Pharmacological and histological examination of atorvastatin-PVP K30 solid dispersions

Significant progress in improving Atorvastatin dissolution rate: Physicochemical characterization and stability assessment of self-dispersible Atorvastatin/Tween 80® nanocrystals formulated through wet milling and freeze-drying

Atorvastatin (ATV) is a first-line drug for the treatment of hyperlipidemia. This drug presents biopharmaceutical problems, partly due to its low solubility and dissolution rate. In this work, nanocrystals of ATV stabilized with Tween 80® were designed by wet milling. A full factorial design was applied to optimize the process. Additionally, a cryoprotectant agent (maltodextrin, MTX) was identified, which allowed maintaining the properties of the nanocrystals after lyophilization. The storage stability of the nanocrystals was demonstrated for six months in different conditions. The obtained nanocrystal powder was characterized using SEM, EDXS, TEM, DSC, TGA, FT-IR, and XRD, showing the presence of irregular crystals with semi-amorphous characteristics, likely due to the particle collision process. Based on the reduction in particle size and the decrease in drug crystallinity, a significant increase in water and phosphate buffer (pH 6.8) solubility by 4 and 6 times, respectively, was observed. On the other hand, a noticeable increase in the dissolution rate was observed, with 90 % of the drug dissolved within 60 min of study, compared to 30 % of the drug dissolved within 12 h in the case of the untreated drug or the physical mixture of components. Based on these results, it can be concluded that the nano-milling of Atorvastatin stabilized with Tween 80® is a promising strategy for developing new formulations with improved biopharmaceutical properties of this widely used drug.

Solid dispersions of atorvastatin with Kolliphor RH40: Enhanced supersaturation and improvement in a hyperlipidemic rat model

Atorvastatin is a potent lipid-lowering drug with poor solubility and high presystemic clearance that limits its therapeutic efficacy. The aim of this study was to develop solid dispersions and micellar systems to obtain fast-dissolving atorvastatin systems that enhances their anti-hyperlipidemic effect. Solubility and wettability studies allow the development of solid dispersions with low proportions of croscarmellose sodium as hydrophilic carrier. Solid state characterization studies indicated that the addition of Kolliphor® RH40 surfactant to solid dispersions increases intermolecular hydrogen bonding between drug and polymer chains. Dissolution studies in biorelevant Fasted State Simulate Intestinal Fluid (FaSSIF pH 6.5) medium showed for atorvastatin solid dispersion a supersaturation peak of atorvastatin followed by an aggregation/precipitation process. Only the presence of a surfactant such as Kolliphor® RH40 in atorvastatin micellar system, promotes the presence of micelles that achieve delayed recrystallization. Efficacy studies were carried out using a hyperlipidemic model of rats fed with a high- fat diet. The atorvastatin micellar system at doses of 10 mg/kg, revealed a significant improvement in serum levels of total cholesterol, low-density lipoproteins, and triglycerides compared to atorvastatin raw material. This micellar system also exhibited more beneficial effects on liver steatosis, inflammation and ballooning injury.

Development and assessment of phospholipid-based luteolin-loaded lipid nanocapsules for skin delivery

