Solubility enhancement of desloratadine by solid dispersion in poloxamers

The present study investigates the possibility of using poloxamers as solubility and dissolution rate enhancing agents of the poorly water soluble drug substance desloratadine that can be used for the preparation of immediate release tablet formulation. Two commercially available poloxamer grades (poloxamer P 188 and poloxamer P 407) were selected, and solid dispersions (SDs) containing different weight ratio of poloxamers and desloratadine were prepared by a low temperature melting method. All SDs were subjected to basic physicochemical characterization by thermal and vibrational spectroscopy methods in order to evaluate the efficiency of poloxamers as solubility enhancers. Immediate release tablets were prepared by direct compression of powdered solid dispersions according to a General Factorial Design, in order to evaluate the statistical significance of two formulation (X(1) - type of poloxamer in SD and X(2) - poloxamer ratio in SD) and one process variable (X(3) - compression force) on the drug dissolution rate. It was found that desloratadine in SDs existed in the amorphous state, and that can be largely responsible for the enhanced intrinsic solubility, which was more pronounced in SDs containing poloxamer 188. Statistical analysis of the factorial design revealed that both investigated formulation variables exert a significant effect on the drug dissolution rate. Increased poloxamer ratio in SDs resulted in increased drug dissolution rate, with poloxamer 188 contributing to a faster dissolution rate than poloxamer 407, in accordance with the results of intrinsic dissolution tests. Moreover, there is a significant interaction between poloxamer ratio in SD and compression force. Higher poloxamer ratio in SDs and higher compression force results in a significant decrease of the drug dissolution rate, which can be attributed to the lower porosity of the tablets and more pronounced bonding between poloxamer particles.     

Improved pH-independent dissolution and oral absorption of valsartan via the preparation of solid dispersion

This study aimed to improve the pH-independent solubility and dissolution characteristics of valsartan via the preparation of solid dispersions (SD) with poloxamer 407. SDs was prepared by using the solvent method at various drug-polymer ratios and their dissolution characteristics were examined at different pHs. Oral pharmacokinetics of SDs was also evaluated in rats. Compared to the untreated powder, SDs significantly improved the dissolution rate as well as the extent of drug release at low pH. Particularly, SD having the drug-polymer ratio of 1:5 exhibited pH-independent dissolution of valsartan, resulting in the rapid and complete drug release over the pH range of 1.2 to 6.8. The improved dissolution of valsartan via SD formulation appeared to be well correlated with the enhanced oral exposure of valsartan in rats. SDs increased C_max and AUC_0–24 of valsartan by 2–7 folds in rats, implying that SDs should be effective to improve the bioavailability of valsartan. In conclusion, SDs containing poloxamer 407 appeared to be effective to improve the pH-independent dissolution and oral absorption of valsartan.     

Formulation and in vivo hypoglycemic effect of glipizide solid dispersion

The present study was carried out with a view to enhance dissolution rate of poorly water-soluble drug glipizide (GZ) (BCS class II) using polyethylene glycol (PEG) 6000, PEG 8000 and poloxamer (PXM) 188 as carriers. Solid dispersions (SDs) were prepared by melting method using different ratios of glipizide to carriers. Phase solubility study was conducted to evaluate the effect of carrier on aqueous solubility of glipizide. SD was optimized by drug content estimation and in vitro dissolution study and optimised SD was subjected to bulk characterization, Scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and X-ray diffraction study (XRD). Preclinical study was performed in mice to study the decrease in blood glucose level from prepared SD compared with pure drug. Due to high solubility and drug release, PXM 188 in weight ratio of 1:2 was optimized. Decrease in blood glucose level in mice from SD was significantly higher (p < 0.05) compared to pure glipizide. Thus, solid dispersion technique can be successfully used for the improvement of the dissolution profile of GZ.     

Study on solubility improvement of lidocaine by ternary solid dispersion

In the present study, we aimed to probe the possibility of using mixed poloxamers as carriers to prepare ternary solid dispersion (SD) that facilitated solubility and dissolution rate of the poorly water soluble drug and compare with binary SD with single poloxamer. Lidocaine (LIC) was selected as a model drug, and poloxamer 188 (P188) and poloxamer 407 (P407) were utilized as single and mixed carriers. Depending on DSC and the dissolution testing, the appropriate ratio of SD prepared by melting method was optimized. Ternary and binary SD was characterized by DSC, XRD, SEM and FTIR. In vitro dissolution study, phase solubility study and saturated solubility study were performed to clarify solubilization from apparent phenomena and inherent reason. Moreover, stability study under different relative humidity (RH) was investigated. Physical characterizations of binary and ternary SD exhibited the formation of eutectic mixture and the presence of molecular interaction. Compared with the pure LIC, the dissolution rate and solubility of LIC in binary and ternary SDs were enhanced. The phase solubility study revealed an AL-type curve. Furthermore, the stability test indicated that ternary and binary SD was stable. The results of this study demonstrated that SD with mixed poloxamers could improve dissolution rate and solubility of poorly water-soluble drug.     

