Preparation and, in vitro, preclinical and clinical studies of aceclofenac spherical agglomerates

Processability and Oral Bioavailability Improvement of Itraconazole by Particle Engineering Technique

The current study aimed to improve the processability and oral bioavailability of itraconazole (ITZ) via spherical agglomeration. ITZ-spherical agglomerates (ITZ-SA) and ITZ-poloxamer 407-spherical agglomerates (ITZ-PLX-SA) were optimized using Box-Behnken design. Here, the drug release was affected by polymer concentration and stirring speed, whereas particle size was altered by stirring speed, polymer concentration, and amount of bridging liquid. Heckel and Kawakita studies showed a reduction in mean yield pressure and remarkably lowered 1/b value than ITZ, indicating better compactibility and flowability of ITZ-PLX-SA. Physicochemical interactions were not observed during the process, as indicated by ATR-FTIR, DSC, and XRPD. The significant improvement in % drug release of ITZ-PLX-SA was attributed to better wettability and the presence of polymer than ITZ-SA and ITZ. The pharmacokinetic study in rats indicated fivefold enhanced Cmax and twofold improved AUC for ITZ-PLX-SA than plain drug. Thus, spherical agglomeration could improve overall processability and pharmacokinetic profile of ITZ.

Effect Of Surfactant Chain Length On Emulsification Dynamics Of Self Emulsifying Formulation Of Poorly Soluble Drug

AIM

In this work the aim was to study the chain length of surfactant on the self emulsifying system of a poorly soluble drug, aceclofenac. The selection of almond oil as a lipid vehicle was done on basis of solubility and compatibility of the vehicle with the drug.

METHODS

The effect of varying chain length of different surfactants of Tween series namely Tween 20, Tween 40, Tween 60 and Tween 80 was evaluated on self emulsifying efficiency by constructing pseudoternary diagrams. PEG-400 was used as co-surfactant in a definite ratio with all the surfactants to minimize their concentration. The best self emulsifying ability was exhibited by Tween 80: PEG-400 combination followed by Tween 60: PEG-400, Tween 40: PEG-400, Tween 20: PEG-400. This observation indicates that as the chain length of Tweens increases their ability to form a good microemulsion increases if same co-surfactant is used.

RESULTS

However it has also been found that the presence of unsaturated bond in Tween 80 provides it an elasticity which supports good intermixing of oil and water and leading to formation of a fine microemulsion. Six different formulations were prepared using combination of almond oil, Tween 80, PEG-400 and the drug aceclofenac.

CONCLUSION

The formulations were subjected to various evaluation parameters such as dispersibility, transmittance, pH, globule size, polydispersibility, zeta potential, viscosity, refractive index and in vitro dissolution. The best formulation was found to have globule size of less than 100 nm, zeta potential of -3.35 ± 0.60 mV which indicates formation of a microemulsion of aceclofenac with good stability.

Physicomechanical, stability, and pharmacokinetic evaluation of aceclofenac dimethyl urea cocrystals

Poor physicomechanical properties and limited aqueous solubility restrict the bioavailability of aceclofenac when given orally. To improve its above properties, aceclofenac (ACE) was cocrystallized with dimethyl urea (DMU) in 1:2 molar ratio by dry and solvent assisted grinding. The cocrystals were characterized by ATR-FTIR, DSC, and PXRD, and their surface morphology was studied by SEM. There was enhancement in intrinsic dissolution rate (IDR) (~eight- and ~fivefold in cocrystals prepared by solvent assisted grinding (SAG) and solid state grinding (SSG), respectively, in 0.1 N HCl, pH 1.2) and similarly (~3.42-fold and ~1.20-fold in phosphate buffer, pH 7.4) as compared to pure drug. Additionally, mechanical properties were assessed by tabletability curves. The tensile strength of ACE was < 1 MPa in contrast to the cocrystal tensile strength (3.5 MPa) which was ~1.98 times higher at 6000 psi. The tablet formulation of cocrystal by direct compression displayed enhanced dissolution profile (~36% in 0.1 N HCl, pH 1.2, and ~100% in phosphate buffer, pH 7.4) in comparison to physical mixture (~ 30% and ~ 80%) and ACE (~18% and ~50%) after 60 min, respectively. Stability studies of cocrystal tablets for 3 months indicated a stable formulation. Pharmacokinetic studies were performed by using rabbit model. The AUC_0-∞ (37.87±1.3 μgh/ml) and C_max (6.94±2.94 μg/ml) of the selected cocrystal C1 prepared by SAG were significantly enhanced (p < 0.05) and were ~3.43 and ~1.63-fold higher than that of ACE. In conclusion, new cocrystal of ACE-DMU was successfully prepared with improved tabletability, in vitro and in vivo properties.

