Plasdone S-630 Research Articles

Investigation of the Influence of Copovidone Properties and Hot-Melt Extrusion Process on Level of Impurities, In Vitro Release, and Stability of an Amorphous Solid Dispersion Product.

Hot-melt extrusion (HME) is a widely used method for creating amorphous solid dispersions (ASDs) of poorly soluble drug substances, where the drug is molecularly dispersed in a solid polymer matrix. This study examines the impact of three different copovidone excipients, their reactive impurity levels, HME barrel temperature, and the distribution of colloidal silicon dioxide (SiO2) on impurity levels, stability, and drug release of ASDs and their tablets. Initial peroxide levels were higher in Kollidon VA 64 (KVA64) and Plasdone S630 (PS630) compared to Plasdone S630 Ultra (PS630U), leading to greater oxidative degradation of the drug in fresh ASD tablets. However, stability testing (50 °C, closed container, 50 °C/30% RH, open conditions) showed lower oxidative degradation impurities in ASD tablets prepared at higher barrel temperatures, likely due to greater peroxide degradation. Plasdone S630 is suitable for ASDs with drugs prone to oxidative degradation, while standard purity grades may benefit drugs susceptible to free radical degradation, as they generate fewer free radicals post-HME. ASD tablets exhibited greater physical stability than milled extrudate samples, likely due to reduced exposure to stability conditions within the tablet matrix. Including SiO2 in the extrudate composition resulted in greater physical stability of the ASD system in the tablet; however, it negatively affected chemical stability, promoting greater oxidative degradation and hydroxylation of the drug substance. No impact of the distribution of SiO2 on drug release was observed. The study also confirmed the congruent release of copovidone, the drug substance, and Tween 80 using flow NMR coupled with in-line UV/vis. This research highlights the critical roles of peroxide levels and SiO2 in influencing the dissolution and physical and chemical stability of ASDs. The findings provide valuable insights for developing stable and effective pharmaceutical formulations, emphasizing the importance of controlling reactive impurities and excipient characteristics in ASD products prepared by using HME.

Measuring and Modeling of Melt Viscosity for Drug Polymer Mixtures.

Melt viscosity is an essential property in pharmaceutical processes such as mixing, extrusion, fused deposition modeling, and melt coating. Measuring and modeling of the melt viscosity for drug/polymer mixtures is essential for optimization of the manufacturing process. In this work, the melt viscosity of nine formulations containing the drug substances acetaminophen, itraconazole, and griseofulvin, as well as the pharmaceutical polymers Eudragit EPO, Soluplus, and Plasdone S-630, were analyzed with a rotational and oscillatory rheometer. The shear rate, temperature, and drug fraction were varied systematically to investigate their influence on viscosity. The results for the pure polymers showed typical shear-thinning behavior and are fundamental for modeling with the Carreau and Arrhenius approaches. The investigations of the viscosity of the drug/polymer mixtures resulted in a plasticizing or a filler effect, depending on the type of drug and the phase behavior. A drug shift factor was proposed to model the change in viscosity as a function of the drug fraction. On this basis, a universal model to describe the melt viscosity of drug/polymer mixtures was developed, considering shear rate, temperature, and drug fraction.

DESIGN, OPTIMIZATION, AND CHARACTERIZATION OF A NOVEL AMORPHOUS SOLID DISPERSION FORMULATION FOR ENHANCEMENT OF SOLUBILITY AND DISSOLUTION OF TICAGRELOR

Objective: The study aims to enhance the solubility and dissolution of ticagrelor by formulating an amorphous solid dispersion using the hot melt extrusion technique. Methods: Solubility of ticagrelor is very limited in water and buffers of pH 1.2 to 6.8, which is one of the prime reasons for its low oral bioavailability. Amorphous solid dispersions were prepared using the Hot Melt Extrusion technique using different polymers, plasticizers, and surfactants. The formulation is optimized based on the level of polymer in the formulation. The final formulation of Ticagrelor Amorphous Solid Dispersion is made with a drug-polymer ratio of 1:3, keeping the plasticizer level at 10% of the polymer along with a surfactant Sodium Lauryl Sulfate. Results: The formulation showed an increase in solubility of 193.95-times in water, 50.71-times in 0.1 N HCl, 332.74-times in pH 4.5 acetate buffer, and 85.20-times in pH 6.8 phosphate buffer as compared to the pure drug. The drug release of the final formulation was found to be 70.0±4.4%, 55.4±1.1%, 35.5±2.1%, and 30.0±0.8% at 90 min, while the reference product showed a release of 9.4±1.1%, 20.7±0.5%, 8.4±0.3%, and 7.8±0.2% at 90 min in water, 0.1 N HCl, pH 4.5 acetate buffer and pH 6.8 Phosphate Buffer respectively. The drug release of the final formulation was found to be 99.1±3.8% at 60 min in 0.2% w/v Polysorbate-80 in water. Conclusion: In the present study, the amorphous solid dispersion of the poorly-soluble drug ticagrelor was successfully prepared. The polymer, Plasdone S630, is considered the most suitable with ticagrelor for formulating amorphous solid dispersion using Hot Melt Extrusion technology to increase the solubility and dissolution of the drug.