Improvement in Dissolution Rate of Cefuroxime Axetil by using Poloxamer 188 and Neusilin US2

A combination of fusion and surface adsorption techniques was used to enhance the dissolution rate of cefuroxime axetil. Solid dispersions of cefuroxime axetil were prepared by two methods, namely fusion method using poloxamer 188 alone and combination of poloxamer 188 and Neusilin US2 by fusion and surface adsorption method. Solid dispersions were evaluated for solubility, phase solubility, flowability, compressibility, Kawakita analysis, Fourier transform-infrared spectra, differential scanning calorimetry, powder X-ray diffraction study, in vitro drug release, and stability study. Solubility studies showed 12- and 14-fold increase in solubility for solid dispersions by fusion method, and fusion and surface adsorption method, respectively. Phase solubility studies showed negative ΔG⁰_tr values for poloxamer 188 at various concentrations (0, 0.25, 0.5, 0.75 and 1%) indicating spontaneous nature of solubilisation. Fourier transform-infrared spectra and differential scanning calorimetry spectra showed that drug and excipients are compatible with each other. Powder X-ray diffraction study studies indicated that presence of Neusilin US2 is less likely to promote the reversion of the amorphous cefuroxime axetil to crystalline state. in vitro dissolution studies, T50% and mean dissolution time have shown better dissolution rate for solid dispersions by fusion and surface adsorption method. Cefuroxime axetil release at 15 min (Q15) and DE15 exhibited 23- and 20-fold improvement in dissolution rate. The optimized solid dispersion formulation was stable for 6 months of stability study as per ICH guidelines. The stability was ascertained from drug content, in vitro dissolution, Fourier transform-infrared spectra and differential scanning calorimetry study. Hence, this combined approach of fusion and surface adsorption can be used successfully to improve the dissolution rate of poorly soluble biopharmaceutical classification system class II drug cefuroxime axetil.     

Molecular Mechanisms Involved in Supersaturation of Emodin Ternary Solid Dispersions Based on Bonding Agents

The use of solid dispersions (SDs) is an established method for improving the dissolution rate of poorly water-soluble drugs. However, there have been few studies on the molecular mechanisms contributing to SD supersaturation. Emodin ternary SDs (TSDs) were prepared by hot melt extrusion (HME) using Kollidon® VA64 as the polymer carrier and nicotinamide as the bonding agent. Molecular docking and solubility tests were used to assist screening of polymer carriers, and in vitro dissolution and dissociation constant data were used to optimize the formulation. A variety of analytical methods and molecular dynamics simulations were used to investigate the mechanism of SD supersaturation at the molecular level. The results showed that molecular migration, intermolecular interactions, drug crystal transformation and dissociation constant were particularly important factors in SD supersaturation. This study proposes a new strategy to improve solubility of poorly water-soluble drugs and explore the molecular mechanisms of TSD supersaturation, which could provide a basis for the rational selection of excipients for pharmaceutical preparations.     

Dissolution enhancement of felodipine by amorphous nanodispersions using an amphiphilic polymer: insight into the role of drug–polymer interactions on drug dissolution

Context: Felodipine, a poorly soluble drug, is widely used in the treatment of angina pectoris and hypertension.

Objective: This study aimed at the preparation of amorphous solid dispersion (SD) of felodipine using an amphiphilic polymer, soluplus, for the potential enhancement in solubility of the drug.

Materials and methods: Solid dispersions with varying proportions of drug and soluplus were prepared and the rate and extent of dissolution from SDs was compared with that of the pure drug. FT-IR and ¹H NMR spectroscopic analysis were carried out to examine the formation mechanism of SDs. Various techniques were used for solid state characterization of designed SDs.

Results: Formation of amorphous solid dispersions with particle size in nanometer range indicated suitability of polymer and method used in the preparation. FT-IR and ¹H NMR spectroscopy revealed that soluplus was involved in strong hydrogen bonding with felodipine molecules which resulted in the conversion of crystalline felodipine into amorphous form. Solid dispersion with 1:10 drug/polymer ratio showed more than 90% drug dissolution in 30?min whereas pure felodipine showed less than 19% drug dissolution in 1?h.

