Development and evaluation of orally disintegrating tablets of cilostazol-β-cyclodextrin inclusion complexes

Context: The clinical applications of cilostazol (CLZ) are limited by its low aqueous solubility (<5?µg/ml) and high biovariability.

Objective: The aim of this study was to enhance the solubility of CLZ by forming inclusion complexes (ICs) with beta cyclodextrin (β-CD) and formulating them into oral disintegrating tablets.

Methods: Phase solubility study of CLZ with β-CD was performed in water. Job’s plot was constructed to determine the stoichiometry of ICs. ICs, prepared by spray-drying technique, were characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, hot stage microscopy, powder X-ray diffraction and nuclear magnetic resonance. Molecular modeling studies were performed to understand the mode of interaction of CLZ with β-CD. The formulation process was undertaken using a reproducible design of experiment generated model, attained by variation of diluents and disintegrants at three levels. Tablets were evaluated for drug content, hardness, friability, disintegration time (DT), wetting time (WT) and dissolution profiles.

Results and discussion: Phase solubility studies suggested an A_L type curve with stability constant (K_s) of 922.52?M^?1. Job’s plot revealed 1:2 stoichiometry. All analytical techniques confirmed inclusion complexation. Molecular modeling revealed dispersive van der Waals interaction energy as a major contributor for stabilization of complex. The spray-dried complexes showed higher solubility and faster dissolution compared to plain CLZ. The optimized formulation showed DT of 11.1?±?0.8?s, WT of 8.7?±?0.9?s and almost complete dissolution of CLZ in 15?min.

Conclusion: The prepared tablets with low DT and fast dissolution will prove to be a promising drug delivery system with improved bioavailability and better patient compliance.     

Inclusion complexes of bendamustine with β-CD,HP-β-CD and Epi-β-CD: in-vitro and in-vivo evaluation

Abstract

The objective of the present work was to investigate the inclusion behavior of bendamustine (BM) with β-cyclodextrin and its hydrophilic derivatives (HP-β-CD and Epi-β-CD) for the enhancement of aqueous solubility, dissolution and bioavailability. The supramolecular binary complexes were prepared by three different methods, viz. physical mixture (PM), kneading (KND) and co-evaporation (COE). Phase-solubility study revealed the higher solubilizing and complexing ability of polymerized cyclodextrin (K_s?=?645?M^?1) than parent cyclodextrin (K_s?=?43?M^?1) and chemically derived cyclodextrin (K_s?=?100?M^?1). Meanwhile, the solubility of BM was significantly enhanced in phosphate buffer of pH 6.8, which was 24.5 folds greater compared with the phosphate buffer pH 4.5 and four times greater than aqueous medium. The dissolution efficiency was found to be highest for BM: Epi-β-CD complex (87%) compared to BM: HP-β-CD complex (84%), BM: β-CD (79%) and pure drug (20%). In-vivo pharmacokinetic study revealed that the bioavailability of BM was enhanced 2.55 times on complexation with Epi-β-CD using KND method. The t_1/2 of BM was increased from 34.2?min to approximately 75.7?min, allowing the absorption for longer time. The order of increase in solubility, dissolution and bioavailability of BM was KND?>?COE?>?PM?>?pure drug. Thus, the strategy of host–guest inclusion was very effective and could be successfully used in the development of suitable pharmaceutical dosage form with enhanced therapeutic activity.     

Enhancement of oral bioavailability of anti-HIV drug rilpivirine HCl through nanosponge formulation*

Objective: To synthesize β cyclodextrin nanosponges using a novel and efficient microwave mediated method for enhancing bioavailability of Rilpivirine HCl (RLP).

Significance: Belonging to BCS class II RLP has pH dependent solubility and poor oral bioavailability. However, a fatty meal enhances its absorption hence the therapy indicates that the dosage form be consumed with a meal. But then it becomes tedious and inconvenient to continue the therapy for years with having to face the associated gastric side effects such as nausea.

Method: Microwave synthesizer was used to mediate the poly-condensation reaction between β-cyclodextrin and cross-linker diphenylcarbonate. Critical parameters selected were polymer to cross-linker ratio, Watt power, reaction time and solvent volume. Characterization studies were performed using FTIR, DSC, SEM, ¹H-NMR and PXRD. Molecular modeling was applied to confirm the possibility of drug entrapment. In vitro drug dissolution followed by oral bioavailability studies was performed in Sprawley rats. Samples were analyzed using HPLC.