Predicting Residence Time and Melt Temperature in Pharmaceutical Hot Melt Extrusion.

Hot-melt extrusion is increasingly applied in the pharmaceutical area as a continuous processing technology, used to design custom products by co-processing drugs together with functional excipients. In this context, the residence time and processing temperature during extrusion are critical process parameters for ensuring the highest product qualities, particularly of thermosensitive materials. Within this study, a novel strategy is proposed to predict the residence time distribution and melt temperature during pharmaceutical hot-melt extrusion processes based on experimental data. To do this, an autogenic extrusion mode without external heating and cooling was applied to process three polymers (Plasdone S-630, Soluplus and Eudragit EPO) at different specific feed loads, which were set by the screw speed and the throughput. The residence time distributions were modeled based on a two-compartment approach that couples the behavior of a pipe and a stirred tank. The throughput showed a substantial effect on the residence time, whereas the influence of the screw speed was minor. On the other hand, the melt temperatures during extrusion were mainly affected by the screw speed compared to the influence of the throughput. Finally, the compilation of model parameters for the residence time and the melt temperature within design spaces serve as the basis for an optimized prediction of pharmaceutical hot-melt extrusion processes.

Predicting Throughput and Melt Temperature in Pharmaceutical Hot Melt Extrusion.

Even though hot melt extrusion (HME) is a commonly applied process in the pharmaceutical area, determination of the optimal process parameters is demanding. The goal of this study was to find a rational approach for predetermining suitable extrusion parameters, with a focus on material temperature and throughput. A two-step optimization procedure, called scale-independent optimization strategy (SIOS), was applied and developed further, including the use of an autogenic extrusion mode. Three different polymers (Plasdone S-630, Soluplus, and Eudragit EPO) were considered, and different optimal process parameters were assessed. The maximum barrel load was dependent on the polymers’ bulk density and the extruder size. The melt temperature was influenced by the screw speed and the rheological behavior of the polymer. The melt viscosity depended mainly on the screw speed and was self-adjusted in the autogenic extrusion. A new approach, called SIOS 2.0, was suggested for calculating the extrusion process parameters (screw speed, melt temperature and throughput) based on the material data and a few extrusion experiments.

Assessing compatibility of excipients selected for a sustained release formulation of bilberry leaf extract

The study is aimed to assess the compatibility of bilberry leaf powder extract (BLPE) with six excipients selected for sustained-release (SR) tablet formulation. The BLPE was obtained with the addition of L-arginine and Myo-inositol as the carriers. Thermogravimetric (TG-DTG) analysis and Fourier-transform infrared spectroscopy (FTIR), supported by Pearson correlation analysis, were applied to detect possible interactions in the binary mixtures (1:1) of the BLPE with each excipient. The TG-DTG showed some deviations in the thermal behavior of the BLPE / excipient mixtures. However, only the thermal behavior of magnesium stearate in the mixture significantly differed from individual samples, which suggested chemical interaction for this excipient. The FTIR analysis confirmed that the BLPE is compatible with Eudragit L100, Methocel K4M, Methocel K100LV, Avicel PH-101, and Plasdone S-630. Whereas it undergoes solid-state chemical interaction in the binary mixture with magnesium stearate. According to the FTIR-spectra, it is suggested that this interaction results in the formation of stearic acid and alkalization of the medium. These findings evidence for the possibility of using TG-DTG analysis as an independent thermal technique for compatibility studies and also confirm the earlier reported interaction of basic lubricants, e.g., stearic salts, with active ingredients containing amino groups.