Discussion and conclusion: Amorphous SDs of felodipine were prepared using soluplus resulting in substantial enhancement in the rate and extent of dissolution of felodipine.     

Solid dispersions: a strategy for poorly aqueous soluble drugs and technology updates

Introduction: Present article reviews solid dispersion (SD) technologies and other patented inventions in the area of pharmaceutical SDs, which provide stable amorphous SDs.

Areas covered: The review briefly compiles different techniques for preparing SDs, their applications, characterization of SDs, types of SDs and also elaborates the carriers used to prepare SDs. The advantages of recently introduced SD technologies such as RightSize^?, closed-cycle spray drying (CSD), Lidose® are summarized. Stability-related issues like phase separation, re-crystallization and methods to curb these problems are also discussed. A patented carrier-screening tool for predicting physical stability of SDs on the basis of drug–carrier interaction is explained. Applications of SD technique in controlled drug delivery systems and cosmetics are explored. Review also summarizes the carriers such as Soluplus®, Neusilin®, Solumer^TM used to prepare stable amorphous SD.

Expert opinion: Binary and ternary SDs are found to be more stable and provide better enhancement of solubility or dissolution of poorly water-soluble drugs. The use of surfactants in the carrier system of SD is a recent trend. Surfactants and polymers provide stability against re-crystallization of SDs, surfactants also improve solubility and dissolution of drug.     

Enhanced dissolution and oral bioavailability of valsartan solid dispersions prepared by a freeze-drying technique using hydrophilic polymers

This study aimed to improve the dissolution rate and oral bioavailability of valsartan (VAL), a poorly soluble drug using solid dispersions (SDs). The SDs were prepared by a freeze-drying technique with polyethylene glycol 6000 (PEG6000) and hydroxypropylmethylcellulose (HPMC 100KV) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant without using any organic solvents. In vitro dissolution rate and physicochemical properties of the SDs were characterized using the USP paddle method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and Fourier transform-infrared (FT-IR) spectroscopy, respectively. In addition, the oral bioavailability of SDs in rats was evaluated by using VAL (pure drug) as a reference. The dissolution rates of the SDs were significantly improved at pH 1.2 and pH 6.8 compared to those of the pure drug. The results from DSC, XRD showed that VAL was molecularly dispersed in the SDs as an amorphous form. The FT-IR results suggested that intermolecular hydrogen bonding had formed between VAL and its carriers. The SDs exhibited significantly higher values of AUC_0–24?h and C_max in comparison with the pure drug. In conclusion, hydrophilic polymer-based SDs prepared by a freeze-drying technique can be a promising method to enhance dissolution rate and oral bioavailability of VAL.     

Enhancement of solubility and dissolution of Coenzyme Q10 using solid dispersion formulation

This study aimed to develop a stable solid dispersion of Coenzyme Q₁₀ (CoQ₁₀) with high aqueous solubility and dissolution rate. Among various carriers screened, poloxamer 407 was most effective to form a superior solid dispersion of CoQ₁₀ having significantly enhanced solubility. Particularly, solid dispersion of CoQ₁₀ with poloxamer 407 in the weight ratio of 1:5 prepared by melting method enhanced the solubility of CoQ₁₀ to the greatest extent. However, it exhibited poor stability and hence Aerosil^® 200 (colloidal silicon dioxide) was incorporated into the solid dispersion as an adsorbent to inhibit the recrystallization process. The solid dispersion of CoQ₁₀, poloxamer 407 and Aerosil^® 200 in the weight ratio of 1:5:6 exhibited improved stability with no significant change in solubility during the 1-month stability test. Moreover, the solid dispersion formulation containing Aerosil^® 200 significantly enhanced the extent of drug release (approx. 75% release) as well as the dissolution rate of CoQ₁₀. In conclusion, the present study has developed the stable solid dispersion formulation of CoQ₁₀ with poloxamer 407 and Aerosil^® 200 for the enhanced solubility and dissolution of CoQ₁₀, which could also offer some additional advantages including ease of preparation, good flowability and cost-effectiveness.     