Results: Microwave synthesis yields para-crystalline, porous nanosponges (～205?nm). Drug entrapment led to enhancement of solubility and a two-fold increase in drug dissolution (P?C_max and AUC_0-∞ increases significantly (C_max of NS～ 586?±?5.91?ng/mL; plain RLP ～310?±?5. 74?ng/mL).

Conclusion: The approach offers a comfortable dosing zone for AIDs patients, negating the requirement of consuming the formulation in a fed state due to enhancement in drugs’ oral bioavailability.     

Nanosuspension of efavirenz for improved oral bioavailability: formulation optimization,in vitro,in situ and in vivo evaluation

Context: Nanosuspensions (NSs) of poorly water-soluble drugs are known to increase the oral bioavailability.

Objectives: The purpose of this study was to develop NS of efavirenz (EFV) and to investigate its potential in enhancing the oral bioavailability of EFV.

Materials and methods: EFV NS was prepared using the media milling technique. The Box–Behnken design was used for optimization of the factors affecting EFV NS. Sodium lauryl sulfate and PVP K30 were used to stabilize the NS. Freeze-dried NS was completely re-dispersed with double-distilled filtered water.

Results: Mean particle size and zeta potential of the optimized NS were found to be 320.4?±?3.62?nm and –32.8?±?0.4 mV, respectively. X-ray diffraction and differential scanning calorimetric analysis indicated no phase transitions. Rate and extent of drug dissolution in the dissolution medium for NS was significantly higher compared to marketed formulation. The parallel artificial membrane permeability assay revealed that NS successfully enhanced the permeation of EFV. Results of in situ absorption studies showed a significant difference in absorption parameters such as K_a, t_1/2 and uptake percentages between lyophilized NS and marketed formulation of EFV. Oral bioavailability of EFV in rabbits resulting from NS was increased by 2.19-fold compared to the marketed formulation.

Conclusion: Thus, it can be concluded that NS formulation of EFV can provide improved oral bioavailability due to enhanced solubility, dissolution velocity, permeability and hence absorption.     

Preparation,characterization and in vitro and in vivo evaluation of a solid dispersion of Naringin

Naringin (NA) is one of typical flavanone glycosides widely distributed in nature and possesses several biological activities including antioxidant, anti-inflammatory, and antiapoptotic. The aim of this study was to develop solid dispersion (SD) and to improve the dissolution rate and oral bioavailability of NA. NA–SD was prepared by the traditional preparation methods using PEG6000, F68, or PVP K30 as carrier at different drug to carrier ratios. According to the results of solubility and in vitro dissolution test, the NA–PEG6000 (1:3) SD was considered as an optimal formulation to characterize by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry and powder X-ray diffraction. Furthermore, oral bioavailabilities of NA–PEG6000 (1:3) SD and NA–suspension with the same dosage were investigated in SD rats. The results confirmed the formation of SD and the pharmacokinetic parameters of NA–PEG6000 (1:3) SD (C_max?=?0.645?±?0.262?µg/ml, AUC_0–t?=?0.471?±?0.084?µg/ml?h) were higher than that of NA–suspension (C_max?=?0.328?±?0.183?µg/ml, AUC_0–t =?0.361?±?0.093?µg/ml?h). Based on the results, the SD is considered as a promising approach to enhance the dissolution rate and oral bioavailability of NA.     

Lipid nanoparticles of zaleplon for improved oral delivery by Box–Behnken design: optimization,in vitro and in vivo evaluation

Purpose: Zaleplon (ZL) is a hypnotic drug prescribed for the management of insomnia and convulsions. The oral bioavailability of ZL was low (～30%) owing to poor water solubility and hepatic first-pass metabolism. The cornerstone of this investigation is to develop and optimize solid lipid nanoparticles (SLNs) of ZL with the aid of Box–Behnken design (BBD) to improve the oral bioavailability.

