Crystal Pharmatech

Princeton, NJ, United States

Crystal Pharmatech

Princeton, NJ, United States
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Wang L.,CAS Suzhou Institute of Nano Technology and Nano Bionics | Zhao Y.,Beijing Institute of Pharmacology and Toxicology | Zhang Z.,CAS Wuhan Institute of Physics and Mathematics | Wang J.,Crystal Pharmatech | And 4 more authors.
Journal of Molecular Structure | Year: 2017

Acyclovir is a commonly used antiviral drug while its solubility is far from satisfied. It was reported that 1:1 acyclovir-maleic acid salt (ACV-MAL) possesses much higher maximum apparent solubility. In this contribution, a new crystal structure of ACV-MAL was solved at room temperature. This new crystal structure and previously reported structure at low temperature can transform to each other via a reversible solid phase transformation, which has been confirmed by single-crystal X-ray diffraction, solid state NMR and cycling differential scanning calorimetry tests. The phase change temperature is ca. 283–293 K (10–20 °C), which is slightly lower than room temperature (298 ± 2 K/25 ± 2 °C), but is in the range of ambient temperature. This kind of near room temperature phase transformation is less concerned and tends to be neglected. This case report reminds that more attention should be paid to the polymorphism of pharmaceuticals at such temperature range due to its fundamental and practical significance. © 2016 Elsevier B.V.

Newman A.,Crystal Pharmatech | Nagapudi K.,Genentech | Wenslow R.,Crystal Pharmatech
Therapeutic Delivery | Year: 2015

Amorphous solid dispersions (ASDs) are being used with increasing frequency for poorly soluble pharmaceutical compounds in development. These systems consist of an amorphous active pharmaceutical ingredient stabilized by a polymer to produce a system with improved physical and solution stability. ASDs are commonly considered as a means of improving the apparent solubility of an active pharmaceutical ingredient. This review will discuss methods of preparation and characterization of ASDs with an emphasis on understanding and predicting stability. Theoretical understanding of supersaturation and predicting in vivo performance will be stressed. Additionally, a summary of preclinical and clinical development efforts will be presented to give the reader an understanding of risks and key pitfalls when developing an ASD. © 2015 Future Science Ltd

Wang L.,CAS Suzhou Institute of Nano Technology and Nano Bionics | Wang L.,Soochow University of China | Luo M.,Crystal Pharmatech | Li J.,CAS Suzhou Institute of Nano Technology and Nano Bionics | And 3 more authors.
Crystal Growth and Design | Year: 2015

A novel pharmaceutical cocrystal (THPAH12) of Theophylline (THP) was obtained with an artificial sweetener, Acesulfame (AH), in a molar ratio of 1:2. Solid state NMR spectra of the cocrystal indicate that the two AH molecules exist as keto and enol tautomers, which is further confirmed by the refined crystal structure. THPAH12 is the first keto form AH containing cocrystal. This highlights the fact that not only OH of enol form of AH, but also the NH-C - O group of the keto form of AH should be considered when designing new pharmaceutical cocrystals via the supramolecular synthon approach. Compared with pure THP, THPAH12 possesses enhanced solubility and hydration stability, which highlight its potential for further pharmaceutical applications. © 2015 American Chemical Society.

Shen M.,Soochow University of China | Shen M.,Zhejiang University | Pan P.,Soochow University of China | Pan P.,Zhejiang University | And 5 more authors.
Drug Discovery Today | Year: 2015

Farnesyltransferase (FTase) and geranylgeranyltransferase type I (GGTase-I) have crucial roles in the post-translational modifications of Ras proteins and, therefore, they are promising therapeutic targets for the treatment of various Ras-induced cancers and several other kinds of diseases. In this review, we provide an overview of the structures and biological functions of FTase and GGTase-I. Then, we summarize the typical inhibitors of FTase and GGTase-I, and highlight the drug candidates in clinical trials. In addition, we survey some recent advances in computer-aided drug design (CADD) and molecular modeling studies of FTase and GGTase-I. © 2014 Elsevier Ltd.

Wang L.,CAS Suzhou Institute of Nano Technology and Nano Bionics | Wang L.,Soochow University of China | Wen X.,Crystal Pharmatech | Li P.,CAS Suzhou Institute of Nano Technology and Nano Bionics | And 4 more authors.
CrystEngComm | Year: 2014

5-Fluorocytosine (FC), a widely used antifungal drug, has poor physical stability under different relative humidity (RH) conditions, which may trigger serious challenges during its drug product development. In this contribution, a conjugate acid-base (CAB) cocrystal and a salt hydrate of FC were obtained with an artificial sweetener, acesulfame (AH), in molar ratios of 2:1 (FCAH21) and 1:1 (FCAH11), respectively. The resulting products were characterized by a variety of analytical methods, including single-crystal and powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), and dynamic vapor sorption (DVS). 13C and 15N solid-state NMR spectra provide solid evidence for the CAB cocrystal/salt formation. At room temperature, moisture sorption data show that the new forms are nonhygroscopic/slightly hygroscopic and resistant to FC hydrate formation under high RH conditions (>80%). FCAH21 has a higher FC content and presents more favorable thermal stability than FCAH11, which make it more attractive for further pharmaceutical application. This journal is © the Partner Organisations 2014.

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