Luteolin is an excellent flavone possessing several beneficial properties such as antioxidant and anti-inflammatory effects which are interesting for skin delivery. Development of an appropriate skin delivery system could be a promising strategy to improve luteolin cutaneous performance.So, the main aim of this work was to fabricate, characterize and evaluate phospholipid-based luteolin-loaded lipid nanocapsules for skin delivery. The influence of phospholipid/oil ratio, surfactant type and chitosan coating were investigated. The prepared formulations underwent in vitro assessment and the selected formulations were evaluated ex vivo and in vivo. The mean diameters of investigated formulations varied between 174 nm and 628 nm while zeta potential varied between -25.7 ± 4.8 mV and 6.8 ± 1.7 mV. Increasing in phospholipid/oil ratios resulted in decrease in particles size with little effect on zeta potential and drug encapsulation. Cremophor EL showed the lowest particle sizes and the highest drug encapsulation. Chitosan coating shifted zeta potential towards positive values. Structural analyses showed that luteolin is incorporated into lipid core of nanocapsules. Selected formulations (LNC4 and LNC13) exhibited sustained in vitro release and antioxidant activity. LNC13 (chitosan coated) showed higher flux (0.457 ± 0.113 µg/cm²/h), permeability (45.70 ± 11.66 *10^-5 cm²/h) and skin retention (121.66 ± 7.6 µg/cm² after 24 h) when compared to LNC4 and suspension. It also showed disordered the integrity of the stratum corneum, increased epidermal thickness and relieving most of inflammatory features in animal model. In conclusion, this study proves that lipid nanocapsules could effectively deliver luteolin into skin and then can be established as a potential system in the pharmaceutical and cosmeceutical horizons.

Solubility enhancement of some poorly soluble drugs by solid dispersion using Ziziphus spina-christi gum polymer

A high percentage of marketed drugs suffer from poor water solubility and require an appropriate technique to increase their solubility. This study aims to compare physically modified and unmodified gum polymers extracted from Ziziphus spina-christi fruits as solid dispersion carriers for some drugs. Taguchi Orthogonal Design (L9) was chosen for the screening and optimization of the solid dispersions. The design has four factors: type of drug, type of polymer, type of solid dispersion process, and drug to polymer ratio. Each factor was varied in three stages and the total number of runs was 9 in triplicate. The polymer was physically modified by heating (M1ZG) or freeze-drying (M2ZG). The drugs were selected according to the biopharmaceutical classification system, namely loratadine and glimepiride (class II) and furosemide (class IV). Drugs were dispersed in the polymer in three different ratios 1: 1, 1: 2, and 1: 3. Solid dispersions were made by co-grinding, solvent evaporation, and kneading methods. Modified and unmodified polymers were characterized in terms of their organoleptic properties, solubility, powder flowability, density, viscosity, swelling index, and water retention capacity. Solid dispersions were characterized in terms of percentage practical yield, solubility improvement, and drug compatibility. The results showed that the organoleptic properties of polymers were not changed by the gum modification. The swelling index of the polymer was doubled in M1ZG. The viscosity and water retention capacity of the polymer was increased in both modified polymers. All solid dispersions showed a high practical percentage yield of more than 93%, the higher values ​​being more associated with loratadine and furosemide than with glimepiride. The improvement in solubility was observed in all solid dispersions prepared, the values ​​varying with the pH of the medium and the method of modification. The FTIR results indicated that there was no chemical interaction between these drugs and the polymer used. Analysis of the results according to the Taguchi orthogonal design indicated 51 folds aqueous solubility enhancement for loratadine using M2ZG polymer at a ratio of 1: 3 of Drug: polymer. This study showed the possibility of improving the solubility of other poorly soluble drugs.

Development of the Binary and Ternary Atorvastatin Solid Dispersions: In Vitro and In Vivo Investigations

The object of this study was to prepare binary and ternary solid dispersions of atorvastatin (ATR) by the melting method using PEGs and poloxamer 188 (P188) as the carriers, singly and in combination with each other. Dissolution behavior, solubility studies, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy were studied. Furthermore, antihyperlipidemic activities of formulations were compared to each other by serum lipid analyses in hyperlipidemic rats. Based on the results, the highest dissolution efficiency (DE30 = 83%) was obtained by binary systems consisted of ATR and P188. Also, no additional improvement was observed in dissolution properties of ternary solid dispersion formulations. Solubility studies showed enhancement of ATR phase solubility in water and a buffer solution containing P188 or PEG 10000. Furthermore, saturated solubility of ATR in the buffer solution improved more than twofold in the optimized ternary dispersion system. No crystalline changes occurred in PEG-based formulations; meanwhile, partial amorphization happened in the ATR-P188 combination. Finally, the in vivo study in hyperlipidemic rats exhibited a rapid decrease in the lipid profile of all formulations compared to ATR (after 7 days). Moreover, reduction of serum triglycerides and total cholesterol on the 14th day in the ATR group (p value < 0.01) was less than solid dispersion or physical mixing preparations (p value < 0.001). These findings proved the appropriate influence of using PEG and P188 in solid dispersion systems for the improvement of the therapeutic efficiency of ATR.