Methods: A design space with three formulation variables at three levels were evaluated in BBD. Amount of lipid (A₁), amount of surfactant (A₂) and concentration of co-surfactant (%) (A₃) were selected as independent variables, whereas, particle size (B₁), entrapment efficiency (B₂) and zeta potential (ZP, B₃) as responses. ZL-SLNs were prepared by hot homogenization with ultrasonication method and evaluated for responses to obtain optimized formulation. Morphology of nanoparticles was observed under SEM. DSC and XRD studies were examined to understand the native crystalline behavior of drug in SLN formulations. Further, in vivo studies were performed in Wistar rats.

Results: The optimized formulation with 132.89?mg of lipid, 106.7?mg of surfactant and 0.2% w/v of co-surfactant ensued in the nanoparticles with 219.9?±?3.7?nm of size, ?25.66?±?2.83?mV surface charge and 86.83?±?2.65% of entrapment efficiency. SEM studies confirmed the spherical shape of SLN formulations. The DSC and XRD studies revealed the transformation of crystalline drug to amorphous form in SLN formulation. In conclusion, in vivo studies in male Wistar rats demonstrated an improvement in the oral bioavailability of ZL from SLN over control ZL suspension.

Conclusions: The enhancement in the oral bioavailability of ZL from SLNs, developed with the aid of BBD, explicated the potential of lipid-based nanoparticles as a potential carrier in improving the oral delivery of this poorly soluble drug.     

Mechanism of enhanced oral absorption of akebia saponin D by a self-nanoemulsifying drug delivery system loaded with phospholipid complex

Akebia saponin D (ASD) exhibits a variety of pharmacological activities, such as anti-osteoporosis, neuroprotection, hepatoprotection, but has poor oral bioavailability. A self-nanoemulsifying drug delivery system loaded with akebia saponin D - phospholipid complex (APC-SNEDDS) (composition: Peceol: Cremophor^® EL: Transcutol HP: ASD: phospholipid; ratio: 10:45:45:51:12.3, w:w:w:w:w) was first developed to improve the oral absorption of saponins and it was found to significantly enhance ASD’s oral bioavailability by 4.3 - fold (p?<?.01). This study was conducted to elucidate the mechanism of enhanced oral absorption of ASD by the drug delivery system of APC-SNEDDS. The aggregation morphology and particle size of ASD and APC-SNEDDS prepared in aqueous solutions were determined by transmission electron microscope and particle size analyzer, respectively. Stability of ASD and APC-SNEDDS in gastrointestinal luminal contents and mucosa homogenates were also explored. The differences of in situ intestinal permeability of ASD and APC-SNEDDS were compared. APC-SNEDDS reduced the aggregation size from 389?±?7?nm (ASD) to 148?±?3?nm (APC-SNEDDS). APC-SNEDDS increased the remaining drug in large intestine luminal contents from 47?±?1% (ASD) to 83?±?1% (APC-SNEDDS) during 4?h incubation. APC-SNEDDS provided an 11-fold increase in Ka value and an 11-fold increase in P_eff value compared to ASD. In summary, APC-SNEDDS improved ASD’s oral bioavailability mainly by increasing membrane permeability, destroying self-micelles and inhibiting the intestinal metabolism.     

Development and evaluation of nanosized niosomal dispersion for oral delivery of Ganciclovir

Encapsulation of Ganciclovir in lipophilic vesicular structure may be expected to enhance the oral absorption and prolong the existence of the drug in the systemic circulation. So the purpose of the present study was to improve the oral bioavailability of Ganciclovir by preparing nanosized niosomal dispersion. Niosomes were prepared from Span40, Span60, and Cholesterol in the molar ratio of 1:1, 2:1, 3:1, and 3:2 using reverse evaporation method. The developed niosomal dispersions were characterized for entrapment efficiency, size, shape, in vitro drug release, release kinetic study, and in vivo performance. Optimized formulation (NG8; Span60:Cholesterol 3:2 molar ratio) has shown a significantly high encapsulation of Ganciclovir (89?±?2.13%) with vesicle size of 144?±?3.47?nm (polydispersity index [PDI]?=?0.08). The in vitro release study signifies sustained release profile of niosomal dispersions. Release profile of prepared formulations have shown that more than 85.2?±?0.015% drug was released in 24?h with zero-order release kinetics. The results obtained also revealed that the types of surfactant and Cholesterol content ratio altered the entrapment efficiency, size, and drug release rate from niosomes. In vivo study on rats reveals five-time increment in bioavailability of Ganciclovir after oral administration of optimized formulation (NG8) as compared with tablet. The effective drug concentration (>0.69 µg/mL in plasma) was also maintained for at least 8?h on administration of the niosomal formulation. In conclusion, niosomes can be proposed as a potential oral delivery system for the effective delivery of Ganciclovir.     