РАЗРАБОТКА СОСТАВА И ТЕХНОЛОГИИ ТАБЛЕТОК, ПОКРЫТЫХ ОБОЛОЧКОЙ, С ЭКСТРАКТОМ RHEUM CORDATUM LOSINSK

Objective: Development of a rational composition, optimal technology, standardization criteria for tablets with Rheum cordatum extract, establishing the stability of the composition and storage conditions. Methods: As an active pharmaceutical substance, a standardized extract of Rheum cordatum was used. Pharmacopoeial excipients for the production of tablet mass are magnesium hydroxycarbonate, croscarmellose sodium, microcrystalline cellulose, Plasdone S-630, magnesium aluminum metasilicate, calcium stearate, purified water and film coating Opadry 85F18422 White. To obtain tablets qualified equipment was used in the technological process: a tablet mass mixer, a rotary tablet press, highly efficient film coating equipment, a packaging machine / blister machine. When developing the tablets, we were guided by the «Quality by design» concept of medicines, based on ICH guidelines: ICH Q11 «Development and manufacture of medicinal substances», ICH Q8 «Pharmaceutical Development» and ICH Q10 «Pharmaceutical Quality System». Standard pharmacopoeial research methods were used. Results: 50 experimental mass models for tableting have been developed in the variants of combining excipients and active substance in an effective single dose of 300 mg. Only 4 models of the core tablets obtained met the selection criteria (abrasion, crush resistance, disintegration, and dissolution). The optimal tableting method using wet granulation is substantiated, which makes it possible to obtain tablets of the proper pharmacopoeial quality and the following composition: soft rhubarb root extract, magnesium hydroxycarbonate, croscarmellose sodium, microcrystalline cellulose 102, Plasdone S-630, magnesium aluminum metasilicate, calcium stearate. To coat the obtained tablet cores, the following film coating composition was selected: Opadry 85F18422 White, consisting of polyvinyl alcohol, titanium dioxide E 171, macrogol 4000 and talc. Conclusions: The pharmaceutical development of coated tablets with an extract of Rheum cordatum has been done. The rational composition and optimal technology for producing tablet cores coated with a film coating of Opadry 85F18422 White were established. The quality of the obtained tablets was evaluated, the stability of the composition for 9 months was studied, the results of quality indicators are within acceptable standards, and research in this direction is going on. Keywords: Extract, coated tablets, pharmaceutical development, composition, technology, stability.

The Effect of Cooling on the Degree of Crystallinity, Solid-State Properties, and Dissolution Rate of Multi-Component Hot-Melt Extruded Solid Dispersions.

The effect of cooling on the degree of crystallinity, solid-state and dissolution properties of multi-component hot-melt extruded solid dispersions [SD] is of great interest for the successful formulation of amorphous SDs and is an area that is unreported, especially in the context of improving the stability of these specific systems. The thermal solid-state properties, degree of crystallinity, drug–polymer interactions, solubility and physical stability over time were investigated. X-ray powder diffraction [XRPD] and hyper differential scanning calorimetry [DSC] confirmed that indomethacin [INM] was converted to the amorphous state; however, the addition of poloxamer 407 [P407] had a significant effect on the degree of crystallinity and the solubility of the SD formulations. Spectroscopy studies identified the mechanism of interaction and solubility studies, showing a higher dissolution rate compared to amorphous and pure INM in pH 1.2 with a kinetic solubility of 20.63 µg/mL and 34.7 µg/mL after 3 and 24 h. XRPD confirmed that INM remained amorphous after 5 months stability testing in solid solutions with Poly(vinylpyrrolidone-co-vinyl acetate) [PVP VA64] and Plasdone S-630 [PL-S630]. Although cooling had a significant effect on the degree of crystallinity and on solubility of INM, the cooling method used did not have any significant effect on the amorphous stability of INM over time.

