that could act as emulsifiers in oil-in-water emulsions; however the principal role is that it acts as structuring, thickening, or gelling agent in the aqueous phase. This study aims to evaluate the application of CMC as thickener into nanoemulsions based on olive oil and their influence on particle characteristics, flow behavior, and color. Four nanoemulsions with different oil (5% and 15% w/w olive oil) and CMC (0.5% and 0.75% w/w) concentration and two control samples without CMC added were prepared using Tween 80 as emulsifier. All physical properties studied on nanoemulsions were depending on both oil and CMC concentration. In general, z-average particle size varied among 107–121 nm and those samples with 5% oil and CMC were the most polydisperse. The addition of CMC increased anionic charge of nanoemulsions obtaining zeta potential values among −41 and −55 mV. The oil concentration increased both consistency and pseudoplasticity of samples, although samples were more stable to gravitational separation at the highest CMC concentration. Color of nanoemulsions was affected principally by the oil concentration. Finally, the results showed that CMC could be applied in nanoemulsions as thickener increasing their physical stability although modifying their physical properties.

Intermolecular Hydrogen-Bond Networks and Physical Properties of BF4– and TCNQ•– Salts of Three-Fold Symmetric Tris(alkylamino)phenalenyliums

2011 ◽  
Vol 12 (2) ◽  
pp. 804-810 ◽  
Author(s):  
Tsuyoshi Murata ◽  
Eigo Miyazaki ◽  
Takuji Yokoyama ◽  
Kazuhiro Nakasuji ◽  
Yasushi Morita
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Intermolecular Hydrogen Bond ◽  
Hydrogen Bond Networks

scholarly journals EFFECT OF STERILIZATION USING GAMMA RADIATION ON THE PHYSICOCHEMICAL PROPERTIES OF GEL CONTAINING ALOE VERA POWDER

2021 ◽  
pp. 282-285
Author(s):  
ARIF BUDIMAN
Keyword(s):  
Gamma Radiation ◽  
Physicochemical Properties ◽  
Physical Properties ◽  
Acid Concentration ◽  
Malic Acid ◽  
Physical Stability ◽  
Aloe Vera ◽  
Marker Compound ◽  
Before And After

Objective: This study aims to prepare sterile gel containing aloe vera (AV) powder and evaluate its physicochemical properties after sterilization by gamma radiation. Methods: The gel was prepared using carbomer as stabilizer, and sterilized by gamma radiation. The physical stability was evaluated including organoleptic, pH, viscosity and sterilization. Furthermore, malic acid concentration was determined as a marker compound contained in the gel. Results: The gel was successfully prepared containing 20% AV powder and 25% carbomer. The physical properties including organoleptic, pH and viscosity were not significantly changed after sterilization, and also stable even after 28 storage days. Meanwhile, malic acid concentration before and after sterilization were 47.2 mg/ml and 43.9 mg/ml, respectively. This showed the physicochemical properties were not significantly different after sterilization. Conclusion: Gamma radiation is suitable to sterilize gel containing AV powder.

Formulasi Masker Gel Peel Off Arang Aktif Dari Cangkang Kelapa Sawit(Eleis Quinemis Jacq) Sebagai Pembersih Wajah Dengan Basis Polivinil Alkohol (Pva)

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Uce Lestari ◽  
Yokhobet Ade Jesika ◽  
Muhaimin
Keyword(s):  
Polyvinyl Alcohol ◽  
Physical Properties ◽  
Activated Charcoal ◽  
Physical Stability ◽  
Digital Camera ◽  
Added Value ◽  
Irritation Test ◽  
The Face ◽  
Time Test ◽  
Dry Out