Fabrication of solid lipid nanoparticles of lurasidone HCl for oral delivery: optimization,in vitro characterization,cell line studies and in vivo efficacy in schizophrenia

Objective: The aim of the present investigation was to investigate the efficacy of solid lipid nanoparticles (SLNs) to enhance the absorption and bioavailability of lurasidone hydrochloride (LH) following oral administration.

Methods: The LH loaded SLNs (LH-SLNs) were prepared by high pressure homogenization (HPH) method, optimized using box Behnken design and evaluated for particle size (PS), entrapment efficiency (EE), morphology, FTIR, DSC, XRD, in vitro release, ex vivo permeation, transport studies across Caco-2 cell line and in vivo pharmacokinetic and pharmacodynamic studies.

Results: The LH-SLNs had PS of 139.8?±?5.5?nm, EE of 79.10?±?2.50% and zeta potential of ?30.8?±?3.5?mV. TEM images showed that LH-SLNs had a uniform size distribution and spherical shape. The in vitro release from LH-SLNs followed the Higuchi model. The ex vivo permeability study demonstrated enhanced drug permeation from LH-SLNs (>90%) through rat intestine as compared to LH-suspension. The SLNs were found to be taken up by energy dependent, endocytic mechanism which was mediated by clathrin/caveolae-mediated endocytosis across Caco-2 cell line. The pharmacokinetic results showed that oral bioavailability of LH was improved over 5.16-fold after incorporation into SLNs as compared to LH-suspension. The pharmacodynamic study proved the antipsychotic potential of LH-SLNs in the treatment of schizophrenia.

Conclusion: It was concluded that oral administration of LH-SLNs in rats improved the bioavailability of LH via lymphatic uptake along with improved therapeutic effect in MK-801 induced schizophrenia model in rats.     

Preparation,characterization, and pharmacokinetics study of a novel genistein-loaded mixed micelles system

Genistein (GEN), is a natural dietary isoflavone, has been reported to show anticancer activities. However, its poor aqueous solubility and oral bioavailability limit its clinical application. We designed a novel genistein-loaded mixed micelles (GEN-M) system composed of Soluplus^® and Vitamin E d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were prepared by organic solvent evaporation aimed to overcome the challenges of GEN’s poor solubility and then further improve its oral bioavailability. The optimized, spherical-shaped GEN-M was obtained at a ratio of 10:1 (Soluplus^®:TPGS). The mean particle size of GEN-M was 184.7?±?2.8?nm, with a narrow polydispersity index (PDI) of 0.162?±?0.002. The zeta potential value of GEN-M was ?2.92?±?0.01?mV. The micelles solutions was transparent with blue opalescence has high the entrapment efficiency (EE) and drug loading (DL) of 97.12?±?2.11 and 3.87?±?1.26%, respectively. GEN-M was demonstrated a sustained release behavior when formed micelles shown in drug release in vitro. The solubility of GEN in water increased to 1.53?±?0.04?mg/mL after encapsulation. The permeability of GEN across a Caco-2 cell monolayer was enhanced, and the pharmacokinetics study of GEN-M showed a 2.42-fold increase in relative oral bioavailability compared with free GEN. Based on these findings, we conclude that this novel nanomicelles drug delivery system could be leveraged to deliver GEN and other hydrophobic drugs.     

Improved oral bioavailability of valsartan using proliposomes: design,characterization and in vivo pharmacokinetics