In situ composite ion-triggered gellan gum gel incorporating amino methacrylate copolymer microparticles: a therapeutic modality for buccal applicability

The aim of the current investigation is to delineate the buccal applicability of an in situ composite gel containing aceclofenac (AC) amino methacrylate copolymer microparticles (MPs), surmounting limitations of oral existing conventional therapy. AC Eudragit RL100 MPs were fabricated and statistically optimized using 2²4¹ factorial design. Better buccal applicability and enhanced localization were achieved by combining the optimum MPs with in situ ion-activated gellan gum gel. The crosslinking and gelation of in situ gel were investigated by morphological and solid state characterizations. Suitability for buccal delivery and in vivo therapeutic efficacy in inflammation model of rats were also assessed. Results showed that the best performing formula displayed particle size (PS) of 51.00 µm and high entrapment efficiency (EE%) of 94.73%. MPs were successfully entrapped inside the gel network of the composite system. Gelation tendency, pH, shear-thinning properties and mucoadhesivity of the prepared in situ composite gel guaranteed its buccal suitability. Sustained AC release features and promising in vitro anti-arthritic response were also demonstrated. Moreover, consistent and prolonged in vivo anti-inflammatory effect was achieved, relative to standard AC. Taken together; this study proves the potential of in situ composite gel as an appropriate therapeutic proposal for AC buccal delivery.

The Impact of Amorphisation and Spheronization Techniques on the Improved in Vitro & in Vivo Performance of Glimepiride Tablets

Purpose: Triple solid dispersion adsorbates (TSDads) and spherical agglomerates (SA) present new techniques that extensively enhance dissolution of poorly soluble drugs. The aim of the present study is to hasten the onset of hypoglycemic effect of glimepiride through enhancing its rate of release from tablet formulation prepared from either technique.

Methods: Drug release from TSDads or SA tablets with different added excipients was explored. Scanning electron microscopy (SEM) and effect of compression on dissolution were illustrated. Pharmacodynamic evaluation was performed on optimized tablets.

Results: TSDads & SA tablets with Cross Povidone showed least disintegration times of 1.48 and 0.5 min. respectively. Kinetics of drug release recorded least half-lives (54.13 and 59.83min for both techniques respectively). Cross section in tablets displayed an organized interconnected matrix under SEM, accounting for the rapid access of dissolution media to the tablet core. Components of tablets filled into capsules showed a similar release profile to that of tablets after compression as indicated by similarity factor. The onset time of maximum reduction in blood glucose in male albino rabbits was hastened to 2h instead of 3h for commercial tablets.

Conclusion: After optimization of tablet excipients that interacted differently with respect to their effect on drug release, we could conclude that both amorphisation and spheronization were equally successful in promoting in vitro dissolution enhancement as well as providing a more rapid onset time for drug action in vivo.

A top-down technique to improve the solubility and bioavailability of aceclofenac: in vitro and in vivo studies