Formulation of Gelucire®-Based Solid Dispersions of Atorvastatin Calcium: In Vitro Dissolution and In Vivo Bioavailability Study

Atorvastatin (ATV) is a poorly water-soluble drug that exhibits poor oral bioavailability. Therefore, present research was designed to develop ATV solid dispersions (SDs) to enhance the solubility, drug release, and oral bioavailability. Various SDs of ATV were formulated by conventional and microwave-induced melting methods using Gelucire®48/16 as a carrier. The formulated SDs were characterized for different physicochemical characterizations, drug release, and oral bioavailability studies. The results obtained from the different physicochemical characterization indicate the molecular dispersion of ATV within various SDs. The drug polymer interaction results showed no interaction between ATV and used carrier. There was marked enhancement in the solubility (1.95-9.32 folds) was observed for ATV in prepared SDs as compare to pure ATV. The drug content was found to be in the range of 96.19% ± 2.14% to 98.34% ± 1.32%. The drug release results revealed significant enhancement in ATV release from prepared SDs compared to the pure drug and the marketed tablets. The formulation F8 showed high dissolution performance (% DE₃₀ value of 80.65 ± 3.05) among the other formulations. Optimized Gelucire®48/16-based SDs formulation suggested improved oral absorption of atorvastatin as evidenced with improved pharmacokinetic parameters (C_max 2864.33 ± 573.86 ng/ml; AUC_0-t 5594.95 ± 623.3 ng/h ml) as compared to ATV suspension (C_max 317.82 ± 63.56 ng/ml; AUC_0-t 573.94 ± 398.9 ng/h ml) and marketed tablets (C_max 852.72 ± 42.63 ng/ml; 4837.4 ± 174.7 ng/h ml). Conclusively, solid dispersion-based oral formulation of atorvastatin could be a promising approach for enhanced drug solubilization, dissolution, and subsequently improved absorption.

Polymers and Nanoparticles for Statin Delivery: Current Use and Future Perspectives in Cardiovascular Disease

Atherosclerosis-related coronary artery disease (CAD) is one of the leading sources of mortality and morbidity in the world. Primary and secondary prevention appear crucial to reduce CAD-related complications. In this scenario, statin treatment was shown to be clinically effective in the reduction of adverse events, but systemic administration provides suboptimal results. As an attempt to improve bioavailability and effectiveness, polymers and nanoparticles for statin delivery were recently investigated. Polymers and nanoparticles can help statin delivery and their effects by increasing oral bioavailability or enhancing target-specific interaction, leading to reduced vascular endothelial dysfunction, reduced intimal hyperplasia, reduced ischemia-reperfusion injury, increased cardiac regeneration, positive remodeling in the extracellular matrix, reduced neointimal growth and increased re-endothelization. Moreover, some innovative aspects described in other cardiovascular fields could be translated into the CAD scenario. Recent preclinical studies are underlining the effect of statins in the stimulation and differentiation of endogenous cardiac stem cells, as well as in targeting of local adverse conditions implicated in atherosclerosis, and statin delivery through poly-lactic-co-glycolic acid (PLGA) appears the most promising aspect of current research to enhance drug activity. The present review intends to summarize the current evidence about polymers and nanoparticles for statin delivery in the field of cardiovascular disease, trying to shed light on this topic and identify new avenues for future studies.