Abstract

The objective of our investigational work was to develop a proliposomal formulation to improve the oral bioavailability of valsartan. Proliposomes were formulated by thin film hydration technique using different ratios of phospholipids:drug:cholesterol. The prepared proliposomes were evaluated for vesicle size, encapsulation efficiency, morphological properties, in vitro drug release, in vitro permeability and in vivo pharmacokinetics. In vitro drug-release studies were performed in simulated gastric fluid (pH 1.2) and purified water using dialysis bag method. In vitro drug permeation was studied using parallel artificial membrane permeation assay (PAMPA), Caco-2 monolayer and everted rat intestinal perfusion techniques. In vivo pharmacokinetic studies were conducted in male Sprague Dawley (SD) rats. Among the proliposomal formulations, F-V was found to have the highest encapsulation efficiency of 95.6?±?2.9% with a vesicle size of 364.1?±?14.9?nm. The in vitro dissolution studies indicated an improved drug release from proliposomal formulation, F-V in comparison to pure drug suspension in both, purified water and pH 1.2 dissolution media after 12?h. Permeability across PAMPA, Caco-2 cell and everted rat intestinal perfusion studies were higher with F-V formulation as compared to pure drug. Following single oral administration of F-V formulation, a relative bioavailability of 202.36% was achieved as compared to pure valsartan.     

Design,characterization, and evaluation of intranasal delivery of ropinirole-loaded mucoadhesive nanoparticles for brain targeting

Context: Parkinson disease (PD) is a common, progressive neurodegenerative disorder, characterized by marked depletion of striatal dopamine and degeneration of dopaminergic neurons in the substantia nigra.

Objective: The purpose of the present study was to investigate the possibility of targeting an anti-Parkinson’s drug ropinirole (RH) to the brain using polymeric nanoparticles.

Materials and methods: Ropinirole hydrochloride (RH)-loaded chitosan nanoparticles (CSNPs) were prepared by an ionic gelation method. The RH-CSNPs were characterized for particle size, polydispersity index (PDI), zeta potential, loading capacity, entrapment efficiency in vitro release study, and in vivo distribution after intranasal administration.

Results and discussion: The RH-CSNPs showed sustained release profiles for up to 18?h. The RH concentrations (% Radioactivity/g) in the brain following intranasal administration (i.n.) of RH-CSNPs were found to be significantly higher at all the time points compared with RH solution. The concentration of RH was highest in the liver (7.210?±?0.52), followed by kidneys (6.862?±?0.62), intestine (4.862?±?0.45), and lungs (4.640?±?0.92) in rats following i.n. administration of RH-CSNPs. Gamma scintigraphy imaging in rats was performed to ascertain the localization of drug in the brain following intranasal administration of formulations. The brain/blood ratios obtained (0.251?±?0.09 and 0.386?±?0.57 of RH (i.n.) and RH-CSNPs (i.n.), respectively) at 0.5?h are indicative of direct nose to brain transport, bypassing the blood–brain barrier (BBB).

Conclusion: The novel formulation showed the superiority of nose to brain delivery of RH using mucoadhesive nanoparticles compared with other delivery routes reported earlier.     

Harmine-loaded galactosylated pluronic F68-gelucire 44/14 mixed micelles for liver targeting

Harmine (HM), a phytoconstituent has wide range of pharmacological activities including antimicrobial, antifungal, antioxidative, and anticancer. HM has shown promising anticancer activity against liver cancer cells. However, poor aqueous solubility, multidrug pump P-gp efflux, extensive in vivo metabolism, and rapid elimination due to glucuronidation/sulfation limit clinical utility of HM. In order to overcome the drawbacks of HM, the current work reports preparation of HM-loaded galactosylated pluronic F-68 (PF68)-Gelucire^® 44/14 (GL44) mixed micelles (HM-MM). 3² factorial design was used to investigate the effect of formulation variables on formation HM-loaded mixed micelles. Solvent evaporation method was used for preparation of HM-MM. The optimized HM-MM was evaluated for size, percent drug entrapped (EE), in vitro HM release, oral bioavailability, and biodistribution in rats. HM-MM with an average size 277.5?±?3.24?nm had an EE of 86.5?±?1.51% w/w. HM-MM released HM in a controlled manner. Additionally, HM-MM showed significant enhancement in oral bioavailability (around six-folds) of HM when compared to HM alone. Further, HM-MM showed around sevenfold higher amount of HM in the liver when compared to HM alone revealing efficient drug targeting capability. Such significant improvement in oral bioavailability of HM when formulated into mixed micelles could be attributed to solubilization of hydrophobic HM into micellar core along with P-gp inhibition effect of both galactosylated PF68 and GL44. Thus, the present work highlights galactosylated PF68 and GL44 mixed micelles as an efficient carrier system having drug targeting capability and potential to enhance bioavailability of BCS class II drugs.     

