Isolation and solid-state characteristics of a new crystal form of indomethacin.

A new polymorphic crystal form of indomethacin was precipitated from an aqueous solution of indomethacin and beta-cyclodextrin by titration with a 0.5 N HCl aqueous solution. Three polymorphs (alpha, beta, and gamma forms) and a new crystal form were differentiated with thermal analysis, infrared spectroscopy, powder X-ray diffractometry, thin-layer chromatography, elemental analysis, and Fourier transform infrared (FTIR) spectroscopy with a newly developed FTIR microscope equipped with a thermal analyzer. The new crystal polymorph of indomethacin exhibited endo- and exothermic peaks near 102.8 and 104.1 degrees C, respectively, because of phase transitions without weight loss, followed by two additional endothermic peaks at 151 and 158.9 degrees C, because of fusion. The differential scanning calorimetry-FTIR system can be used to examine the correlation between structural change of C = O stretching bands of this new polymorph and its thermal response. The new crystal form contained some gamma-form crystals, determined with an FTIR microscope equipped with a mapping option. Solid-state carbon-13 nuclear magnetic resonance spectra of the polymorphs of indomethacin were also examined.     

头孢唑林钠水合物新晶体及其理化特性的研究

头孢唑林钠(cefazolin sodium)是目前临床中最常用的半合成头孢菌素,其与水分子等作用可形成α型(含5分子结晶水)、β型(含3/2分子结晶水)和γ型(含1分子结晶乙醇)等晶体[1],但目前仅有少量文献对其晶体结构进行探讨[2～4].     

Structural characteristics and crystal polymorphism of three local anaesthetic bases crystal polymorphism of local anaesthetic drugs: part VII

Benzocaine (BZC), butambene (BTN) and isobutambene (BTI) are basic local anaesthetic agents of the ester type, preferentially used for surgery and dental procedures. The compounds, official in the USP (BZC and BTN) and Ph. Eur. (BZC), were each found to exist in two polymorphic crystal forms and their solid state characteristics have been determined by thermomicroscopy, differential scanning calorimetry (DSC), FTIR-, FT-Raman-spectroscopy as well as X-ray powder diffractometry. This work further emphasizes the comparison of solid state characteristics of three compounds with closely related structural features on molecular level, leading to opportunities for the investigation of structure-property relationships. Mod. I0 is the particular thermodynamically stable form at room temperature in all of the three systems. This form is present in commercial products and can be crystallized from solvents at room conditions. Mod. II can be obtained by annealing the supercooled melt or fast cooling of a saturated solution, respectively. The endothermic transformation of mod. II to mod. I0 upon heating confirms that mod. I0 is thermodynamically stable at ambient conditions (heat of transition rule) whereas mod. II is enantiotropically related to mod. I0, i.e. is metastable at temperatures above the transition temperature. The metastable forms show different kinetic stabilities at room temperature.     

新型口服固体速释制剂———口腔速崩片

目的：介绍目前口腔速崩片崩解剂的特性、制备工艺、特点,为国内口崩片的设计和制备提供参考及思路。方法：概述了近十几年来,国外选用的崩解剂和改善口感的方法及其应用概况。结果：通过对口崩片崩解剂特性的了解,为口崩制剂的处方设计提供依据,开阔思路。结论：对口崩制剂的深入研究有助于开发有价值的老年人和其他特殊病人用药。     

Structural characteristics of the aging skin: a review

As life expectancy in industrialized countries increases, appropriate care of elderly skin looms as a dermatologic priority. Skin aging is a complex, multifactorial process whose baseline rate is genetically determined but that may be accelerated by environmental, mechanical, or socioeconomic factors. The intrinsic structural changes that occur with the aging of the skin increase skin fragility, decrease the ability of the skin to heal, increase risk for toxicological injuries, promote the development of various cutaneous disorders, and produce aesthetically undesirable effects like wrinkling and uneven pigmentation. As aged patients represent a larger segment of the population, increased attention to the problems of the aged skin, both cosmetic and beyond, will be necessary and should build on currently successful interventions to improve their quality of life.     

The influence of crystal form on the radial stress transmission characteristics of pharmaceutical materials.

Various crystal forms of sulphathiazole, barbitone and aspirin were compressed in a single-punch tablet machine instrumented to monitor axially applied and radially transmitted forces, and upper punch movement. The changes in radial stress during the compression cycle depended upon the polymorphic form of the compressed material. The results were rationalized in terms of the degree of plastic flow/crushing that occurred with each material, and the degree to which the final compact underwent elastic compression. It is postulated that the reduction in the transition temperature of polymorphic forms of sulphathiazole and barbitone and the polymorphic transition of sulphathiazole Form II was due to the production of dislocations in the crystal and the crystals at crystal boundaries formed in the compressed materials.     