Enhanced solubility and permeability of exemestane solid dispersion powders for improved oral delivery

The aim of the present investigation was to enhance the solubility of exemestane (EXM), by solid dispersion (SD) technique using PEG 6000 as a carrier. Phase solubility studies were conducted with PEG 6000 and PEG 20000 to evaluate the effect of carriers on aqueous solubility of EXM. The aqueous solubility of EXM was favoured with PEG 6000 compared to PEG 20000. SDs of EXM using polyethylene glycol 6000 (PEG 6000) as carrier were prepared in different drug to carrier ratios. Solid-state characterization indicated decrease in crystallinity of the drug. The in vitro dissolution rate of EXM was enhanced from both SDs and tablet formulations prepared using SD compared to pure EXM. The in situ permeability studies investigated using single-pass intestinal perfusion technique in rats revealed increase in effective intestinal permeability (P_eff, cm/s) by 4.45 folds with SDs. Thus, EXM-PEG 6000 SDs showed improved solubility and permeability.     

Improvement of solubility,dissolution and stability profile of artemether solid dispersions and self emulsified solid dispersions by solvent evaporation method

Abstract

The purpose of this study was to investigate changes in the water solubility of artemether; a poorly soluble drug used for the treatment of malaria. Different solid dispersions (SDs) of artemether were prepared using artemether and polyethylene glycol 6000 at ratio 12:88 (Group 1), self-emulsified solid dispersions (SESDs) containing artemether, polyethylene glycol 6000, cremophor-A-25, olive oil, hydroxypropylmethylcellulose and transcutol in the ratio 12:75:5:4:2:2, respectively (Group 2). SESDs were also prepared by substituting cremophor-A-25 in Group 2 with poloxamer 188 (noted as Group 3). Each of these preparations was formulated using physical mixing and the solvent evaporation method. Aqueous solubility of artemether improved 11-, 95- and 102-fold, while dissolution (in simulated gastric fluid) increased 3-, 13- and 14-fold, for formulation groups 1, 2 and 3, respectively. X-ray diffraction patterns of SDs indicated a decrease in peak intensities at 10° implying reduced artemether crystallinity. Scanning electron micrographs invariably revealed embedment of artemether by various excipients and a glassy appearance for solvent evaporated mixtures for all three formulation Groups. Our findings indicate improved hydrophilic interactions for drug particles yield greater solubility and dissolution in the following order for artemether formulating methods: solvent evaporation mixtures?>?physical mixtures?>?pure artemether.     

Preparation and Evaluation of Palm Oil-Based Polyesteramide Solid Dispersion for Obtaining Improved and Targeted Dissolution of Mefenamic Acid

Purpose

The aim of this work was to investigate the functional role of newly synthesised palm oil-based polyesteramide (POPEA) and stearic acid-based polyesteramide (SAPEA) in mefenamic acid (MA) solid dispersion (SD).

Methods

Solid dispersions of MA were prepared by hot melt method, using a combination of POPEA/SAPEA as a polymer carrier. The effects of POPEA/SAPEA mixture ratio, drug loading percentage and influence of different Mw of POPEA (4000–17,000 Da) in SD were investigated. The SDs were characterised for drug content, solubility, dissolution behaviour and physico-chemical characteristics by DSC and FTIR. Comparisons were made with pure drug, physical mixture and a marketed MA formulation.

Results

All SDs demonstrated faster dissolution rate than pure MA and SD 6 formulated with SAPEA/POPEA 4000 Da, 8:2 showed the highest T ₅₀ release rate (45 min) with no significant difference (P?>?0.05) compared to marketed formulation. All SDs showed improved drug release (85.48?±?1.17 to 90.66?±?1.53%) against marketed formulation (81.30?±?1.26%) and MA (56.27?±?1.08%) after 6 h of dissolution. DSC endothermic peak for MA in SD 6 was broadened and shifted to lower temperature (194 °C). FTIR spectroscopy confirmed no chemical changes in MA SD, but establishment of hydrogen bonding between hydroxyl groups of PEA with amine groups of MA was observed by the red shift of OH band in SD samples. The SD was stable (P?>?0.05) at ambient condition for up to 90 days, reflecting by the drug content, dissolution profiles and solubility of the formulation.

Conclusions

POPEA demonstrated surface lowering and wettability effects in improving the aqueous solubility and dissolution rate of MA in SD. The crystalline drug was transformed to amorphous formulation, via solubilisation and crystallisation inhibition effect of the PEA.