Enhancement of atorvastatin oral bioavailability via encapsulation in polymeric nanoparticles

Despite the fact that atrovastatin (At) is being one of the bestselling statins used to prevent complicated cardiovascular diseases, its low oral bioavailability decreases its clinical relevance. Herein, incorporation of At into ethylcellulose nanoparticles (At-NPs) was executed to test if it would enhance its oral bioavailability. The emulsification-evaporation method was used to prepare the At-NPs. The prepared nanoparticles were characterized by measuring the particle size, zeta potential as well as using FTIR, DSC, and XRD examination. The entrapment efficiency, drug content, and the in vitro release behavior of At-NPs were also examined. The in vivo oral bioavailability of the selected At-NPs formula was tested after being given orally to New Zealand rabbits. The nanoparticles obtained had a high drug content and a distinct spherical shape but with varying sizes. No physical or chemical interactions were detected between At and the nanoparticles as confirmed by FTIR, DSC, and XRD. The in vitro release study of At from the prepared At-NPs has shown nanoparticles size-dependent release behavior. The in vivo oral absorption testing confirmed the bioavailability of the prepared At-NPs to be as follows: (C_max = 940 ng/ml and AUC_0-12 = 8759 ng.h/ml) > Lipitor® (C_max = 635 ng/ml and AUC_0-12 = 4367 ng.h/ml) > At (C_max = 515 ng/ml and AUC_0-12 = 2517 ng.h/ml). These results revealed that the oral formula of At-NPs increases the bioavailability of At 3.87 times. This makes ethylcellulose nanoparticles an esteemed candidate nano-vehicle for At, increasing its bioavailability and thus improving its clinical relevance.

Does the trihydrate of atorvastatin calcium possess a melting point?

To decide whether an active pharmaceutical ingredient can be used in its amorphous form in drug formulations, often the glass transition is studied in relation to the melting point of the pharmaceutical. If the glass transition temperature is high enough and found relatively close to the melting point, the pharmaceutical is considered to be a good glass former. However, it is obviously important that the observed melting point and glass transition involve exactly the same system, otherwise the two temperatures cannot be compared. Although this may seem trivial, in the case of hydrates, where water may leave the system on heating, the composition of the system may not be evident. Atorvastatin calcium is a case in point, where confusing terminology, absence of a proper anhydrate form, and loss of water on heating lead to several doubtful conclusions in the literature. However, considering that no anhydrate crystal has ever been observed and that the glass transition of the anhydrous system is found at 144 °C, it can be concluded that if the system is kept isolated from water, the chances that atorvastatin calcium crystallises at room temperature is negligible. The paper discusses the various thermal effects of atorvastatin calcium on heating and proposes a tentative binary phase diagram with water.

Development of Poly (Methyl vinyl ether-alt-maleic acid) Microneedles for Transdermal Delivery of Atorvastatin Calcium

AIMS

Biodegradable polymeric microneedles containing atorvastatin calcium were developed in order to improve the percutaneous absorption of the drug, useful for the treatment of hypercholesterolemia.

BACKGROUND

The use of physical enhancers like microneedles have shown good results to increase the delivery of drugs through the skin, the use of microneedles has very important advantages for transdermal drug delivery, for example, they are painless, easy to use and safe, they increase time interval of drug activity, dose, and reductions in adverse reactions, they also offer, the facility to remove the system instantly of the skin.

OBJECTIVE

Develop polymer microneedles loaded with a calcium atorvastatin and evaluate them by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), bioadhesion, postwetting- bioadhesion, breaking strength, drug release test and in vitro percutaneous absorption studies to demonstrate the use of microneedles atorvastatin is able to cross the skin.

METHODS

The microneedles were made with poly (methyl vinyl ether-alt-maleic acid) as biodegradable polymer using the technique of casting in solution in a mold. After solidification these microneedles were characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), bioadhesion, post-wetting-bioadhesion, breaking strength, drug release test and in vitro percutaneous absorption studies.