Enzymic and molecular characteristics of a new form of monoamine oxidase, distinct from form-A and form-B

The present study was undertaken to clarify the enzymic and molecular properties of monoamine oxidase (MAO) in carp brain. In particular, its sensitivities to selective MAO inhibitors, kinetic properties and molecular weight were compared with those of the enzyme in carp liver. The selective and potent MAO-A and MAO-B inhibitors FLA 788(+), FLA 336(+), MD 780236 and benzylcyanide caused dose-dependent inhibitions of MAO activity in both carp brain and liver; the inhibition curves were all single-sigmoidal, and the degrees of inhibition of the activities towards 5-hydroxytryptamine (5-HT, selective MAO-A substrate), tyramine (substrate for both forms of MAO) and beta-phenylethylamine (PEA, selective MAO-B substrate) were similar. This was also the case for inhibition of activity in carp brain by the irreversible and selective MAO-A and MAO-B inhibitors clorgyline and I-deprenyl, indicating the presence in both preparations of a single MAO which differs from either form of MAO. Studies on the substrate specificities and Km values for these three substrates and the inhibitory effects of some compounds suggested that the enzymic characters of MAO in carp preparations were similar and that these enzymes might be FAD-containing enzymes, like MAO in various mammals. By labelling the preparations with radioactive pargyline and then subjecting them to sodium dodecyl sulfate electrophoresis, the apparent molecular weights of carp brain and liver MAO were estimated as 60,000 daltons. The same value was also obtained for rat brain and liver mitochondrial MAO-B. These results indicate that by the present definitions of MAO-A and MAO-B, MAO in carp brain and liver is similar to, but distinct from, both these forms of MAO.     

Physico-chemical characterisation and intrinsic dissolution studies of a new hydrate form of diclofenac sodium: comparison with anhydrous form

Diclofenac sodium is a non-steroidal anti-inflammatory drug widely used in painful and inflammatory diseases. In standard conditions, by exposure to relative humidity even below 60% at 25 °C, the anhydrous form DS gives rise to a hydrate species DSH, a tetrahydrate form different from that obtained by crystallisation from water and previously described. The method of preparation and the physico-chemical properties of the hydrate form were investigated. Data from FTIR spectroscopy, X-ray powder diffraction and thermal analysis were used for the identification and the characterisation of DSH. DS and DSH were easily differentiated by their IR spectra, X-ray patterns and thermal behaviour. DSH stability was followed at room temperature over a period of 1 year and under different conditions of temperature to verify the tendency to solid–solid transition and to study its existence range. Solubility and intrinsic dissolution studies were performed to compare the physico-chemical properties of DS and DSH. Differences in solubility and intrinsic dissolution rates were pointed out: these studies showed that DS dissolved faster than DSH. Storage under uncontrolled environmental conditions or contact with water vapour during manufacturing process could thus influence the performance of the final dosage form.     

Myo-inositol in a new pharmaceutical form: a step forward to a broader clinical use

Objective: Dose-dependent side effects related to myo-inositol (MI) oral administration represent a significant shortcoming for its clinical use. Aiming to search for a pharmaceutical form able to be better absorbed, the pharmacokinetic (PK) profile of the new manufactured MI soft gelatin capsule form was evaluated and compared with the commercially available MI powder.

Research design and methods: A single-dose relative trial, consisting of four phases, was performed on 20 healthy volunteers who received different doses of MI powder and MI soft gelatin capsules. PK profiles related to the two pharmaceutical forms were obtained by analysis of MI plasma concentration, and the respective MI bioavailability was compared.

Results: The administration of MI powder and MI soft gelatin capsules resulted in a different bioavailability. MI soft gelatin capsule form showed similar PK parameters compared with three times higher doses of MI in powder form.

Conclusions: MI soft gelatin capsules displayed an improved bioavailability, allowing to substantially reduce the administered dose and to minimize the dose-dependent side effects. Considering the number of conditions in which MI supplementation is recommended, this evidence could support a broader use of MI in clinical practice.     

