Enhancement of Aqueous Solubility, Dissolution Profile, and Oral Bioavailability of Pentoxifylline by Microsponges

Microsponge, a novel drug delivery system, is designed to deliver a pharmaceutically active ingredient efficiently at the minimum dose. Microsponge plays an important role in enhancing drug stability, reducing side effects, and modifying drug release profiles. It is mostly used for transdermal delivery. Recent studies also explored their use for oral administration. This study aimed to explore the potential use of the microsponge technique in improving the aqueous solubility and dissolution profile of pentoxifylline (PTX). In this study, microsponges were prepared by a quasi-emulsion solvent diffusion method by varying concentrations of carriers. Nine different ratios of the PTX:Eudragit E-100 with varying amounts of dichloromethane were used. All formulated microsponges were evaluated for %production yield, compatibility of drug excipient, encapsulation efficiency, in vitro drug release, and in vivo bioavailability, as well as recorded by scanning electron microscopy (SEM) and differential scanning calorimetry(DSC). Our data suggested that the aqueous solubility of PTX microsponges was four times greater than that of pure drug. The in vitro drug release of selected microsponges (M8) was found to be 70%; furthermore, the in vivo study suggested that the selected formulation significantly enhanced drug concentration in the plasma (9,219 ng/mL in 12 hours) in comparison to pure drug PTX (2,476 ng/mL in 12 hours). SEM showed that the prepared microsponges were spherical with porous nature. Fourier-transform infrared spectroscopy and DSC studies confirmed an absence of incompatibility among drugs and selected excipients. The pH of the selected gel was found to be 6.8, which was compatible with those of skin and oral formulations also. All above data suggested a highly successful and beneficial use of the microsponge technique in enhancing aqueous solubility, dissolution profile, and oral bioavailability of PTX. Microsponge-based delivery of PTX may represent an alternative strategy to improve the bioavailability of the drug.

Effect of Hydrophilic Carriers for Solubility and Dissolution Enhancement of Sulfamerazine by Solid Dispersions Technique

Aims: The present research was carried out to investigate the effect of hydrophilic carriers in enhancing the solubility and dissolution rate of Sulfamerazine (SMZ) employing the fusion technique of solid dispersions (SD). Methodology: SMZ is an oral antibacterial drug exhibiting a poor dissolution profile and water solubility. SD of SMZ was prepared using poloxamer 407 (PX407) and Polyethylene glycol 6000 (PEG6000) as a hydrophilic carrier by employing the fusion technique. Results: The powder SDs were subjected for solubility, Fourier transform infrared spectrometry (FTIR), Differential scanning calorimetry (DSC), in-vitro dissolution profile, Scanning electron microscopy (SEM), and X-ray diffraction (XRD) study. The FTIR spectral analysis showed no significant incompatibility between drug and carriers and confirmed the presence of SMZ. From XRD and DSC, SMZ indicated the amorphous form in solid dispersion with larger specific surface area, resulting in a better in-vitro rate of dissolution of the drug from solid dispersions than pure drug. However, SD of PX407 (SDSMFF8) indicated higher aqueous solubility than pure SMZ. Further, SDSMFF7 showed higher in-vitro drug release 96.45±0.3% within 60 minutes, and pure drug (18.54±0.8%). Conclusion: In conclusion, enhancing thesolubility and dissolution of SMZ using hydrophilic carriers by solid dispersion technique provides new strategies for broadening its potential clinical application.

Effect of Formulation Parameter on Dissolution Rate of Flurbiprofen Using Liquisolid Compact

Attempts were made to improve solubility and the liquisolid technology dissolving of medication flurbiprofen. Liquisolid pill was developed utilizing transcutol-HP, polyethylene glycol 400, Avecil PH 102 carrier material and Aerosil 200 layer coating material. Suitable excipient amounts were determined to produce liquisolid powder using a mathematical model. On the other hand, flurbiprofen tablet with the identical composition, directly compressed, was manufactured for comparison without the addition of any unvolatile solvent. Both powder combination characterizations and after-compression tablets were evaluated. The pure drug and physical combination, and chosen liquisolid tablets were studied in order to exclude interacting with the differentional scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR). The results showed that transcutol is the ideal solvent with a solubility of 260±3.9 mg/ml in flurbiprofen. All formula developed were determined to be flowable within the specified limitations. The transcutol-like liquidsolid tablet formula of 35 percent w/w flurbiprofen and carrier to coating ratio of 10 was the most acceptable for the disintegration time, the tablet weight and other approved tablet characteristics. DSC thermographs demonstrated the development of a solid flurbiprofen amorphic solid solution for both the physical blend of the chosen liquisolid system and its tablets. The lack of chemicals interaction in medication and other components of the formula was demonstrated by the retention of all flurbiprofen characteristic peaks in all FTIR spectra. As an option to enhance solubility and dissolve flurbiprofen, which has a poor water solubility, liquisolid tablet has been evaluated.