Use of Terahertz-Raman Spectroscopy to Determine Solubility of the Crystalline Active Pharmaceutical Ingredient in Polymeric Matrices during Hot Melt Extrusion

Polymer-based amorphous solid dispersions (ASDs) comprise one of the most promising formulation strategies devised to improve the oral bioavailability of poorly water-soluble drugs. Exploitation of such systems in marketed products has been limited because of poor understanding of physical stability. The internal disordered structure and increased free energy provide a thermodynamic driving force for phase separation and recrystallization, which can compromise therapeutic efficacy and limit product shelf life. A primary concern in the development of stable ASDs is the solubility of the drug in the polymeric carrier, but there is a scarcity of reliable analytical techniques for its determination. In this work, terahertz (THz) Raman spectroscopy was introduced as a novel empirical approach to determine the saturated solubility of crystalline active pharmaceutical ingredient (API) in polymeric matrices directly during hot melt extrusion. The solubility of a model compound, paracetamol, in two polymer systems, Affinisol 15LV (HPMC) and Plasdone S630 (copovidone), was determined by monitoring the API structural phase transitions from crystalline to amorphous as an excess of crystalline drug dissolved in the polymeric matrix. THz-Raman results enabled construction of solubility phase diagrams and highlighted significant differences in the solubilization capacity of the two polymer systems. The maximum stable API-load was 20 wt % for Affinisol 15LV and 40 wt % for Plasdone S630. Differential scanning calorimetry and XRPD studies corroborated these results. This approach has demonstrated a novel capability to provide real-time API–polymer phase equilibria data in a manufacturing relevant environment and promising potential to predict solid-state solubility and physical stability of ASDs.

An investigation of the inter-molecular interaction, solid-state properties and dissolution properties of mixed copovidone hot-melt extruded solid dispersions

Previous research has focused on spray dried quaternary mixtures which, due to the addition of a surfactant, affected the physical stability and amorphous stability of selected model drugs. Very little research has focused on how inter-molecular interactions play a role in the successful formulation of hot-melt extruded quaternary amorphous blends and how they affect physical stability and solubility of amorphous solid dispersions (ASDs). Therefore the aim of this study was to investigate the role of inter-molecular interactions and their effect on the solid-state and dissolution properties of mixed copovidone amorphous solid dispersions (ASDs). The polymeric copovidone carriers used in this study were Poly (vinylpyrrolidone-vinyl acetate copolymer) and Plasdone S-630 (PL-S630) which in terms of monographs are the same, however they have different solid-state and dissolution properties. The ASDs showed a significantly higher dissolution rate compared to amorphous and pure INM in pH buffer 1.2 with a kinetic solubility of 24 μg/ml. The stability data showed that INM remained amorphous in solid solutions with PVP VA64 and Plasdone S-630, except for the higher drug loads. It was concluded that % drug loading did have a significant effect on the solubility of INM due to recrystallization at higher drug loads.

Formulation of Gastro-retentive Floating Tablets of Valsartan by 2 power 2 Factorial Designs: In vitro and In vivo Evaluations

An oral dosage form containing gastro-retentive floating tablets forms a stomach-specific drug delivery system for the treatment of hypertension. Valsartan belongs to the BCS class II (poo Classification System). It is desirable to improve the extent of bioavailability (23%). The objective of the present study was to apply design of experiment to optimize floating drug delivery of valsartan by employing 22 factorial design. Improvement of the aqueous solubility of valsartan was done by solid dispersions using hot melt extrusion technique. Plasdone S630 copovidone is a variable carrier and drug to carrier ratio of 1:2 was optimized. Valsartan floating tablets were prepared by employing factorial design (22), where HPMC K15M (X1) and pregelatinized starch (X2) were independent variables and drug dissolution was the dependent parameter (Y1) to prepare matrix tablets. The factorial analysis, steepest ascent method was utilized for obtaining optimized formulation. In vitro evaluation, In vivo radiographic study and biopharmaceutical analysis in rabbits for valsartan optimized formulation (FT-5). Floating lag time (FLT) for valsartan optimized formulation (FT-5) was 15 s and total floating time (TFT) of the tablets was about 33 h, which was satisfactory. A four-point (1 h, 4 h, 8 h and 16 h) dissolution analysis gave satisfactory dissolution profile up to 24 h. The release kinetics of valsartan optimized formulation (FT-5) followed zero order and the release mechanism was found to be Korsemeyer Peppas model, i.e. swelling type. The dissolution efficiency for valsartan floating tablets was 1190.89% against the marketed formulation of 39.77%. The accelerated stability profile of valsartan optimized formulation (FT-5) was evaluated in terms of drug content and percent cumulative dissolution of valsartan in 24 h, in a 6 months study. In vivo X-ray image study for valsartan optimized formulation (FT-5) indicated the presence of intact tablet up to 12 h in gastric region of rabbit. The biopharmaceutical analysis in rabbits was conducted for valsartan optimized formulation (FT-5). The HPLC method was established and validated for the in vivo analysis. The Cmax was 453.2 ng/mL compared to that of the marketed tablets (522.4 ng/mL). The mean residence time (MRT) for the valsartan optimized formulation (FT-5) was 14.82 h as against 4 h for marketed tablet. The relative bioavailability of valsartan optimized formulation (FT-5) was 650% higher than the marketed tablet. To overcome the poor bioavailability of valsartan, it was suitably modified using hot-melt extrusion for improving therapeutic outcome. In conclusion, gastro-retentive drug delivery system is an excellent approach for improving the bioavailability of valsartan. 