The aim of the present work was to tackle the solubility issue of a biopharmaceutics classification system (BCS)-II drug, aceclofenac. Although a number of attempts to increase the aqueous solubility have been made, none of the methods were taken up for scale-up. Hence size reduction technique by a top-down approach using wet milling process was utilized to improve the solubility and, consequently, the dissolution velocity of aceclofenac. The quality of the final product was ensured by Quality by Design approach wherein the effects of critical material attributes and critical process parameters were assessed on the critical quality attributes (CQAs) of nanocrystals. Box–Behnken design was applied to evaluate these effects on critical quality attributes. The optimized nanocrystals had a particle size of 484.7±54.12 nm with a polydispersity index (PDI) of 0.108±0.009. The solid state characterization of the formulation revealed that the crystalline nature of the drug was slightly reduced after the milling process. With the reduced particle size, the solubility of the nanocrystals was found to increase in both water and 0.1 N HCl when compared with that of unmilled pure aceclofenac. These results were further supported by in vitro release studies of nanocrystals where an appreciable dissolution velocity with 100.07%±2.38% release was observed for aceclofenac nanocrystals compared with 47.66%±4.53% release for pure unmilled aceclofenac at the end of 2 h. The in vivo pharmacokinetic data generated showed a statistically significant increase in the C_max for aceclofenac nanocrystals of 3.75±0.28 µg/mL (for pure unmilled aceclofenac C_max was 1.96±0.17 µg/mL). The results obtained indicated that the developed nanocrystals of aceclofenac were successful in improving the solubility, thus the absorption and bioavailability of the drug. Hence, it may be a viable and cost-effective alternative to the current therapy.

Preparation and In Vivo Pharmacokinetics of the Tongshu Suppository

Astragalus polysaccharide (APS) (used for intestinal protection) was added to formulate the Tongshu suppository to improve the pharmacokinetics of Aceclofenac, which were assessed in New Zealand rabbits using an orthogonal experimental design. The single-agent Aceclofenac was taken as the control formulation. The concentration-time and drug release curves were drawn, and T max (min), C max (μg·mL(-1)), AUC0→∞ , and MRT were compared using a pharmacokinetic systems program. The formulated Tongshu suppository had moderate hardness, a smooth surface with uniform color, and theoretical drug-loading rate of 8%. Its release rate was in accordance with the drug preparation requirements. The concentration-time curves and drug release curves revealed that the maximum concentrations (C max) were 4.18 ± 1.03 μg·mL(-1) and 3.34 ± 0.41 μg·mL(-1) for the Tongshu and Aceclofenac suppositories, respectively, showing statistically insignificant difference, while the peak times were 34.87 ± 4.69 min and 34.76 ± 6.34 min, respectively, also showing statistically insignificant difference. Compared with the Aceclofenac suppository, the relative bioavailability of the Tongshu suppository was 104.4%, and the difference between them was statistically insignificant. In this experiment, the Tongshu suppository was prepared using the hot-melt method. In vivo pharmacokinetic studies confirmed it had higher bioavailability than the Aceclofenac suppository.

Spherical crystallization: A technique use to reform solubility and flow property of active pharmaceutical ingredients

Tablets have been choice of manufacturers over the years due to their comparatively low cost of manufacturing, packaging, shipping, and ease of administration; also have better stability and can be considered virtually tamper proof. A major challenge in formulation development of the tablets extends from lower solubility of the active agent to the elaborated manufacturing procedures for obtaining a compressible granular material. Moreover, the validation and documentation increases, as the numbers of steps increases for an industrially acceptable granulation process. Spherical crystallization (SC) is a promising technique, which encompass the crystallization, agglomeration, and spheronization phenomenon in a single step. Initially, two methods, spherical agglomeration, and emulsion solvent diffusion, were suggested to get a desired result. Later on, the introduction of modified methods such as crystallo-co-agglomeration, ammonia diffusion system, and neutralization techniques overcame the limitations of the older techniques. Under controlled conditions such as solvent composition, mixing rate and temperature, spherical dense agglomerates cluster from particles. Application of the SC technique includes production of compacted spherical particles of drug having improved uniformity in shape and size of particles, good bulk density, better flow properties as well as better solubility so SC when used on commercial scale will bring down the production costs of pharmaceutical tablet and will increase revenue for the pharmaceutical industries in the competitive market. This review summarizes the technologies available for SC and also suggests the parameters for evaluation of a viable product.

Preparation of spherical agglomerates from potash alum

Spherical crystallization proved to be feasible for the preparation of spherical salt hydrate particles as core material for microencapsulation.

