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At least 829 records · Page 46Linked to original sources
PubMed1998

2-(Dimethylamino)ethyl methacrylate based (co)polymers as gene transfer agents.

Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) is a water-soluble cationic polymer, which is able to bind to DNA by electrostatic interactions. At a polymer/plasmid ratio above 2 (w/w) positively charged complexes were formed with a size around 0.2 microm. The transfection efficiency of polymer/plasmid complexes was evaluated in cell culture (COS-7 and OVCAR-3 cells) using a pCMV-lacZ plasmid, encoding for beta-galactosidase, as a reporter gene. The optimal transfection efficiency was found at a PDMAEMA/plasmid ratio of 3-5 (w/w). Under these conditions 3-6% of the cells were actually transfected. Like other cationic polymers, PDMAEMA is slightly cytotoxic. This activity was partially masked by complexing the polymer with DNA. A pronounced effect of the molecular weight of the polymer on the transfection efficiency was observed. An increasing molecular weight resulted in an increasing number of transfected cells. Dynamic light scattering experiments showed that high molecular weight polymers (Mw>300 kDa) were able to condense DNA effectively (particle size 0.15-0.20 microm). In contrast, when plasmid was incubated with low molecular weight PDMAEMA, large complexes were formed (size 0.5-1.0 microm). Copolymers of DMAEMA with methyl methacrylate (MMA), ethoxytriethylene glycol methacrylate (triEGMA) or N-vinyl-pyrrolidone (NVP) also acted as transfection agents. A copolymer with 20 mol % of MMA showed a reduced transfection efficiency and a substantial increased cytotoxicity compared with a homopolymer of the same molecular weight. A copolymer with triEGMA (48 mol %) showed both a reduced transfection efficiency and a reduced cytotoxicity, whereas a copolymer with NVP (54 mol %) showed an increased transfection efficiency and a decreased cytotoxicity as compared to a DMAEMA homopolymer.

Animals↗
PubMed1999

Influence of formulation parameters on the characteristics of poly(D, L-lactide-co-glycolide) microspheres containing poly(L-lysine) complexed plasmid DNA.

This study describes the influence of polymer type, surfactant type/concentration, and target drug loading on the particle size, plasmid DNA (pDNA) structure, drug loading efficiency, in vitro release, and protection from DNase I degradation of poly(D, L-lactide-co-glycolide) (PLGA) microspheres containing poly(L-lysine) (PLL) complexed pDNA. PLGA microspheres containing pDNA-PLL were prepared using the water-in-oil-in-water (w-o-w) technique with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) as surfactants in the external aqueous phase. A complex ratio of 1:0.33 (pDNA-PLL, w/w) enhanced the stability of pDNA during microsphere preparation. Higher pDNA-PLL loading efficiency (46.2%) and supercoiled structure (64.9%) of pDNA were obtained from hydrophobic PLGA (M(w) 31000) microspheres compared with hydrophilic PLGA or low-molecular-weight PLGA microspheres. The particle size decreased from 6.6 to 2.2 microm when the concentration of PVA was increased from 1 to 7%. At the same concentration of surfactant, PVA stabilized microspheres showed higher pDNA-PLL loading efficiency (46.2%) than PVP stabilized microspheres (24.1%). Encapsulated pDNA in PLGA microspheres was protected from enzymatic degradation and maintained in the supercoiled form. The pDNA-PLL microspheres showed in vitro release of 95.9 and 84.9% within 38 days from the low-molecular-weight PLGA and hydrophilic PLGA microspheres, respectively, compared to 54.2% release from the hydrophobic, higher-molecular-weight PLGA microspheres. The results suggest loading and release of pDNA-PLL complex can be influenced by surfactant concentration and polymer type.

DNA Adducts↗
PubMed1998

Metadoxine accelerates fatty liver recovery in alcoholic patients: results of a randomized double-blind, placebo-control trial. Spanish Group for the Study of Alcoholic Fatty Liver.