Cangkang kelapa sawit adalah salah satu limbah yang dapat diolah menjadi arang aktif. Arang aktif adalah karbon yang telah diaktivasi sehingga karbon memiliki pori-pori dan area permukaan yang besar guna meningkatkan daya serap kotoran pada wajah sebagai pembersih wajah. Tujuan dari penelitian ini adalah mencari alternative aplikasi limbah cangkang kelapa sawit guna memberikan nilai tambah, arang aktif dapat dimanfaatkan sebagai masker pembersih wajah dalam bentuk gel peel off. Untuk membuat masker gel untuk kulit dapat menggunakan Polyvinyl Alcohol (PVA). PVA digunakan karena dapat membentuk lapisan elastis dan kuat ketika kontakdengankulit dan mudah mongering tanpa perlu adanya bahan aditif. Masker gel peel off arang aktif diuji stabilitas fisiknya. Evaluasi sifat fisik yang dilakukan adalah pemeriksaan organoleptik, pemeriksaan homogenitas, pemeriksaan pH, viskositas dan reologi, uji sebaran, uji waktu kering, uji iritasi, uji kesukaan, dan uji kondisional. Hasil penelitian menunjukkan bahwa formula ke-3 memiliki sifat fisik paling ideal dan lebih disukai oleh panelis. Efektivitas masker PVA-arang aktif diamati dengan menggunakan kamera digital yang menunjukkan struktur permukaan kulit lebih halus dan bersih setelah masker diaplikasikan dibandingkan dengan kulit yang tidak menggunakan masker.   Palm shell is one of the waste that can be processed into activated charcoal. Activated charcoal is a carbon that has been treated by activation so that the compound has pores and a very large surface area in order to increase the absorber power to the dirt on the face as a facial cleanser. The purpose of this research is to look for alternative utilization of waste into activated charcoal that can provide added value so it can be formed into a face cleansing mask in the form of peel off gel. To create gel masks made of skin containing such as Polyvinyl Alcohol (PVA). PVA is used because PVA will form an elastic and strong peel off coating to get in contact with the skin well and easily dry out without the help of other materials. Gel mask exfoliated activated charcoal tested its physical stability. Evaluation of physical properties performed is organoleptic examination, homogeneity examination, pH examination, viscosity and rheology, spreading test, dry time test, favorite test irritation test, and test conditional test. The results showed that the 3rd formula has the most ideal physical properties and preffered more by panelists, which then tested the effectiveness in the dirt net. The effectiveness is using a digital camera shows the structure of skin surfaces are smoother and cleaner after the mask was being applied compare to those skin where no mask applied.

scholarly journals FORMULASI SEDIAAN KRIM A/M DENGAN VARIASI KONSENTRASI EKSTRAK ETANOL DAGING BUAH PEPAYA (Carica Papaya) MENGGUNAKAN EMULGATOR TWEEN 80 DAN SPAN 80

Media Farmasi ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 33
Author(s):  
Gita Puspita ◽  
Nining Sugihartini ◽  
Iis Wahyuningsih
Keyword(s):  
Phase Separation ◽  
Physical Properties ◽  
Carica Papaya ◽  
Physical Stability ◽  
Ethanol Extract ◽  
Tween 80 ◽  
Test Results ◽  
Fruit Extract ◽  
Extract Concentration ◽  
Span 80

Papaya (Carica papaya) contains flavonoid and phenolic compounds proven to have sunscreen and antithyrosinase activity. For this reason, there is a need to formulate them in the form of cream preparations. This study analyzes the effect of the ethanol extract concentration of papaya flesh in the form of A / M cream preparations on their physical properties. The extracts were obtained using the maceration method with 70% ethanol solvent in A / M cream preparations and concentrations of 1%, 3%, and 5% through Tween 80 and Span 80 emulgators. Creams were evaluated for physical properties, including pH, adhesion, dispersion, viscosity, and physical stability. The test results showed that an increase in the concentration of ethanol extract led to a decrease in pH (p <0.05), viscosity (p <0.05), adhesion (p <0.05), and an increase in dispersion (p <0.05). Additionally, phase separation occurs at a concentration of 5% papaya fruit extract cream. These results show that variations in the ethanol extract concentration of papaya fruit influence the physical properties of A / M cream.Keywords: Carica papaya; A / M cream; Physical Properties.Pepaya (Carica papaya) mengandung senyawa flavonoid dan fenolik  yang terbukti memiliki aktivitas sebagai tabir surya dan antitirosinase sehingga perlu diformulasikan dalam bentuk sediaan krim. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh konsentrasi ekstrak etanol daging buah papaya dalam bentuk sediaan krim A/M terhadap sifat fisik sediaan. Ekstraksi buah papaya diperoleh dengan metode maserasi dengan pelarut etanol 70% dalam sediaan krim A/M dengan konsentrasi 1% (FI), 3% (F2) Dan 5% (F3). Krim dievaluasi sifat fisik meliputi pH, daya lekat, dan daya sebar, viskositas dan stabilitas fisik. Hasil uji menunjukkan bahwa peningkatan konsentrasi ekstrak etanol buah papaya menyebabkan penurunan pH (p<0.05), viskositas (p<0.05), daya lekat (p<0.05), peningkatan daya sebar (p<0.05). Terjadi pemisahan fase pada konsentrasi 5% krim ekstrak buah papaya. Berdasarkan hasil dapat disimpulkan bahwa variasi konsentrasi ekstrak etanol daging buah papaya memiliki pengaruh terhadap sifat fisik krim A/MKata kunci : Carica papaya; krim A/M; Sifat Fisik