RESULTS

In general, the performances were satisfactory for optimal formulation in terms of DSC with no interactions between drug and excipients, SEM shows microneedles with a conical shape, bioadhesion of 1570 g.f, post wetting-bioadhesion of 1503.4 g.f, breaking strength of 1566.7g.f that is sufficient to disrupt Stratum corneum, good drug release and a flux of 33.4 μg/cm2*h with a tLag of 15.14 h for the in vitro percutaneous absorption.

CONCLUSION

The results indicate that it is possible to generate microneedles to increase the percutaneous absorption of calcium atorvastatin transdermally, with the potential to be used as an alternative to the oral route for the treatment of dyslipidemias.

Effects of Polymer/Surfactant as Carriers on the Solubility and Dissolution of Fenofibrate Solid Dispersion

The purpose of this work is to investigate the effects of polymer/surfactant as carriers on the solubility and dissolution of fenofibrate solid dispersions (FF SDs) with the aid of systematic research on the physicochemical properties of the polymer/surfactant system and further highlight the importance of studying polymer/surfactant interaction in the preformulation. The critical micelle concentration (CMC) of sodium lauryl sulfate (SLS) and critical aggregation concentration (CAC) of polymer/SLS solutions were obtained through conductivity measurement. Meanwhile, surface tension, viscosity, morphology, and wettability of polymer/SLS with different weight ratios of SLS were analyzed to screen out the suitable content of SLS (weight%, 5% in carriers) incorporated in SDs. Polymer/SLS coprecipitate and FF SDs were prepared by the solvent evaporation method. The results from differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis showed that FF was molecularly dispersed in SDs. Compared to the solubility of FF in povidone/SLS (PVP/SLS) solutions, the increment of FF solubility in copovidone/SLS (VA64/SLS) solutions was due to the formation of free SLS micelles, which have been confirmed by transmission electron microscopy (TEM). Particularly, the wettability of FF SDs and physical mixtures (PMs) was also determined by the sessile drop technique. A linear relationship between the wettability of carriers and that of FF SDs was found, which revealed the significant role of carriers on the surface composition of FF SDs. As the molecular weight of PVP increased, the wettability of carriers decreased, thus leading to the reduction of the dissolution rate of SDs. Although the presence of SLS did not enhance the dissolution of FF SDs, it increased the amount of drug released at the initial stage. All these results indicated that the polymer/SLS interaction would affect the performance of SDs; hence, it was necessary to study their properties in the preformulation.

Interactions Between Paracetamol and Hypromellose in the Solid State

Hydroxypropyl methylcellulose (hypromellose) is a widely known excipient commonly used in the preparation of drug formulations. It can interact with some active pharmaceutical ingredients (APIs), thereby contributing to a reduction in crystallinity, serve as a solvent for API or form stable dispersion with no tendency to aggregation. The aim of the present study was to investigate the effect of hypromellose on the solubility, miscibility and amorphization of paracetamol in mixture with this polymer. Homogenized mixtures of paracetamol with hypromellose were studied using differential scanning calorimetry (DSC), hot-stage microscopy (HSM), Fourier transform infrared (FT-IR) and Raman methods to obtain a deeper insight into the interactions between ingredients in solid state including phase diagram construction for crystalline API and amorphous polymer. A DSC study revealed potential interaction between ingredients resulting in reduced paracetamol crystallinity. This was proved using heating-cooling-heating test to confirm paracetamol amorphization. FT-IR and Raman investigations excluded chemical reaction and hydrogen bonding between ingredients. The phase diagram developed facilitates predictions on the solubility of API in polymer, on the mutual miscibility of ingredients and on the temperature of mixture glass transition.