Properties and stability of a liquid crystal form of cyclosporine-the first reported naturally occurring peptide that exists as a thermotropic liquid crystal

A new solid-state form of cyclosporine produced by spray-drying exhibited characteristics consistent with a liquid crystal. No sharp diffraction peaks were observed by powder X-ray diffraction; however, analysis by both small-angle X-ray diffraction (SAXR) and microscopic under polarized light (PLM) confirmed the existence of two-dimensional ordered liquid crystal. Hot stage microscopy revealed a solid-to-liquid transition, in the range of 118 to 125 degrees C. Moreover, the solid-to-liquid transition showed frequency dependence by dielectric analysis (DEA), and was coincidental with a stepwise heat capacity change measured by differential scanning Calorimetry (DSC). The two-dimensional order was maintained above the solid-to-liquid transition temperature indicated by low-angle diffraction by SAXR and birefringence by PLM. However, birefringence was lost at temperatures above 170 degrees C, indicating the conversion of the liquid crystal into an isotropic liquid. In situ annealing experiments, by DSC, revealed the presence of an endotherm, unexplained by either a phase transition or solvent loss, and it is believed to be the result of a structural rearrangement that has no impact on the macroscopic properties of the material. Spray-dried cyclosporine at room temperature is therefore a frozen thermotropic liquid crystal due to the presence of two-dimensional order and the lack of substantial residual solvent. This is, to our knowledge, the first report of the existence of a thermotropic liquid crystal of a naturally occurring peptide.     

Olanzapine (Zyprexa):characteristics of a new antipsychotic

Olanzapine is a thienobenzodiszepine antipsychotic,which exerts broad-spectrum receptor antagonism in the central nervous system.It demonstrates regionally selective dopamine antagonist activity as measured with the depolarisation block model and fos activation paradigm. Early in vivo imaging studies suggest a relatively low D2 occupancy in th striatum (69%) with a higher 5-HT2 occupancy in the cortex (84%) of 10 mg.Its pharmaco-kinetics are dose-proportional; Tmax is 5 h and the elimination half-life is 31 h (range:21-54 h). Efficacy studies show equivalent antipsychotic efficacy to haloperidol with the possibility of superior efficacy on negative symptoms and depression. Motor side-effects are minimal with mild akathisia emerging at the highest doses; non-motor side-effects are also minimal. Olanzapine is a highly effective antipsychotic drug with minimal side-effects. It will be an important new drug for treating schizophrenia.     

Polymorphism of Alprazolam (Xanax): a review of its crystalline phases and identification, crystallographic characterization, and crystal structure of a new polymorph (form III)

A new polymorphic form of Alprazolam (Xanax), 8-chloro-1-methyl-6-phenyl-4H-[1,2,4]triazolo-[4,3-alpha][1,4]benzodiazepine, C(17)H(13)ClN(4), has been investigated by means of X-ray powder diffraction (XRPD), single crystal X-ray diffraction, and differential scanning calorimetry (DSC). This polymorphic form (form III) was obtained during DSC experiments after the exothermic recrystallization of the melt of form I. The crystal unit cell dimensions for form III were determined from diffractometer methods. The monoclinic unit cell found for this polymorph using XRPD after indexing the powder diffractogram was confirmed by the cell parameters obtained from single crystal X-ray diffractometry on a crystal isolated from the DSC pans. The single crystal unit cell parameters are: a = 28.929(9), b = 13.844(8), c = 7.361(3) angstroms, beta = 92.82(3) degrees , V = 2944(2) angstroms(3), Z = 8, space group P2(1) (No.4), Dx = 1.393 Mg/m(3). The structure obtained from single crystal X-ray diffraction was used as initial model for Rietveld refinement on the powder diffraction data of form III. The temperature phase transformations of alprazolam were also studied using high temperature XRPD. A review of the different phases available in the Powder Diffraction File (PDF) database for this drug is described bringing some clarification and corrections.     

Physicochemical properties of oxamniquine indicate a new polymorphic form.

New dissolution rate, chemical stability and thermal analysis data are reported for an anti-schistosomal drug, oxamniquine. A slow dissolution rate (40-70% in 1 h) was found, which may contribute to its erratic clinical response. The drug was found to be chemically stable in water for at least 21 days at 37 degrees C. Dissolution rate and thermal analysis evidence is presented for a previously unreported polymorph (Form III). This form appears to be intermediate in physical stability between the known Forms I and II.     

Bioavailability of phenytoin in dogs: effect of crystal form and particle size.

Significant differences in bioavailability were observed in dogs when phenytoin crystals of different particle size were administered. No significant differences in bioavailability were observed when different crystal forms were compared.     

新型口服固体速释制剂—口腔崩解片的研究概况

新型口服固体速释制剂-口腔崩解片以其在口腔内迅速崩解、起效快、生物利用度高、服用方便等特点受到了越来越多的药学工作者的关注,而且在很大程度上解决了老人、儿童等其他吞咽困难的病人服药难的问题.本文主要介绍了口腔崩解片的速崩机理、几种制备工艺及辅料,质量控制方法关键在于崩解时限和溶出度的检查,最后介绍了国内外已经上市的口腔崩解片的若干品种.