scholarly journals FORMULASI DAN UJI SIFAT FISIK SEDIAAN GEL EKSTRAK ETANOLIK GANGGANG HIJAU (Ulva Lactuca LINN.)

2020 ◽  
Vol 3 (2) ◽  
pp. 271-280
Author(s):  
emelda emelda ◽  
◽  
Azizah Nada Septiawan ◽  
Dinda Ayu Pratiwi
Keyword(s):  
Physical Properties ◽  
Green Algae ◽  
Skin Diseases ◽  
Hydroxypropyl Methylcellulose ◽  
Physical Stability ◽  
Ethanolic Extract ◽  
Ulva Lactuca ◽  
Acceptance Criteria ◽  
Film Layer ◽  
Optimum Formula

One of the skin diseases that are often experienced by people is acne. The bacteria found in acne are P. acnes, S. aureus, and S. epidermidis. The preparation was chosen in this formulation because it is more practical and durable in storage. Gel preparations were chosen because it dry easily, can form a film layer that is easy to wash, and gives a cool feeling to the skin. Physical stability tests need to be carried out to ensure the quality, safety, and usefulness of the gel so that it meets the expected specifications and is stable in storage. This study aims to make a gel formulation and determine the physical properties of green algae Ethanolic extract gel. The optimum gel formula is determined based on variations in the concentration of Hydroxypropyl methylcellulose. The Gel that meets the criteria of homogeneity, consistency, pH , and dispersibility is determined as the optimum formula. The physical stability of the optimum formula was tested by organoleptic, homogeneity, pH test, spreadability test, and viscosity test. The gel that met the acceptance criteria was green algae ethanolic extract gel with a concentration of 3% HPMC so that it was determined as the optimum formula.

scholarly journals Formulasi dan Karakterisasi Sediaan Nanoemulgel Serbuk Lidah Buaya (Aloe Vera L.)

2019 ◽  
Vol 16 (1) ◽  
pp. 28-37
Author(s):  
Teguh Imanto ◽  
Roseh Prasetiawan ◽  
Erindyah Retno Wikantyasning
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Physical Properties ◽  
Physical Stability ◽  
Aloe Vera ◽  
Tween 80 ◽  
Gelling Agent ◽  
Freeze Thaw ◽  
Particle Size Analyzer ◽  
Oil In Water

Aloe vera L. contains antiseptic saponins and anthraquinone complexes as antibacterial. This research was conducted to formulate aloe vera powder into nanoemulgel, characterize and test its physical properties, and to know the effect of gelling agent concentration (carbopol and chitosan) on nanoemulgel. Emulsion type used is oil in water (O / W) with surfactant tween 80 and co-surfactant propylene glycol. Nanoemulsion is characterized by percent of transmittance with UV-Vis spectrophotometer, also potential droplet and zeta size distribution with Particle Size Analyzer. Hydrogels consist of 4 combination formulas of carbopol 0.5%; 1%; 1.5%; 2% and 0.3% chitosan. The formula is tested for physical properties including organoleptic, pH, spreadability, adhesion, viscosity and stability with freeze thaw method. The results showed that the nanoemulsion droplet size was 65.05nm ± 13.49 with zeta potential of -0.1mV and the percent of transmittance above 98%. The result of physical properties of the four formulas shows that the different gelling agent concentration gives different physical properties of viscosity and spreadability. Overall, formula 3 has the best physical properties and physical stability compared to formula 1, 2 and 4.

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