Preparation, characterization and evaluation of fenofibrate: benzoic acid cocrystals with enhanced pharmaceutical properties

Background Cocrystallization process involved the understanding of interaction at molecular level between two molecules in context to their crystal packing and designing of new solids having improved physicochemical as well as pharmaceutical properties. In the present research, an attempt to increase the aqueous solubility and dissolution rate of a poorly aqueous soluble drug fenofibrate (FB) by formulation and evaluation of its cocrystals with benzoic acid (BZ) as a coformer was carried out. Results The drug and coformer were cocrystallized by using the solvent drop grinding method. For prediction of cocrystals formation, CSD (Cambridge Structure Database) software was utilized. Fourier transformation infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques were used for analysis of cocrystals. Albino rats were procured from institution as per IAEC guidelines for in vivo anti-hyperlipidaemic studies. The in vitro dissolution profile of cocrystals, pure drug, their physical mixture and marketed formulation was found to be 89%, 39%, 47% and 61%, respectively. Conclusions An enhanced anti-hyperlipidaemic activity of cocrystals was found compared to pure drug. The FB: BZ cocrystals also compared to the pure drug showed better dissolution profile and improved in vivo anti-hyperlipidaemic activity in rats. The study proved that cocrystals can promise to improve in vitro dissolution rate of poorly aqueous soluble drugs, which in turn can lead to better in vivo activities.

PREPARATION AND IN VIVO EVALUATION OF CANDESARTAN CILEXETIL SOLID DISPERSIONS

Objective: The present study aims at development of solid dispersions (SD) of candesartan cilexetil for enhanced solubility and bioavailability. Methods: About 18 SD formulations of candesartan cilexetil were prepared by solvent evaporation technique and evaluated. The in vitro release studies were conducted and the best formulation chosen was further characterized for Fourier transform infrared spectroscopy, Scanning electron microscope, X-ray, and stability. The in vivo evaluation study conducted in rats. Results: The formulation SD16 containing drug and Soluplus in 1:3 ratio along with 2% selective laser sintering was chosen optimal based on drug content (99.08%), and drug release (99.7%). In vivo studies conducted on SD16 showed that mean time to peak concentration (Tmax) was 2.0±0.05 and 4±0.2 h for the optimized and pure drug, respectively, while mean maximum drug concentration (Cmax) was 570.63±2.65 ng/mL and was significant as compared to the candesartan pure drug 175.146±0.07 ng/mL. Area under curve AUC0-∞ infinity for candesartan SD16 was higher (4860.61±1.05 ng.h/ml) than pure drug suspension 1480±1.72 ng.h/ml. Conclusion: Hence, the developed SD formulations enhanced the bioavailability of drug by 3 folds.

Preparation and Characterization of Nano Structured Lipid Carriers for Ocular Bacterial Infection

The problem of bacterial conjunctivitis has dramatically increased in recent years due increased pollution and modern lifestyle. The present study was focused to fabricate Sparfloxacin loaded nanostructured lipid carriers (Spar-NLCs) for ophthalmic application to improve ocular penetration of drug and give sustained release of drug to reduce dosing frequency and toxic effect of drug associated with ocular membrane. A regular two-level factorial design was used to optimize the formulation parameters that are significantly affecting the formulation attributes. Spar-NLCs with particle size 171.1 ± 11 nm, zeta potential -49 ± 6.47 mV, entrapment efficiency 89.5 ± 5% and spherical in shape was obtained. Besides this, FTIR spectroscopy, differential scanning calorimetry, and transmission electron microscopy results suggest that the drug is successfully incorporated in NLC and has excellent compatibility with the excipients. In vitro release study follows Korsmeyer peppas model and suggests that 81.35 ± 6.2% release of drug from Spar-NLCs in 12 hours. The result of ex-vivo permeation study demonstrated 349.75 ± 7.3 µg/cm2 of permeation of drug, 44.482 µg cm-2 hr -1 of flux, and 0.1482 cm hr-1 of permeability coefficient which is 1.7 folds higher than pure drug suspension. The antimicrobial activity of Spar-NLCs was better than the pure drug suspension and equivalent to the marketed formulation. Spar-NLC formulation did not showed any ocular damage, swelling, and redness in in -vivo Draize test. The ocular tolerance test (HET-CAM test) also suggests that the Spar-NLC formulation and its excipients were nonirritant to the ocular tissues. The formulation was found to be stable over the three month of stability study. Therefore, this work strongly suggest that Spar-NLCs has higher penetration and extended release of drug which can be effectively used in prevention of bacterial conjunctivitis.

Dissolution profiles of fenbendazole from binary solid dispersions: a mathematical approach

Aim: Understanding a drug dissolution process from solid dispersions (SD) to develop formulations with predictable in vivo performance. Materials & methods: Dissolution data of fenbendazole released from the SDs and the control physical mixtures were analyzed using the Lumped mathematical model to estimate the parameters of pharmaceutical relevance. Results: The fit data obtained by Lumped model showed that all SDs have a unique dissolution profile with an error of ±4.1% and an initial release rate 500-times higher than the pure drug, without incidence of drug/polymer ratio or polymer type. Conclusion: The Lumped model helped to understand that the main factor influencing the fenbendazole release was the type formulation (SD or physical mixture), regardless of the type or amount of polymer used.