Dissolution Enhancement in Cocoa Extract, Combining Hydrophilic Polymers through Hot-Melt Extrusion

The aim of this study was to improve the physicochemical properties of cocoa extract (CE) using hot-melt extrusion (HME) for pharmaceutical proposes. A mixture design was applied using three distinct hydrophilic polymeric matrices (Soluplus, Plasdone S630, and Eudragit E). Systems obtained by HME were evaluated using morphologic, chromatographic, thermic, spectroscopic, and diffractometric assays. The flow, wettability, and dissolution rate of HME powders were also assessed. Both CE and its marker theobromine proved to be stable under heating according to thermal analysis and Arrhenius plot under isothermal conditions. Physicochemical analysis confirmed the stability of CE HME preparations and provided evidence of drug–polymer interactions. Improvements in the functional characteristics of CE were observed after the extrusion process, particularly in dissolution and flow properties. In addition, the use of a mixture design allowed the identification of synergic effects by excipient combination. The optimized combination of polymers obtained considering four different aspects showed that a mixture of the Soluplus, Plasdone S630, and Eudragit E in equal proportions produced the best results (flowability index 88%; contact angle 47°; dispersibility 7.5%; and dissolution efficiency 87%), therefore making the pharmaceutical use of CE more feasible.

Dissolution Enhancement of Raltegravir by Hot Melt Extrusion Technique

The objective of the study to develop an amorphous solid dispersion for poorly soluble raltegravir by hot melt extrusion (HME) technique. A novel solubility improving agent plasdone s630 was utilized. The HME raltegravir was formulated into tablet by direct compression method. The prepared tablets were assessed for all pre and post-compression parameters. The drug- excipients interaction was examined by FTIR and DSC. All formulas displayed complying with pharmacopoeial measures. The study reveals that formula prepared by utilizing drug and plasdone S630 at 1:1.5 proportion and span 20 at concentration about 30mg (trail-6) has given highest dissolution rate than contrasted with various formulas of raltegravir.
 Keywords: Hot melt extrusion, Raltegravir, Plasdone S630.

PREPARATION AND CHARACTERIZATION OF NANOCRYSTALS FOR SOLUBILITY AND DISSOLUTION RATE ENHANCEMENT OF PALIPERIDONE USING DIFFERENT HYDROPHILIC CARRIERS: IN VITRO-IN VIVO STUDY

Objective: The objective of this study was to increase the solubility and dissolution rate of paliperidone (PAL) by preparing its nanocrystals using different hydrophilic carriers by antisolvent precipitation technique.Methods: The nanoparticles (NP) were characterized for aqueous solubility, drug content, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, particle size, and in vitro-in vivo analysis.Results: The results showed improved solubility and dissolution rate of NPs when compared to pure drug and physical mixture (PM). Solubility data showed a linear graph giving an indication that there is a gradual increase in the solubility profile of the drug with an increase in concentration of the carriers. At highest concentration, the solubility of NPs with Plasdone S630, Povidone K-25, and PVP K-30 found to be increased by 12 folds, 9 folds and 6 folds, respectively, as compared to pure drug. The release profile of NPs with Plasdone S630 in terms of dissolution efficiency at 60 min (DE60), initial dissolution rate (IDR), amount release in 15 min (Q15 min), and time for 75% release (t75%) shows better results when compared to pure drug, PM, and also NPs with povidone 25 and povidone 30. In vivo study reveals that optimized NPs elicited significant induction of cataleptic behavior which is the indication of antipsychotic agent(s) effect.Conclusion: The process antisolvent precipitation under constant stirring may be a promising method to produce stable PAL NPs with markedly enhanced solubility and dissolution rate due to nanonization with the increased surface area, improved wettability, and reduced diffusion pathway.