BACKGROUND/AIMS: Our aim was to investigate the effectiveness of metadoxine (pyridoxol L, 2 pyrrolidone-5-carboxylate) in the treatment of alcoholic fatty liver. METHODS: A double-blind randomized multicenter trial involving 136 chronic active alcoholic patients diagnosed with fatty liver by clinical, biochemical and ultrasonographic criteria was performed. Patients were treated with 1500 mg/day of metadoxine (n = 69) or placebo (n = 67) for 3 months. Patients were clinically and biochemically evaluated every month. Ultrasonography was performed before and after treatment. RESULTS: At the end of the study there was a significant improvement in the liver function tests in both groups. However, the changes were more rapid and greater in patients treated with metadoxine, in whom significant changes in serum levels of bilirubin, aminotransferases and gammaglutamyl transpeptidase were already observed after 1 month of treatment, and normalization of these parameters was observed at the end. After treatment, the percentage of patients with ultrasonographic signs of steatosis was significantly lower in the metadoxine group (28% vs 70%, p < 0.01) and the degree of steatosis was also lower in this group. Sixteen patients treated with metadoxine and 15 with placebo continued drinking. Alcohol intake was lower than initially, and similar in both groups. In the metadoxine group, the biochemical changes were similar in both the abstinent and the nonabstinent patients. In contrast, in the placebo group the improvement in the liver function tests was significantly higher in abstinents. Among patients who continued drinking, the prevalence (45% vs 92%, p < 0.05) and the degree of steatosis were also significantly lower in patients treated with metadoxine. CONCLUSIONS: In patients with alcoholic fatty liver, metadoxine accelerates the normalization of liver function tests and the ultrasonographic changes, even in those who do not completely abstain from alcohol intake. Thus, metadoxine could be useful in the treatment of the early stages of alcoholic liver disease.

Adult↗
PubMed2000

The anti-dementia drug nefiracetam facilitates hippocampal synaptic transmission by functionally targeting presynaptic nicotinic ACh receptors.

Nefiracetam, a pyrrolidone derivative developed as an anti-dementia drug, persistently potentiated currents through neuronal nicotinic acetylcholine (ACh) receptors (alpha7, alpha4beta2) expressed in Xenopus oocytes, and the potentiation was blocked by either the selective protein kinase C (PKC) inhibitors, GF109203X and staurosporine, or co-expressed active PKC inhibitor peptide. In primary cultures of rat hippocampal neurons, nefiracetam increased the rate of nicotine-sensitive miniature excitatory postsynaptic currents, without affecting the amplitude, and the increase was inhibited by GF109203X. In addition, the drug caused a marked increase in the glutamate release from electrically stimulated guinea pig hippocampal slices, and the effect was abolished by the nicotinic ACh receptor antagonists, alpha-bungarotoxin and mecamylamine. Nefiracetam induced a long-lasting facilitation of synaptic transmission in both the CA1 area and the dentate gyrus of rat hippocampal slices, and the facilitation was inhibited by alpha-bungarotoxin and mecamylamine. Such facilitatory action was still found in the hippocampus with selective cholinergic denervation. The results of the present study, thus, suggest that nefiracetam enhances activity of nicotinic ACh receptors by interacting with a PKC pathway, thereby increasing glutamate release from presynaptic terminals, and then leading to a sustained facilitation of hippocampal neurotransmission. This may represent a cellular mechanism underlying the cognition-enhancing action of nefiracetam. The results also provide the possibility that nefiracetam could be developed as a promising therapeutic drug for senile dementia or Alzheimer's disease.

Animals↗
PubMed1983

On the bioavailability of topical formulations of clindamycin hydrochloride.

The role of the vehicle in the percutaneous absorption of clindamycin hydrochloride has been studied. Fourteen vehicles have been examined for their ability (1) to adequately solubilize clindamycin and (2) to effect penetration of the drug into the skin. The solubility of clindamycin was found to be good in ten of the fourteen vehicles studied, with a drug concentration of greater than 1.0% being achieved. A vehicular water content of greater than 20% or the presence of another suitable cosolvent appeared to be necessary for adequate solubilization of drug. Percutaneous absorption varied greatly among the vehicles, ranging from 0.7% to 12.9% of the applied dose in 24 hours. The vehicles effecting the greatest clindamycin absorption contained the penetration enhancers dimethylsulfoxide or N-methyl-2-pyrrolidone. Overall, the vehicles studied varied a hundredfold with respect to clindamycin bioavailability. Correlation of these data with other literature data suggests a possible relationship between clindamycin bioavailability and clinical efficacy in the treatment of acne and, therefore, argues against extemporaneous compounding of this drug in the absence of bioavailability data.