Atorvastatin calcium inclusion complexation with polysaccharide arabinogalactan and saponin disodium glycyrrhizate for increasing of solubility and bioavailability

The aim of the present investigation was to enhance the solubility and dissolution of atorvastatin calcium (ATV), a poorly water-soluble drug with larch polysaccharide arabinogalactan (AG) and disodium glycyrrhizate (Na₂GA) as carriers of drug delivery systems for improving its bioavailability. The interactions of ATV with AG or Na₂GA were investigated by DSC, XRD, SEM, and NMR techniques. The molecular weights of supramolecular systems-inclusion complexes and micelles-which are the hosts for ATV molecules were measured. On the other hand, the rapid storage assay (+ 40 °C for 3 months) showed that the chemical stability of ATV/AG and ATV/Na₂GA complexes had been enhanced compared with pure ATV. In vitro drug release showed a significant increase in ATV's dissolution rate after formation of a complex with Na₂GA or AG. Pharmacokinetic tests in vivo on laboratory animals showed a significant increase in ATV's bioavailability after its introduction as a complex with Na₂GA or AG. Moreover, ATV/AG and ATV/Na₂GA complexes showed a more prominent decrease of total cholesterol (TC) level compared to net ATV. Therefore, the novel mechanochemically synthesized complexes of ATV with AG or Na₂GA as drug delivery systems might be potential and promising candidates for hypercholesterolemia treatment and deserved further researches.

Preparation, characterization, and in vitro/vivo evaluation of polymer-assisting formulation of atorvastatin calcium based on solid dispersion technique

Due to low solubility and bioavailability, atorvastatin calcium is confronted with challenge in conceiving appropriate formulation. Solid dispersion of atorvastatin calcium was prepared through the solvent evaporation method, with Poloxamer 188 as hydrophilic carriers. This formulation was then characterized by scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction and fourier transform infrared spectroscopy. Moreover, all these studies suggested the conversion of crystalline atorvastatin calcium. In addition, the drug solubility studies as well as dissolution rates compared with bulk drug and market tablets Lipitor were also examined. Furthermore, the study investigated the pharmacokinetics after oral administration of Lipitor and solid dispersion. And the AUC_0–8 h and C_max increased after taking ATC-P188 solid dispersion orally compared with that of Lipitor. All these could be demonstrated that ATC-P188 solid dispersions would be prospective means for enhancing higher oral bioavailability of ATC.

Co-Amorphous Simvastatin-Nifedipine with Enhanced Solubility for Possible Use in Combination Therapy of Hypertension and Hypercholesterolemia

The high index of simultaneous incidence of hypertension and hypercholesterolemia in the population of many countries demands the preparation of more efficient drugs. Therefore, there is a significant area of opportunity to provide as many alternatives as possible to treat these illnesses. Taking advantage of the solubility enhancement that can be achieved when an active pharmaceutical ingredient (API) is obtained and stabilized in its amorphous state, in the present work, new drug-drug co-amorphous formulations (Simvastatin SIM- Nifedipine NIF) with enhanced solubility and stability were prepared and characterized. Results show that the co-amorphous system (molar ratio 1:1) is more soluble than the pure commercial APIs studied separately. Aqueous dissolution profiles showed increments of solubility of 3.7 and 1.7 times for SIM and NIF, correspondingly, in the co-amorphous system. The new co-amorphous formulations, monitored in time, (molar fractions 0.3, 0.5 and 0.7 of SIM) remained stable in the amorphous state for more than one year when stored at room temperature and did not show any signs of crystallization when re-heating. Inspection on the remainder of a sample after six hours of dissolution showed no recrystallization, confirming the stability of co-amorphous system. The enhanced solubility of the co-amorphous formulations makes them promising for simultaneously targeting of hypertension and hypercholesterolemia through combination therapy.