     

Extruded Soluplus/SIM as an oral delivery system: characterization,interactions, in vitro and in vivo evaluations

Abstract

The aim of this study was to obtain a stable, amorphous solid dispersion (SD) with Soluplus, prepared by hot-melt extrusion (HME) as an effective and stable oral delivery system to improve the physical stability and bioavailability of the poorly water-soluble simvastatin (SIM), a drug with relatively low Tg. The drug was proved to be miscible with Soluplus by calculation and measurements. The solubility, dissolution, thermal characteristics, interactions and physical stability of the SIM/Soluplus SDs were investigated. The crystal state of simvastatin in the SD was found to change from crystalline to amorphous form during the HME process and also hydrogen bonds were observed between SIM and the extruded Soluplus. The phase solubility showed the solubilization effect of Soluplus was strong and spontaneous. The equilibrium solubility illustrated that Soluplus/SIM SDs gained much higher solubility than its corresponding physical mixtures (PMs). Both of the dissolution profiles and in-vivo performance showed that the SIM/Soluplus SD obtained a marked enhancement, compared with the PM. There was a little change in the SIM/Soluplus SD during a 3-month storage period (40?°C, 75%), indicating the good physicochemical stability. The extruded Soluplus system prepared by HME is a good alternative for the water-insoluble SIM to improve the stability and bioavailability.     

In vitro dissolution study of acetylsalicylic acid solid dispersions. Tunable drug release allowed by the choice of polymer matrix

Abstract

Due to their high versatility and diverse excipient options, solid dispersions (SDs) are an elegant choice for the formulation of active pharmaceutical ingredients with inconvenient solubility. Four distinct types of polymers with different physicochemical properties [polyvinylpyrrolidone, poly[N-(2-hydroxypropyl)-metacrylamide], poly(2-ethyl-2-oxazoline), and polyethylene glycol] and variable molecular weights were compared to investigate the influence of the polymer matrix on drug release. To probe the extent of intercomponent interactions, acetylsalicylic acid (ASA) was used as a model active substance. Controlled drug release was demonstrated for all four types of polymer-ASA SDs created by the freeze-drying method. While the polyethylene glycol-ASA SD exhibited an increased dissolution rate, the other polymer-ASA systems exhibited significantly reduced drug dissolution kinetics compared to free ASA. Furthermore, in contrast to physical mixtures, the prepared SDs all exhibited zero-order dissolution kinetics for ASA. The dissolution rate was strongly dependent on the molecular weight of the polymer. These results demonstrate that the type of SD may be controlled by the chemical constitutions of the polymers and that appropriate selection of the molecular weight of the polymer matrix enables finely tuned drug release over a wide range of dissolution rates.     

Preparation and Evaluation of Fast Dissolving Ibuprofen-Polyethylene Glycol 6000 Solid Dispersions

To improve its oral absorption, rapidly dissolving ibuprofen solid dispersions (SD) were prepared in a relatively easy, simple, quick, inexpensive, and reproducible manner, characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). They were evaluated for solubility, in vitro release, and oral bioavailability of ibuprofen in rats. Loss of individual surface properties during melting and resolidification as revealed by SEM indicated the formation of effective SDs. Absence or shifting toward the lower melting temperature of the drug peak in SDs and physical mixtures in DSC study indicated the possibilities of drug-polymer interactions. However, no such interactions in the solid state were confirmed by FTIR spectra that showed the presence of drug crystalline in SDs. Quicker release of ibuprofen from SDs in rat intestine resulted in a significant increase in AUC and C_max, and a significant decrease in T_max over pure ibuprofen. Preliminary results from this study suggested that the preparation of fast-dissolving ibuprofen SDs by low temperature melting method using PEG 6000 as a meltable hydrophilic polymer carrier could be a promising approach to improve solubility, dissolution, and absorption rate of ibuprofen.     

Enhancement of solubility and dissolution rate of cryptotanshinone, tanshinone I and tanshinone IIA extracted from Salvia miltiorrhiza

Cryptotanshinone, tanshinone I and tanshinone IIA are three major components in the extract of Salvia miltiorrhiza with pharmacological significance. However, their effective utilization is limited due to poor water solubility and bioavailability. Solid dispersion (SD) of the extract of Salvia miltiorrhiza was prepared to enhance solubility and dissolution of the three major components. Various carriers were screened for SD preparation by conventional solvent method. Dissolution of the components from selected SD systems was compared with commercial tablets of the extract from Salvia miltiorrhiza. The solubility of three components viz., cryptotanshinone, tanshinone I and tanshinone IIA, after forming SD with either of povidone K-30 (PVP K-30) or poloxamer 407, exhibited enhanced solubility in pH 6.8 buffer. Dissolution test revealed that the amount of three components released was higher from SD tablets as compared to the commercial tablets. Pharmacokinetic profile was evaluated using cryptotanshinone as a representative compound. AUC of cryptotanshinone was significantly increased when administered as a solid dispersion.     

