Preparation and in vivo and in vitro evaluation of Pulsatilla Saponin D Solid Dispersions / 中草药

Objective: To prepare the solid dispersion of Pulsatilla saponin D (PSD-SD) and evalution its in vivo and in vitro drug release behavior. Methods: The PSD-SD was prepared by solvent method. Three carriers were used in the PSD-SD. Infrared spectroscopy (IR), differential thermal analysis (DSC), and X-ray diffraction (XRD) were used to determine the PSD-SD. Dissolution rates and pharmacokinetic parameters were evaluated in vitro and in vivo characteristics of the PSD-SD. Results: When the PEG 6000 was used as carrier, the solubility of PSD was increased from 2.39 to 7.06 mg/mL, and the cumulative release rate of PSD reached 90% in 60 min, and the bioavailability of PSD was increased to 2.24 times. Conclusion: The solid dispersion prepared PSD can increase the solubility, dissolution rate, and bioavailability.

Comparative Studies on Dissolution and Bioavailability of Tamoxifen Citrate Loaded Binary and Ternary Solid Dispersions.

Aims: This study focused on comparing binary and ternary solid dispersions (SD's) of water-insoluble Tamoxifen citrate (TMC) regarding drug dissolution and oral bioavailability. Basically, the enhanced dissolution of this drug by water-soluble polymer has not yet been reported in literature. Study Design: In vitro and In-vivo characterization of Tamoxifen citrate loaded binary and ternary solid dispersion systems. Place and Duration of Study: Department of Pharmaceutics and Industrial Pharmacy, Helwan University, Cairo, Egypt between June 2012 and June 2013. Methodology: Amorphous SD's of TMC with two hydrophilic polymers, polyethylene glycol 6000 (PEG 6000) and Methyl cellulose (MC), were prepared by melting method. Binary SD's of TMC with PEG of different weight ratios were prepared. MC was used as third component to prepare ternary SD's. Physicochemical properties of SD's were characterized by FTIR, DSC, and In-vitro drug release in comparison with physical mixtures and the drug alone. Oral bioavailability of the optimized SD formula was compared with that of free TMC in rats. Results: Infrared spectroscopic studies suggested no interaction between TMC and polymers rather than H-bond formation. A remarkably improved dissolution of drug from the ternary solid dispersion systems when compared to the binary solid dispersion systems was detected. On the basis of % dissolution efficiency (% DE), the SD composed of PEG: TMC: MC in a ratio 4:1:2 w/w/w was selected as the optimized SD. The in-vivo studies showed extremely significant higher values of Cmax (P<.05), AUC0-24 (P<.05) and significantly (P<.05) lower values of Tmax exhibited by SD compared with free TMC. Conclusion: Highly enhanced TMC dissolution and bioavailability exhibited by PEG: TMC: MC ternary solid dispersion in a weight ratio 4:1:2 were promising to improve the therapeutic potential of TMC.

Influences of Polyethylene Glycol6000 on the Solubility of m-Nisoldipine / 医药导报

Objective To investigate the influences of polyethylene glycol on the solubility and in vitro dissolution of m-nisoldipine,which could provide guidance for chosing formulations of m-nisoldipine. Methods Solid dispersions of m-nisoldipine were prepared by solvent-melting method with polyethylene glycol6000 matrix. DSC and XRD spectroscopy were applied to identify the solid dispersions. The solubility and in vitro dissolution were detected by UV spectroscopy. Results The DSC and XRD map were different from the crude drug and their physical mixtures. The dissolution rates(13,15,17) were faster(35. 31%,38. 71%,41. 48%) than that of the crude drug(26. 80%),and the dissolution rates of the solid dispersions in the same ratio were higher than the physical mixtures. Conclusion DSC analysis indicated that eutectic compounds were produced by the m-nisoldipine and polyethylene glycol,in which polyethylene glycol6000 acts as a carrier. The solubility and in vitro dissolution of m-nisoldipine can be increased.

Effects of PEG-6000 stress on tanshinones accumulation in hairy roots of Salvia miltiorrhiza / 中草药

Objective: To study the effects of polyethylene glycol-6000 (PEG-6000) stress on the accumulation of tanshinones in hairy roots of Salvia miltiorrhiza. Methods: Agrobacterium rhizogenes ATCC15834 was used to induce the hairy roots of S. miltiorrhiza. After 20 d suspension culture, the PEG-6000 (1.2%, 2.0%, 5.5%, and 10%, respectively) was added into the suspension cultures and at the same time, the contents of tanshinones (including tanshinone I, cryptotanshinone, dihydrotanshinon I, and tanshinone IIA) were quantified by HPLC on day 7. Results: The growth of the hairy roots of S. miltiorrhiza was inhibited by PEG-6000. After PEG-6000 (1.2%, 2.0%, 5.5%, and 10%) treatment, the dry weights of the hairy roots of S. miltiorrhiza were reduced to 75.1%, 83.0%, 76.2%, and 76.1% of the control group, respectively. Addition of PEG-6000 at different levels could significantly increase the yields of four tanshinones in the hairy roots of S. miltiorrhiza. The yields of tanshinone I, cryptotanshinone, dihydrotanshinon I, and tanshinone IIA were significantly increased by 2.0%-5.5%, 1.2%, 2.0%, and 5.5% PEG-6000, respectively. And the tanshinone IIA increased most. Conclusion: PEG-6000 could stimulate the accumulation of tanshinones in the hairy roots of S. miltiorrhiza.