Administration, Topical↗
PubMed2003

A standardized test to assess the impact of different organic challenges on the antimicrobial activity of antiseptics.

This paper presents a suggestion for determining the antimicrobial efficacy of antiseptics in a phase 2/step 1 assay. Emphasis is placed on specific organic challenges to evaluate the efficacy of antiseptics used to rinse the oral cavity, mucous membranes, or wounds for either prophylactic or therapeutic reasons. Basic data are given concerning ready-to-use products based on Poly(1-vinyl-2-pyrrolidone-)iodine-complex (PVP-iodine), chlorhexidine, octenidine, or cetylpyridinium chloride. Hydrogen peroxide (3.0%) was included to assess a product with known limited efficacy only. Using Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecium, and Candida albicans, a 10(5)-fold reduction can be achieved in 10 min without interfering substances. In the presence of 10% albumin, 10% sheep blood, or 1% mucin, a 10(3)-fold reduction is yielded using products based on PVP-iodine, octenidine, or chlorhexidine. The combination of 4.5% albumin, 4.5% sheep blood, and 1% mucin was the most difficult organic challenge and only the products based on PVP-iodine, octenidine, or chlorhexidine remained active. The cetylpyridinium-based product and hydrogen peroxide were less effective. Based on these data, a proposal for a phase 2/step 1 assay for antiseptics is presented to promote the standardization efforts.

Albumins↗
PubMed2001

Intracellular Mg2+ diffusion within isolated rat skeletal muscle fibers.

Intracellular free magnesium concentration ([Mg2+]i) was measured in enzymatically isolated rat skeletal muscle fibers using the fluorescent dye mag-indo-1. The change in [Mg2+]i produced by a local intracellular microinjection of magnesium pidolate (magnesium pyrrolidone carboxylate) was measured at a given distance from the injection site. In one series of experiments this protocol was tested on isolated fibers that were completely embedded into silicone grease: under these conditions, the injection produced an increase in [Mg2+]i that reached a steady level some time following the injection. The time-course of the [Mg2+]i change could be well accounted for by a model of longitudinal diffusion. The mean apparent Mg2+ diffusion coefficient (D(app)) was 188+/-9 microm2 s(-1) (n = 16), approximately four times lower than the value measured in vitro. This reduction likely results from the effects of cytoplasmic viscosity and of Mg2+ binding to low affinity static sites. Another series of measurements was performed on fibers that were either partially or completely free of silicone: under these conditions, the time course of the change in [Mg2+]i was in many cases more complex than predicted by simple diffusion.

Animals↗
PubMed2002

Advanced glycosylation end products induce NF-kappaB dependent iNOS expression in RAW 264.7 cells.

Advanced glycosylation end products (AGEs) have been implicated in the pathogenesis of diabetic complications. Treatment of RAW 264.7 macrophages with bovine serum albumin (BSA)-derived AGEs caused dose- and time-dependent increases in nitrite production and inducible nitric oxide synthase (iNOS) expression. These effects were blocked by the nuclear factor-kappa B (NF-kappaB) inhibitor, pyrrolidone dithiocarbamate (PDTC). BSA-AGEs also stimulated the translocation of p65 NF-kappaB from cytosol to the nucleus. Electrophoretic mobility shift assay revealed that the NF-kappaB DNA-protein-binding activity was enhanced by AGEs. The tyrosine kinase inhibitor, genistein, the phosphatidylinositol-3-kinase (PI 3-K) inhibitor, LY 294002, the protein kinase C (PKC) inhibitor, Ro 31-8220, and the p38 mitogen-activated protein kinase (MAPK) inhibitor, SB 203580, all inhibited AGEs-stimulated iNOS expression, NO release, NF-kappaB translocation and NF-kappaB DNA binding activity. These results suggest that AGEs may activate NF-kappaB via an upstream signaling cascade composed of tyrosine kinase, PI 3-K, PKC, and p38 MAPK, resulting in the induction of iNOS expression in RAW 264.7 macrophages.

Active Transport, Cell Nucleus↗
PubMed1997

Role of histidyl residues in the binding of ligands to the porcine N-methyl-D-aspartate receptor.