Effects of tablet formulation and subsequent film coating on the supersaturated dissolution behavior of amorphous solid dispersions

The effects of tablet preparation and subsequent film coating with amorphous solid dispersion (ASD) particles that were composed of a drug with poor water solubility and hydrophilic polymers were investigated. ASD particles were prepared with a drug and vinylpyrrolidone-vinyl acetate copolymer (PVPVA) or polyvinylpyrrolidone (PVP) at a weight ratio of 1:1 or 1:2 using a melt extrusion technique. Tablets were prepared by conventional direct compression followed by pan coating. A mathematical model based on the Noyes-Whitney equation assuming that stable crystals precipitated at the changeable surface area of the solid-liquid interface used to estimate drug dissolution kinetics in a non-sink dissolution condition. All the ASD particles showed a maximum dissolution concentration approximately ten times higher than that of the crystalline drug. The ASD particles with PVPVA showed higher precipitation rate with lower polymer ratio, while PVP did not precipitate within 960 min regardless of the polymer ratio, suggesting the ASD particles of 1:1 drug:PVPVA (ASD-1) were the most unstable among the ASD particles considered. The dissolution of a core tablet with ASD-1 showed less supersaturation and a much higher precipitation rate than those of ASD-1 particles. However, a film-coated tablet or core tablet with a trace amount of hydroxypropylmethylcellulose (HPMC) showed a similar dissolution profile to that of the ASD-1 particles, indicating HPMC had a remarkable precipitation inhibition effect. Overall, these results suggest that tablet preparation with ASD may adversely affect the maintenance of supersaturation; however, this effect can be mitigated by adding an appropriate precipitation inhibitor to the formulation.

Physicochemical characterization of atorvastatin calcium/ezetimibe amorphous nano-solid dispersions prepared by electrospraying method

In the present study, electrospraying was applied as a novel method for the fabrication of amorphous nano-solid dispersions (N-SDs) of atorvastatin calcium (ATV), ezetimibe (EZT), and ATV/EZT combination as poorly water-soluble drugs. N-SDs were prepared using polyvinylpyrrolidone K30 as an amorphous carrier in 1:1 and 1:5 drug to polymer ratios and the total solid (including drug and polymer) concentrations of 10 and 20% (w/v). The prepared formulations were further investigated for their morphological, physicochemical, and dissolution properties. Scanning electron microscopy studies indicated that the morphology and diameter of the electrosprayed samples (ESs) were influenced by the solution concentration and drug:polymer ratio, so that an increase in the solution concentration resulted in fiber formation while an increase in the polymer ratio led to enhancement of the particle diameter. Differential scanning calorimetry and X-ray powder diffraction studies together with in vitro dissolution test revealed that the ESs were present in an amorphous form with improved dissolution properties. Infrared spectroscopic studies showed hydrogen-bonding interaction between the drug and polymer in ESs. Since the electrospraying method benefits from the both amorphization and nanosizing effect, this novel approach seems to be an efficient method for the fabrication of N-SDs of poorly water-soluble drugs.

Polymeric behavior evaluation of PVP K30-poloxamer binary carrier for solid dispersed nisoldipine by experimental design

CONTEXT

High melting point polymeric carrier without plasticizer is unacceptable for solid dispersion (SD) by melting method. Combined polymer-plasticizer carrier significantly affects drug solubility and tableting property of SD.

OBJECTIVE

To evaluate and optimize the combined effect of a binary carrier consisting PVP K30 and poloxamer 188, on nisoldipine solubility and tensile strength of amorphous SD compact (SD_compact) by experimental design.

MATERIALS AND METHODS

SD of nisoldpine (SD_nisol) was prepared by melt mixing with different PVP K30 and poloxamer amount. A 3² factorial design was employed using nisoldipine solubility and tensile strength of SD_compact as response variables. Statistical optimization by design expert software, and SD_nisol characterization using ATR FTIR, DSC and microscopy were done.

RESULTS

PVP K30:poloxamer, at a ratio of 3.73:6.63, was selected as the optimized combination of binary polymeric carrier resulting nisoldipine solubility of 115 μg/mL and tensile strength of 1.19 N/m².

DISCUSSION

PVP K30 had significant positive effect on both responses. Increase in poloxamer concentration after a certain level decreased nisoldipine solubility and tensile strength of SD_compact.

CONCLUSION

An optimized PVP K30-poloxamer binary composition for SD carrier was developed. Tensile strength of SD_compact can be considered as a response for experimental design to optimize SD.