Development of Nevirapine Tablets by Direct Compression Method Using Solid Dispersion Technique

Purpose : The aim of the research is to develop Nevirapine tablets by direct compression method by improving solubility using solid dispersion technique. Methodology : Nevirapine is anti-viral drug, which is used in the prevention and treatment of HIV infections. It belongs to class II drug in Bio-Pharmaceutical Classification System i.e. low solubility and high permeability. It has a biological half-life of 45 hours. One of the major problems with this drug is its low solubility in biological fluids, which results into poor bioavailability after oral administration. Here, solid dispersions of Nevirapine are prepared with different carriers such as Plasdone S-630 and Soluplus in order to increase its solubility and dissolution rate. By increasing the solubility of Nevirapine, its bioavailability can be increased. Pre-formulation studies regarding the drug-carrier interaction was carried out by fourier transform infrared spectroscopy and differential scanning calorimetry. Nevirapine solid dispersions were evaluated for solubility, drug content estimation and in vitro dissolution studies. Powder blend was evaluated for bulk density, tapped density, Carr's index, Hausner's ratio and angle of repose. Findings : The dissolution pattern of the Nevirapine from all the standard dispersions followed predominantly first order kinetics. The study reflects the vital role of polymers as a novel approach to improve the solubility of nevirapine, which could minimize the variable dissolution rate with increase in bioavailability. With the studies conducted, the percentage drug release of Nevirapine was increased by melting method with Nevirapine: Plasdone S630 in the ratio of 1:2. Practical implications : Nevirapine is a suitable drug to formulate into tablet by using the above mentioned carriers and may provide a better therapeutic profile than that of conventional dosage form.

Enhancing the oral bioavailability of biochanin A by encapsulation in mixed micelles containing Pluronic F127 and Plasdone S630.

Biochanin A (BCA), a natural dietary isoflavone, has been reported to show anticancer activities. However, its low biological availability and poor aqueous solubility limit its usefulness as a chemotherapeutic agent. We developed BCA-loaded micelles with Pluronic F127 and Plasdone S630 (BCA-FS). The optimized, spherical-shaped BCA-FS was obtained at a ratio of 1:1 (F127:S630). The particle size was 25.17±1.2 nm, and the zeta potential was −10.9±0.24 mV. BCA solubility in water increased to 5.0 mg/mL after encapsulation, and the drug-loading efficiency was 5.88%±0.76%. In vitro release experiments showed a delayed release of BCA from the mixed micelles. Furthermore, the BCA absorption permeability across a Caco-2 cell monolayer from the apical side to the basolateral side increased by 54% in BCA-FS. A pharmacokinetics evaluation showed a 2.16-fold increase in the relative oral bioavailability of BCA-FS compared with raw BCA, indicating that the mixed micelles may promote absorption in the gastrointestinal tract. A gastrointestinal safety assay was used to assess the reliability and safety of BCA-FS. On the basis of these findings, we conclude that this simple nanomicelle system could be leveraged to deliver BCA and other hydrophobic drugs.

Comparative study of mode of addition of super Disintegrants on Methocarbamol tablets by Roller Compaction method

Methocarbamol, a BCS class II drug is an antispasmodic agent used to treat the spasms from peripheral musculoskeletal conditions. The research focus in recent years has shifted to the formulation of both fast dissolving and disintegrating tablets that are swallowed and tablets that are intended to dissolving in the oral cavity. Super-disintegrants are now frequently used in tablet formulation to improve the rate and extent of tablet disintegration and thus improve the rate of drug dissolution. The majority of this research has been directed at the function-related properties of the super-disintegrants with special emphasis on correlating these properties to disintegrant efficiency and drug release. The present study was to formulate immediate release tablets using various types of disintegrants in order to investigate the effect of mode of incorporation of disintegrants on release of drug from tablets. Methocarbamol immediate release tablets were prepared by the roller compaction method by using a plasdone S630 as binder and four different disintegrants in combination of three modes of incorporation. The prepared tablets were characterized based upon their physicochemical characteristics. The results showed that F4 (CCS) and F7 (PP-XL) 3 % formulations exhibit faster release when compared to others. It may be concluded that intra-granular addition has given improved drug release from dosage form when compared to extra-granular and both intra and extra-granular addition.