Possible involvement of histidyl residues in the binding of ligands to ionotropic glutamate receptors and to modulatory sites on the N-methyl-D-aspartate (NMDA) receptor was assessed in porcine cortical synaptic plasma membranes after covalent modification with diethyl pyrocarbonate (DEPC). Binding of [3H]glutamate to the NMDA sites was enhanced but to the 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate receptors unaffected by 1 and 5 mM DEPC. Binding of 3-[(R)-carboxypiperazin-4-yl]-[1,2-(3)H]propyl-1-phosphonate ([3H]CPP) was reduced in a dose-dependent manner by DEPC and the activation of binding by 1-hydroxy-3-amino-2-pyrrolidone (HA-966) blocked by 10 mM DEPC. DEPC reduced the strychnine-insensitive binding of [3H]glycine and the glycine- and glutamate-activated binding of [3H]dizocilpine. Protection experiments indicated that histidyl residues are directly involved in the binding of glycine (but not HA-966) and allosterically modulate the binding of glutamate, CPP and dizocilpine. The results corroborate the existence of agonist- and antagonist-preferring sites or conformational states of the NMDA receptors.

2-Amino-5-phosphonovalerate↗
PubMed1997

Selective depression of the spinal polysynaptic reflex by the NMDA receptor antagonists in an isolated spinal cord in vitro.

1. The effects of N-methyl-D-aspartate (NMDA) receptor glycine-binding site antagonists 7-chlorokynurenate (7-Clkyn) and (+/-)-3-amino-1-hydroxy-2-pyrrolidone (HA-966) on spinal reflexes in an isolated spinal cord that was maintained in Mg(2+)-free medium in vitro were examined. The actions of 7-Clkyn and HA-966 were compared with those of the channel-site antagonist (i.e., dizocilpine) and NMDA-binding site antagonists--that is, 3-[(+/-)-2-carboxypiperazin-4-yl]-propyl-1-phosphonate (CPP) and DL-2-amino-5-phosphonovalerate (APV). 2. 7-Clkyn and HA-966 produced a selective depression of the polysynaptic reflex (PSR) while negligibly affecting the activity of the monosynaptic reflex (MSR). The PSR was also differentially suppressed by dizocilpine, CPP and APV. The PSR inhibitory activity of the NMDA antagonists was in the following order: dizocilpine > CPP > APV = 7-Clkyn > HA-966. 3. The inhibitory effects of 7-Clkyn on PSR were markedly antagonized by the simultaneous application of D-serine, an agonist for the NMDA receptor glycine-binding sites. However, PSR inhibition by dizocilpine and CPP was unaffected. 4. Inhibition of the PSR by 7-Clkyn persisted in the presence of strychnine, which markedly increased the PSR activity by itself. 5. These findings suggest that the NMDA receptor glycine-binding sites play a role in generating the NMDA receptor-mediated PSR in the spinal cord in vitro.

Animals↗
PubMed1997

Pyroglutamic acid and iron regulate the expression of the pcp gene in Pseudomonas fluorescens MFO.

Pyrrolidone carboxyl peptidase (Pcp) is an aminopeptidase (EC 3.4.11.8) able to specifically remove the L-pyroglutamyl residue from the amino-terminus of polypeptides. Since nothing was known concerning the regulation and function of Pcps, a mutant of a milk-isolated strain lacking Pcp activity (Pseudomonas fluorescens MB1), was constructed by homologous recombination using a transcriptional fusion between pcp and a reporter gene (uidA). The wild-type and mutant strains were grown in synthetic media and in milk to investigate the environmental effects on pcp transcription. The expression of pcp and of the transcriptional fusion pcp::uidA was not sensitive to environmental conditions like temperature, osmolarity or nitrogen and phosphate starvation but was induced by the product of the enzymatic activity, pyroglutamic acid (pGlu). The expression of the native gene and the fusion in inducing conditions was also controlled by the iron concentration. The identification in the pcp promoter sequence of putative ferric uptake regulator (Fur) binding sites suggests a transcriptional regulation in a Fur-dependent fashion. Two other putative regulatory stretches, corresponding to inverted repeated sequences with perfect and imperfect symmetry, were also identified. pGlu and iron are therefore at least two of the transcriptional effectors of pcp expression.