Formulation Development of Spherical Crystal Agglomerates of Itraconazole for Preparation of Directly Compressible Tablets with Enhanced Bioavailability

The objective of the present work was to formulate tablet dosage form of itraconazole with enhanced bioavailability. Spherical crystal agglomerates (SCA) of itraconazole prepared by quasi emulsification solvent diffusion method using Soluplus and polyethylene glycol 4000 (PEG 4000) showed increased solubility (540 μg/ml) in 0.1 N hydrochloric acid as compared to pure drug (12 μg/ml). A Fourier transform infrared (FTIR) study indicated compatibility of drug with the excipients. The developed SCA were spherical with smooth surface having an average size of 412 μm. The significantly improved micromeritic properties compared to the plain drug suggested its suitability for direct compression. The antifungal activity of itraconazole was retained in the SCA form as evidenced from the results of the disc diffusion method. The optimized SCA formulation could be easily compressed into tablet with desirable characteristics of hardness (5 kg/cm(2)) and disintegration time (6.3 min). The in vitro dissolution studies showed significant difference in the dissolution profiles of pure drug (21%) and SCA formulation (85%) which was even greater than that of marketed preparation (75%). In vivo pharmacokinetic showed significant enhancement in C max and AUC0-t with relative bioavailability of 225%. The SCA formulation seems to be promising for enhancement of oral bioavailability of itraconazole.

Chitosan cocrystals embedded alginate beads for enhancing the solubility and bioavailability of aceclofenac

Enhanced oral bioavailability of aceclofenac has been achieved using chitosan cocrystals of aceclofenac and its entrapment into alginate matrix a super saturated drug delivery system (SDDS). Prepared SDDS were evaluated by various physiochemical and pharmacological methods. The result revealed that the primary cocrystals enhanced the solubility of the drug and the thick gelled polymer matrix that formed from swelling of calcium alginate beads makes it to release the drug in continuous and sustained manner by supersaturated drug diffusion. The Cmax, Tmax and relative bioavailability for aceclofenac cocrystal and aceclofenac SDDS were 2.06±0.42 μg/ml, 1 h, 159.72±10.84 and 2.01 μg/ml, 1 h, 352.76±12.91, respectively. Anti-inflammatory activity of aceclofenac was significantly improved with the SDDS. With respect to the results, it revealed that the SDDS described herein might be a promising tool for the oral sustained release of aceclofenac and likely for that of various other poorly soluble drugs.

Preparation and evaluation of agglomerated crystals by crystallo-co-agglomeration: an integrated approach of principal component analysis and Box-Behnken experimental design

Poor mechanical properties of crystalline drug particles require wet granulation technique for tablet production which is uneconomical, laborious, and tedious. The present investigation was aimed to improve flow and mechanical properties of racecadotril (RCD), a poorly water soluble antidiarrheal agent, by a crystallo-co-agglomeration (CCA) technique. The influence of various excipients and processing conditions on formation of directly compressible agglomerates of RCD was evaluated. Principal component analysis and Box-Behnken experimental design was implemented to optimize the agglomerates with good micromeritics and mechanical properties. The overall yield of the process was 88-98% with size of agglomerates between 351 and 1214 μm. Further, higher rotational speed reduced the size of agglomerates and disturbed sphericity. The optimized batch of agglomerates exhibited excellent flowability and crushing strength. The optimized batch of RCD agglomerates was characterized by fourier transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffractometry and gas chromatography which illustrated absence of drug-excipient interaction with minimal entrapment of residual solvent. Hence, it may be concluded that both excipients and processing conditions played a vital role to prepare spherical crystal agglomerates of RCD by CCA and it can be adopted as an excellent alternative to wet granulation.

Influence of excipients and processing conditions on the development of agglomerates of racecadotril by crystallo-co-agglomeration

Purpose:

The purpose of the present investigation was to improve the flow and mechanical properties of racecadotril by a crystallo-co-agglomeration (CCA) technique. Direct tableting is a requirement of pharmaceutical industries. Poor mechanical properties of crystalline drug particles require wet granulation which is uneconomical, laborious, and tedious.