Physicochemical characterization and solubility enhancement studies of allopurinol solid dispersions / Caracterização físico-química e estudos de solubilidade de melhoria de dispersões sólidas de alopurinol

Allopurinol is a commonly used drug in the treatment of chronic gout or hyperuricaemia associated with treatment of diuretic conditions. One of the major problems with the drug is that it is practically insoluble in water, which results in poor bioavailability after oral administration. In the present study, solid dispersions of allopurinol were prepared by solvent evaporation, kneading method, co-precipitation method, co-grinding method and closed melting methods to increase its water solubility. Hydrophilic carriers such as polyvinylpyrrolidone, polyethylene glycol 6000 were used in the ratio of 1:1, 1:2 and 1:4 (drug to carrier ratio). The aqueous solubility of allopurinol was favored by the presence of both polymers. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, powder X-ray diffraction, UV and Fourier Transform Infrared spectroscopy. Solid state characterizations indicated that allopurinol was present as an amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure allopurinol, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. Solid dispersion prepared with polyvinylpyrrolidone showed highest improvement in wettability and dissolution rate of allopurinol. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer-Peppas model and the drug release kinetics primarily as Non-Fickian diffusion. Therefore, the present study showed that polyvinylpyrrolidone and polyethylene glycol 6000 have a significant solubilizing effect on allopurinol.

Alopurinol é fármaco comumente utilizado no tratamento de gota crônica ou hiperuricemia associada com o tratamento em condições diuréticas. Um dos maiores problemas com o fármaco é que este é praticamente insolúvel em água, o que resulta em baixa biodisponibilidade na administração oral. No presente estudo, dispersões sólidas de alopurinol foram preparadas pela evaporação do solvente, pelos métodos de amassamento, de coprecipitação, de comoagem e fusão fechada para aumentar sua solubilidade em água. Transportadores hidrofílicos, como polivinilpirrolidona, polietilenoglicol 6000 foram utilizados nas proporções de 1:1. 1:2 e 1:4 (fármaco: transportador). A solubilidade aquosa do alopurinol foi favorecida pela presença de ambos os polímeros. Estas novas formulações forma caracterizadas no estado líquido pelos estudos de solubilidade de fase e no estado sólido pela calorimetria diferencial de varredura, difração de Raio-X, espectroscopia de UV e de IV com transformada de Fourier. As caracterizações do estado sólido indicaram que o alopurinol estava presente como material amorfo e embebido em matriz polimérica. Ao contrário da velocidade de dissolução lenta do alopurinol puro, a dispersão do fármaco nos polímeros aumentou consideravelmente a taxa de dissolução. A dispersão sólida preparada com polivinilpirrolidona mostrou as maiores melhorias na molhabilidade e taxa de dissolução do alopurinol. A modelagem matemática dos dados da dissolução in vitro indicou o melhor ajuste ao modelo de Korsemeyer-Peppas e a cinética de liberação do fármaco primariamente como difusão não-Fickiana. Assim, o presente estudo mostrou que a polivinilpirrolidona e o polietilenoglicol 6000 têm efeito significativo na solubilização do alopurinol.

Characterization of gliclazide-polyethylene glycol solid dispersion and its effect on dissolution / Caracterização de gliclazida polietileno-glicol dispersão sólida eo seu efeito sobre a dissolução

The present study was initiated with the objective of studying the in vitro dissolution behavior of gliclazide from its solid dispersion with polyethylene glycol 6000. In this work, a solid dispersion of gliclazide with polyethylene glycol was prepared by the fusion method. In vitro dissolution study of gliclazide, its physical mixture and solid dispersion were carried out to demonstrate the effect of PEG 6000. Analytical techniques of FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry were used to characterize the drug in the physical mixtures and solid dispersions. The dissolution studies of solid dispersion and physical mixture showed greater improvement compared to that of the pure drug. The mechanisms for increased dissolution rate may include reduction of crystallite size, a solubilization effect of the carrier, absence of aggregation of drug crystallites, improved wettability and dispersbility of the drug from the dispersion, dissolution of the drug in the hydrophilic carrier or conversion of drug to an amorphous state. The FT-IR spectra suggested that there was no interaction between gliclazide and PEG 6000 when prepared as a solid dispersion. DSC and XRD study indicated that the drug was converted in the amorphous form.

O presente trabalho foi realizado com o objetivo de estudar o comportamento in vitro da dissolução da gliclazida a partir da sua dispersão sólida com polietileno glicol 6000. Neste trabalho, as dispersões sólidas de gliclazida com polietileno glicol foram preparadas pelo método de fusão. Os estudo de dissolução in vitro da gliclazida, na mistura física e nas dispersões sólidas foram realizados para demonstrar o efeito de PEG 6000. Técnicas analíticas como espectroscopia FT-IR, calorimetria diferencial de varredura e difração de raios-X foram empregadas para caracterizar o fármaco nas misturas físicas e nas dispersoes sólidas. Os estudos de dissolução demonstraram maior melhoria. Os mecanismos para aumentar a velocidade de dissolução podem incluir a redução do tamanho dos cristais, a solubilização do carreador, a ausência de agregação dos cristais do fármaco, a melhoria da molhabilidade e dispersibilidade do fármaco a partir da dispersão, a dissolução do fármaco no carreador hidrofílico ou conversão da forma cristalina do fármaco para estado amorfo. Os espectros de FT-IR sugeriram que não houve interação entre gliclazide PEG 6000 e na sua combinação. Os estudos de DSC e DRX indicaram que o fármaco foi convertido para a forma amorfa.