Amino Acid Sequence↗
PubMed2000

Polymer displacement/shielding in protein chromatography.

An overview of different applications of polymer interactions with ion-exchange and dye-affinity chromatographic matrices is presented here. The strength of interaction between the ligand and the polymer plays a crucial role in deciding the mode of chromatographic application. Charged, non-ionic and thermosensitive polymers such as poly(ethylene imine), poly(N-vinyl pyrrolidone) and poly(vinyl caprolactam) respectively, show different degrees of interaction with the dye molecules in dye ligand chromatography. Polymers, with their ability of multipoint and hence strong attachment to the chromatographic matrices, were used as efficient displacers in displacement chromatography. The polymer displacement resulted in better recoveries and sharper elution profiles than traditional salt elutions. The globule-coil transition of the thermosensitive reversible soluble-insoluble polymer, poly(vinyl caprolactam), can be exploited in dye-affinity columns for the temperature induced displacement of the bound protein. In another situation, prior to the column chromatography of crude protein extract, polymers formed complexes with the dye matrix and "shielded" the column. The polymer shielding decreased the nonspecific interactions without affecting the specific interactions of the target protein to the dye matrix.

Chromatography↗
PubMed1982

Analysis of methadone and metabolites in biological fluids with gas chromatography--mass spectrometry.

The analysis of methadone and its metabolites in biological fluids by gas chromatography--mass spectrometry is described with deuterated methadone and metabolites as internal standards. The method allowed the determination of 20 ng methadone in 0.5 ml of plasma or saliva. Mean saliva to plasma ratio of methadone for two patients was determined to be 0.51 +/- 0.13. Methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in urine were measured by selected ion monitoring. Gas chromatography--mass spectrometry was found to have advantages over conventional gas chromatographic methods in terms of ratio analysis. 1,5-Dimethyl-3,3-diphenyl-2-pyrrolidone previously reported as a metabolite was shown to result primarily from the decomposition of EDDP free base.

Chromatography, Gas↗
PubMed1997

Determination of N-methylsuccinimide and 2-hydroxy-N-methylsuccinimide in human urine and plasma.

A method for determination of N-methylsuccinimide (MSI) and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine and of MSI in human plasma was developed. MSI and 2-HMSI are metabolites of the widely used organic solvent N-methyl-2-pyrrolidone (NMP). MSI and 2-HMSI were purified from urine and plasma by C8 solid-phase extraction and analysed by gas chromatography-mass spectrometry in the negative-ion chemical ionisation mode. The intra-day precisions in urine were 2-6% for MSI (50 and 400 ng/ml) and 3-5% for 2-HMSI (1000 and 8000 ng/ml). For MSI in plasma it was 2% (60 and 1200 ng/ml). The between-day precisions in urine were 3-4% for MSI (100 and 1000 ng/ml) and 2-4% for 2-HMSI (10,000 and 18,000 ng/ml) and 3-4% for MSI in plasma (100 and 900 ng/ml). The recoveries from urine were 109-117% for MSI (50 and 400 ng/ml) and 81-89% for 2-HMSI (1000 and 8000 ng/ml). The recovery of MSI from plasma was 91-101% (50 and 500 ng/ml). The detection limits for MSI were 3 ng/ml in urine and 1 ng/ml in plasma and that of 2-HMSI in urine was 200 ng/ml. The method is applicable for analysis of urine and plasma samples from workers exposed to NMP.

Drug Stability↗
PubMed2000

The impact of co-solvents and the composition of experimental formulations on the pump rate of the ALZET osmotic pump.

The water-miscible co-solvents polyethylene glycol 400 (PEG400), N-methyl-2-pyrrolidone (NMP), and N, N-dimethylacetamide (DMA) exhibit the potential to increase the solubility of poorly water-soluble compounds and therefore they represent promising vehicles for compound delivery using osmotic pumps in early discovery experiments. Thus, the selected co-solvents were investigated for their compatibility with the interior of ALZET osmotic pumps. Moreover, 1-week pumps were filled with mixtures of either the co-solvents with water (60:40, v/v), with neat PEG400, or with PEG400/water mixtures of different concentrations. It was determined whether the composition of an experimental formulation could have an impact on the overall pump rate with 14C-mannitol being used as the model compound. It was found that neat PEG400 was compatible with the reservoir material, whereas NMP and DMA were tolerable only in aqueous solutions up to 60%. PEG400, NMP, and DMA mixtures with water (60:40) resulted in release rates comparable to those of water and PEG400/water mixtures of lower co-solvent concentration. Moreover, as demonstrated using the various PEG400/water mixtures, the amount of co-solvent in the formulation had no significant impact on the overall release profile. By contrast, the use of neat PEG400 resulted in a significant decrease in the pump rate.