Controlled delivery of carvedilol nanosuspension from osmotic pump capsule: In vitro and in vivo evaluation

This study intended to develop a novel controlled delivery osmotic pump capsule of carvedilol nanosuspension. The capsule is assembled using a semi-permeable capsule shell with contents including nanosuspension drying powder, mannitol and Plasdone S-630. The physical characteristics of semi-permeable capsule walls were compared among different coating solutions under different temperature. The composition of the coating solution and drying temperature appeared to be important for the formation of the shells. Carvedilol nanosuspension was prepared by precipitation–ultrasonication technique and was further lyophilized. Response surface methodology was used to investigate the influence of factors on the responses. The optimized formulation displayed complete drug delivery and zero-order release rate. The TEM and particle size analysis indicated that the morphology of the resultant nanoparticle in the capsule was spherical shaped with a mean size of 252±19nm. The in vivo test in beagle dogs demonstrated that the relative bioavailability of the novel system was 203.5% in comparison to that of the marketed preparation. The capsule successfully controlled the release of carvedilol and the fluctuation of plasma concentration was minimized. The system is a promising strategy to improve the oral bioavailability for poorly soluble drugs and preparing it into elementary osmotic pump conveniently.

Preparation of osthole-polymer solid dispersions by hot-melt extrusion for dissolution and bioavailability enhancement

The aim of this study was to investigate the potential of solid dispersion to improve the dissolution rate and bioavailability of osthole (Ost), a coumarin derivative with various pharmacological activities but with poor aqueous solubility. In present studies, the Ost solid dispersions were prepared with various polymers including Plasdone S-630, HPMC-E5, Eudragit EPO, and Soluplus by hot-melt extrusion method. In vitro characterizations were performed with differential scanning calorimetry (DSC), X-ray powder diffraction (XPRD), Fourier transform infrared (FT-IR) spectroscopy, and in vitro dissolution studies. In addition, in vivo pharmacokinetic studies of Ost solid dispersions were also conducted in rats after a single oral dose. In comparison to the untreated Ost coarse powder and the physical mixture with polymers, the solid dispersions prepared with Plasdone S-630 or HPMC-E5 (drug/polymer: 1:6) showed a significant enhancement of dissolution rate (∼3-fold higher D30). In addition, such preparations exhibited a significantly decreased Tmax, ∼5-fold higher Cmax and ∼1.4-fold higher AUC when comparing with Ost coarse powder. In conclusion, solid dispersion prepared with appropriate polymer could serve as a promising formulation approach to enhance the dissolution rate and hence oral bioavailability of Ost.

Dissolution rate and bioavailability enhancement of co-ground mixtures of paliperidone, with different hydrophilic carriers

Co-ground mixtures of poorly water soluble drug Paliperidone (PAL) with different hydrophilic carriers [Polyvinylpyrrolidine (Plasdone K-25 and Plasdone S-630), Hydroxypropyl methyl cellulose (HPMC), Hydroxypropylcellulose (HPC) and Sodium alginate were prepared to improve the dissolution rate of PAL. Co-grinding with PVP, especially with PVP- S630 (Vinyl pyrrolidone/ vinyl acetate co-polymer), was more effective in reduction of particle size than milling of drug alone. DSC studies indicated that crystalline nature of drug was reduced after co-grinding with PVP grades as compared to their corresponding physical mixtures. The hydrophilic carriers other than PVP did not reduce the crystalline nature of the drug significantly. X-ray diffraction (XRD) was carried out for selected batches to confirm DSC results. Significant enhancement in dissolution rate as well as extent was observed with co-ground mixtures of drug and PVP. Among all the prepared batches in this study, co-ground mixture of PAL and Plasdone S-630 in 1:1 ratio showed best results in terms of extent of dissolution as well as dissolution rate in water. This effect was not only due to particle size reduction, but also loss of crystalline nature of the drug during co-grinding. PVP was found to be a better carrier among the different hydrophilic carriers used in the study for improving the dissolution characteristics of PAL. The extent of the mean plasma exposures of PAL was 7-fold higher in animals treated with co-ground mixture of PAL, Plasdone S630 (1:1) compared to animals treated with Pure PAL.DOI: http://dx.doi.org/10.3329/icpj.v2i3.13632 International Current Pharmaceutical Journal, February 2013, 2(3): 70-77