Enhancement of Solubility and Dissolution Rate of Loratadine with Gelucire 50/13

The objective of the current investigation was to enhance the solubility and dissolution rate of loratadine using solid dispersions (SDs) with Gelucire 50/13. SDs of loratadine using Gelucire 50/13 as carrier were prepared by the solvent evaporation method, characterized for drug content, dissolution behavior, and physicochemical characteristics by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) studies. At 10 % concentration of Gelucire 50/13, the increase in solubility was around 100-fold compared with pure drug. The solubility of loratadine in the presence of Gelucire 50/13 in water showed linear increase with increasing concentrations of Gelucire indicating A_L-type solubility diagrams. The mean dissolution time (MDT) of loratadine decreased after preparation of SDs with Gelucire 50/13 indicating increased dissolution rate. FTIR studies showed the stability of loratadine and the absence of a well-defined interaction. DSC and XRD studies revealed the amorphous state of loratadine in SDs which was further confirmed from SEM. From the dissolution parameters, it is evident that the solubility and dissolution rate of loratadine was enhanced by SDs with Gelucire 50/13.     

The Impact of Solid Dispersion on Formulation,Using Confocal Micro Raman Spectroscopy as Tool to Probe Distribution of Components

Purpose

Solid dispersions (SDs) of a poorly water-soluble drug were prepared, and their physicochemical properties were compared to those of control physical mixtures (PMs). Among the multiple techniques used to characterize the solid state of preparations, confocal micro Raman spectroscopy (CMRS) was used as a non-destructive tool to qualitatively probe content uniformity and distribution of drug and carrier.

Methods

SDs and PMs of drug (fenbendazole, FBZ) were prepared containing two different carriers (poloxamer P188 or P407) with different drug polymer ratios. The preparations were characterized by powder X-ray diffractometry, Fourier transform infrared spectroscopy, thermal analysis, scanning electron microscopy, and in vitro dissolution assay. In addition, CMRS technique and principal component analysis (PCA) were used in order to statistically define the content uniformity and distribution of the drug within the polymeric matrix.

Results

In vitro dissolution results exhibited a marked improvement when the drug was formulated as SD compared to control PM and to pure drug. The solid state of these preparations characterized by X-ray powder diffraction and Fourier transform infrared spectroscopy showed no changes in the crystalline state of the drug and no chemical interactions between the components. Raman studies showed a better content uniformity of the drug within the polymeric matrix when subjected to SD process, correlating with the improved dissolution profile.

Conclusion

This study provides evidence of the potential of the confocal Raman imaging technique, providing a fast and powerful method to characterize solid dispersions which could be incorporated towards the use of quality by design (QbD) approaches in pharmaceutical development.

     

Preparation and characterisation of lornoxicam solid dispersion systems using hot melt extrusion technique

The aim of the research study was to investigate the ability of Soluplus^® and surfactant individually as well as in combination to improve the solubility, subsequently the dissolution profile of lornoxicam (LORX). A laboratory size single screw rotating extruder with temperature and speed control parameters employed during hot melt extrusion (HME) processing of LORX along with polymer-surfactant blends. Soluplus^® used as primary solubilizing agent for preparing solid dispersion (SD). Along with Soluplus^® different concentrations of surfactants such as PEG 400, Lutrol F127, Lutrol F68 were used to solve the permeability issues related to LORX. Encapsulation of LORX particles inside the molten matrix of polymer-excipient blend was confirmed by DSC, XRD and FT-IR. Drug excipient microscopic interaction was further confirmed by scanning electron microscopy (SEM). Depending upon the ratio of the polymer and surfactants used, the solubility of the hot melt extruded LORX was improved and found to be in the range 35–86 μg/ml (actual aqueous solubility of LORX was found to be 0.0083 μg/ml). Dissolution profile of the extruded SD was improved and was found to be in the range of 98–104 % within 20 min (actual dissolution profile of LORX was found to be 8 % at the end of 1 h). SEM and Raman images suggest the formation of amorphous dispersion systems. SD was subjected to stability studies as per ICH guidelines and found to be stable after 6 months when analyzed by HPLC. SD prepared from HME significantly improves the solubility and dissolution profile of LORX—a BCS class II drug.