Pharmacokinetic and pharmacodynamic studies of nisoldipine-loaded solid lipid nanoparticles developed by central composite design

Abstract

Objective: Nisoldipine (ND) is a potential antihypertensive drug with low oral bioavailability. The aim was to develop an optimal formulation of ND-loaded solid lipid nanoparticles (ND-SLNs) for improved oral bioavailability and pharmacodynamic effect by using a two-factor, three-level central composite design. Glyceryl trimyristate (Dynasan 114) and egg lecithin were selected as independent variables. Particle size (Y₁), PDI (Y₂) and entrapment efficiency (EE) (Y₃) of SLNs were selected as dependent response variables.

Methods: The ND-SLNs were prepared by hot homogenization followed by ultrasonication. The size, PDI, zeta potential, EE, assay, in vitro release and morphology of ND-SLNs were characterized. Further, the pharmacokinetic (PK) and pharmacodynamic behavior of ND-SLNs was evaluated in male Wistar rats.

Results: The optimal ND-SLN formulation had particle size of 104.4?±?2.13?nm, PDI of 0.241?±?0.02 and EE of 89.84?±?0.52%. The differential scanning calorimetry and X-ray diffraction analyses indicated that the drug incorporated into ND-SLNs was in amorphous form. The morphology of ND-SLNs was found to be nearly spherical by scanning electron microscopy. The optimized formulation was stable at refrigerated and room temperature for 3 months. PK studies showed that 2.17-fold increase in oral bioavailability when compared with a drug suspension. In pharmacodynamic studies, a significant reduction in the systolic blood pressure was observed, which sustained for a period of 36?h when compared with a controlled suspension.

Conclusion: Taken together, the results conclusively demonstrated that the developed optimal ND-SLNs caused significant enhancement in oral bioavailability along with pharmacodynamic effect.     

Sigma-2 receptor ligand anchored telmisartan loaded nanostructured lipid particles augmented drug delivery,cytotoxicity, apoptosis and cellular uptake in prostate cancer cells

Recently, the anticancer activity of telmisartan (TEL) has been discovered against prostate cancer. Nevertheless, despite favorable therapeutic profile, poor aqueous solubility and suboptimal oral bioavailability hamper the anticancer efficacy of TEL. Therefore, in this investigation, sigma-2 receptor ligand, 3-(4-cyclohexylpiperazine-1-yl) propyl amine (CPPA) anchored nanostructured lipid particles of telmisartan (CPPA-TEL-NLPs) were engineered using stearic acid for targeting prostate cancer, PC-3 cells. The mean particle size of TEL-NLPs was measured to be 25.4?±?3.2?nm, significantly (p?p?p?In vitro drug release study was conducted to determine the drug delivery potential of tailored nanoparticles. TEL-NLPs released 93.36% of drug significantly (p?50 of CPPA-TEL-NLPs was measured to be 20.3?µM significantly (p?50 of 41.3?µM, significantly (p?>?0.05) not different from 43.4?µM, exhibited by TEL-NLPs in PNT-2 cells. We elucidated that CPPA-TEL-NLPs entered the PC-3 cells via receptor mediated endocytosis pathway and thus exhibited superior cytotoxicity, apoptosis and greater extent of cellular uptake in PC-3 cells. In conclusion, CPPA-TEL-NLPs may be a promising nanomedicine and warrant further in vivo investigations for gaining clinical success.     

Creatinine-based non-phospholipid vesicular carrier for improved oral bioavailability of Azithromycin

Context: Novel, safe, efficient and cost effective nano-carriers from renewable resources have got greater interest for enhancing solubility and bioavailability of hydrophobic dugs.

Objectives: This study reports the synthesis of a novel biocompatible non-phospholipid human metabolite "Creatinine" based niosomal delivery system for Azithromycin improved oral bioavailability.

Methods: Synthesized surfactant was characterized through spectroscopic and spectrometric techniques and then the potential for niosomal vesicle formation was evaluated using Azithromycin as model drug. Drug loaded vesicles were characterized for size, polydispersity index (PDI), shape, drug encapsulation efficiency (EE), in vitro release and drug–excipient interaction using zetasizer, atomic force microscope (AFM), LC–MS/MS and FTIR. The biocompatibility of surfactant was investigated through cells cytotoxicity, blood hemolysis and acute toxicity. Azithromycin encapsulated in niosomes was investigated for in vivo bioavailability in rabbits.