Drug Delivery Systems↗
PubMed2000

Ketorolac entrapped in polymeric micelles: preparation, characterisation and ocular anti-inflammatory studies.

Polymeric micelles made of copolymer of N-isopropylacrylamide (NIPAAM), vinyl pyrrolidone (VP) and acrylic acid (AA) having cross-linkage with N,N'-methylene bis-acrylamide (MBA) were used as host carrier in which up to 30%w/w ketorolac (free acid) was entrapped to make the formulation. The lyophilised powder was used for physical characterisation. The drug entrapment was found to be about 80% and the formulation was stable for 8-10 days at room temperature. The smaller the amount of ketorolac dissolved into the micelles, the longer was the formulation shelf life. The size of the particles as measured by dynamic light scattering was found to be around 35 nm diameter at 25 degrees C. TEM picture showed spherical particles. The structure of the polymer and its morphology were characterised by FTIR, NMR and XRD measurements. IR data indicated weak interaction between polymer and ketorolac in the encapsulated system. NMR spectra indicated rigid polymer backbone with intermittent iso-propyl group in the chain. XRD spectra showed significant loss of crystallinity of the drug while being entrapped in the polymeric micelles. The release of drug in aqueous buffer (pH 7.2) from the polymeric micelles at 25 degrees C were 20 and 60% after 2 and 8 h respectively and is temperature and pH dependent. In vitro corneal permeation studies through excised rabbit cornea indicated two fold increase in ocular availability with no corneal damage compared to an aqueous suspension containing same amount of drug as in nanoparticles. The formulation showed significant inhibition of lid closure up to 3 h and PMN migration up to 5 h compared to the suspension containing non-entrapped drug, which did not show any significant effect.

Acrylamides↗
PubMed2001

Crystallization of hydrocortisone acetate: influence of polymers.

The influence of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG400) on the crystallization of hydrocortisone acetate (HA) was studied. Supersaturation was created by the cosolvent technique. Spontaneous nucleation was observed when no polymer was used as the additive. In the presence of the polymer, nucleation was delayed. The nucleation time decreased with increasing supersaturation at a particular polymer concentration and increased with increasing polymer concentration at a particular supersaturation. Habit modification from a well-defined polar prismatic morphology to a wing-shaped morphology was observed when HPMC was used as the additive. The effect of PVP and PEG400 on the morphology of HA was less pronounced compared to the cellulose polymers. The mechanism of nucleation retardation by the polymers is explained in terms of association of HA with the polymer through hydrogen bonding. The growth may be inhibited by the hydrodynamic boundary layer, in which the polymers accumulate as well as by the adsorption of the polymer onto the crystal surface. The habit modification of HA by HPMC is due to different extents of adsorption on different faces of the crystal, the extent of which is dependent on the hydrogen bonding functional groups that are exposed at each face of the crystal.

Crystallization↗
PubMed2001

A comparison of alternative polymer excipients and processing methods for making solid dispersions of a poorly water soluble drug.

Solid dispersions were prepared with the extremely poorly water soluble drug, probucol and the water soluble polymers, polyvinyl pyrrolidone (PVP), polyacrylic acid (PAA) or polyethylene oxide (PEO) and blends of these polymers. The solid dispersions were prepared either by the solvent evaporation method, or by compression moulding into films. The materials were characterised by a combination of thermal analysis and FT-Raman spectroscopy. The physical state of the drug was observed to be dependent on the carrier, thus the PVP solid dispersions contained amorphous probucol, whilst the PAA and PEO systems contained the crystalline polymorph II. The method of production was not found to greatly influence the state of the drug in the solid dispersion. The greatest extent of release into solution was observed for the binary blend of drug and PEO, and the blending of polymers was not found to have any advantageous effects in this study.

Anticholesteremic Agents↗