Materials and Methods:

The objective of this work was to study the influence of various polymers/excipients and processing conditions on the formation of directly compressible agglomerates of the water-insoluble drug, racecadotril, an antidiarrheal agent. The agglomerates of racecadotril were prepared using dichloromethane (DCM)–water as the crystallization system. DCM acted as a good solvent for racecadotril as well as a bridging liquid for the agglomeration of the crystallized drug and water as the nonsolvent. The prepared agglomerates were tested for micromeritic and mechanical properties.

Results:

The process yielded ~90 to 96% wt/ wt spherical agglomerates containing racecadotril with the diameter between 299 and 521 μ. A higher rotational speed of crystallization system reduces the size of the agglomerates and disturbs the sphericity. Spherical agglomerates were generated with a uniform dispersion of the crystallized drug. CCA showed excellent flowability and crushing strength.

Conclusion:

Excipients and processing conditions can play a key role in preparing spherical agglomerates of racecadotril by CCA, an excellent alternative to the wet granulation process to prepare intermediates for direct compression.

Spherical crystallization of drugs

Spherical crystallization of drugs is the process of obtaining larger particles by agglomeration during crystallization. The most common techniques used to obtain such particles are spherical agglomeration and quasi-emulsion solvent diffusion. Ammonia diffusion systems and crystallo-co-agglomeration are extensions of these techniques. By controlling process parameters during crystallization, such as temperature, stirring rate, type and amount of solvents, or excipient selection, it is possible to control the formation of agglomerates and obtain spherical particles of the desired size, porosity, or hardness. Researchers have reported that the particles produced have improved micromeritic, physical, and mechanical properties, which make them suitable for direct compression. In some cases, when additional excipients are incorporated during spherical crystallization, biopharmaceutical parameters including the bioavailability of drugs can also be tailored.

Sustained release spherical agglomerates of polymethacrylates containing mefenamic acid: in vitro release, micromeritic properties and histological studies

Mefenamic acid (MA) spherical agglomerates (SAs) were prepared with various polymethacrylates having different permeability characteristics (Eudragit RS 100, Eudragit RL 100 and Eudragit L 100) and also with combination of Eudragit RS 100 and Eudragit L 100 in different ratios. SAs were prepared by spherical crystallization method using ethanol/dichloromethane solvent (crystallization) system. The influence of various formulation factors on the encapsulation efficiency, as in vitro drug release, and micromeritic properties was investigated. Target release profile of MA was also drawn. The yields of preparation and the encapsulation efficiencies were high for all formulations. The shape and surface characteristics of SAs were observed by a scanning electron microscope. The particle sizes are in the range of 0.219 ± 0.1 to 0.482 ± 0.25 mm (mean ± confidence interval t(95%)). In addition, histological studies showed that the administration of MA in SAs containing Eudragit RS/L provided a distinct tissue protection in the stomach and duodenum. Differential scanning calorimetry and X-ray diffraction of powder studies showed that MA particles crystallized in the presence of polymethacrylates did not undergo structural modifications.

Preparation and characterization of co-grinded mixtures of aceclofenac and neusilin US2 for dissolution enhancement of aceclofenac

The present study was carried out with a view to enhance the dissolution of poorly water-soluble BCS-class II drug aceclofenac by co-grinding with novel porous carrier Neusilin US(2.) (amorphous microporous granules of magnesium aluminosilicate, Fuji Chemical Industry, Toyama, Japan). Neusilin US(2) has been used as an important pharmaceutical excipient for solubility enhancement. Co-grinding of aceclofenac with Neusilin US(2) in a ratio of 1:5 was carried out by ball milling for 20 h. Samples of co-ground mixtures were withdrawn at the end of every 5 h. and characterized for X-ray powder diffraction, differential scanning calorimetry, and Fourier-transform infrared spectroscopy. The analysis revealed the conversion of crystalline aceclofenac to its amorphous form upon milling with Neusilin US(2). Further, in vitro dissolution rate of aceclofenac from co-ground mixture was significantly higher compared to pure aceclofenac. The accelerated stability study of co-ground mixture was carried out at 40 degrees C/75%RH for 4 weeks, and it showed that there was no reversion from amorphous to crystalline form. Thus, it is advantageous to use a porous carrier like Neusilin US(2) in improvement of dissolution of poorly soluble drugs.