Results: The vesicles were spherical with 247?±?4.67?nm diameter hosting 73.29?±?3.51% of the drug. Surfactant was nontoxic against cell cultures and caused 5.80?±?0.51% hemolysis at 1000?µg/mL. It was also found safe in mice up to 2.5?g/kg body weight. Synthesized surfactant based niosomal vesicles revealed enhanced oral bioavailability of Azithromycin in rabbits.

Conclusions: The results of the present study confirm that the novel surfactant is highly biocompatible and the niosomal vesicles can be efficiently used for improving the oral bioavailability of poor water soluble drugs.     

An optimized commercially feasible milling technique for molecular encapsulation of meloxicam in β-cyclodextrin

Background: The practical applicability of solid dispersions (SD) for improvement of oral bioavailability of poorly water-soluble drugs has still remained limited because of lack of feasibility for scale-up of manufacturing processes. The present research work deals with the preparation of SDs of meloxicam (MLX) with β-cyclodextrin (β-CD) by the ball-milling technique to overcome the scale-up issues.

Methods: Phase-solubility studies were conducted to analyze the influence of β-CD on solubility of MLX. In vitro dissolution studies on various complexes as well as tablets prepared on pilot scale in an industrial set up were performed and compared with the marketed products. Physicochemical characterization of optimized complexes was done using various methods to study drug-β-CD interaction.

Results: Solubility of pure MLX in water at 25°C was found to be only 9.4 µg/mL. The AL type of phase-solubility profile of MLX with β-CD [stability constant (K_1:1)?=?22.056?M^?1 and Gibbs free energy (ΔF^o)?=?–7.665 KJ/mole] confirmed the solubility enhancement capability of β-CD. Milling time of 6?h was considered to be optimum and showed maximum enhancement of drug dissolution. The amorphous nature of the milled complex and mode of interaction of MLX with β-CD was confirmed by differential scanning calorimetry (DSC), x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectrophotometry (¹HNMR). Tablets containing MLX-β-CD (1:1.5?M) milled complexes showed the best release (T_90%?=?10.94?min) compared to the marketed products (T_90% ≥ 450?min). Stability studies performed confirmed the integrity of the amorphous complex.

Conclusion: Stable inclusion complexes of MLX-β-CD with enhanced aqueous solubility and dissolution rate were prepared by a highly efficient and controlled large-scale milling technique.     

Anti-hyperuricemic property of 6-shogaol via self-micro emulsifying drug delivery system in model rats: formulation design,in vitro and in vivo evaluation

The prevalence of hyperuricemia is relatively high worldwide, and a great number of patients are suffering from its complications. 6-shogaol, an alkylphenol compound purified from the root of ginger (Zingiber officinale Roscoe), has been proved to possess diverse pharmacological activities. However, its poor aqueous solubility usually leads to low bioavailability, and further clinical applications will be greatly discounted. The current study aimed to formulate a 6-shogaol-loaded-Self Microemulsifying Drug Delivery System (SMEDDS) to amend low aqueous solubility and bioavailability orally, as well as, potentiate the hyperuricemic activity of the 6-shogaol. SMEDDS was developed with central composite design established on a two system components viz., 18.62% W/W ethyl oleate (oil phase) and ratio of tween 80 (surfactant) to PEG 400 (co-surfactant) (1.73:1, W/W). Based on quadratic model, the navigation of the design space could generate spherically-shaped and homogenous droplets with respective mean particle diameter, polydispersity and of 20.00?±?0.26?nm and 0.18?±?0.02. The 6-shogaol-SMEDDS showed significant elevation of cumulative release compared with the free 6-shogaol and more importantly a 571.18% increment in the relative oral bioavailability of the drug. The predominant accumulation of 6-shogaol-SMEDDS in the liver suggested hepatic-targeting potentiality of the drug. Oral administration of 6-shogaol-SMEDDS in hyperuricemic rats also significantly decreased uric acid level and xanthine oxidase activity. Histological studies confirmed formulation groups indeed could provide better protection of kidney than free drug groups. Collectively, these findings indicated that the SMEDDS hold much promise in enhancing the oral delivery and therapeutic efficacy of 6-shogaol.