Lyophilized mixed micelles of exemestane: A novel paradigm to improve its absorption and anticancer activity.

The objective of the present investigation was to prepare and optimize lyophilized mixed micelles (Lyp-EXE-MMs) of exemestane (EXE) with improved solubility, bioavailability, in vivo anticancer activity, and physical stability, by using various cryoprotectants. The prepared lyophilized mixed micelles were characterized by various techniques, including dynamic light scattering, zeta potential, powdered X-ray diffraction, differential scanning calorimetry (DSC), nuclear magnetic resonance (1 H NMR), transmission electron microscopy (TEM), and so on. Thereafter, the lyophilized micelles were evaluated for ex vivo permeation, in vitro drug release and gene/protein expression (RT-PCR and Western blot analysis) in MCF-7 breast cancer cells. The developed formulation was also investigated for its in vivo anticancer study in BALB/c mice with induced breast cancer. The use of trehalose (10% w/w) was proven to be a suitable cryoprotectant for these micelles. Lyp-EXE-MMs were spherical, with a particle size of 42.9 ± 3.8 nm and a polydispersity index of 0.307 ± 0.122. Furthermore, % drug loading and % entrapment efficiency were found to be 5.8 ± 1.4 and 89.1 ± 1.1, respectively. Lyp-EXE-MMs showed sustained release behavior as compared to EXE-suspensions in SGF/SIF (pH 1.2 and 6.8) and phosphate buffer saline (pH 7.4). The micelles induced apoptosis through the regulation of BAX, BCL2, Caspase-3, p53, and CYP19A1 in MCF-7 cells, which was correlated to enhanced ex vivo drug permeation. Animals receiving EXE micelle formulations showed reduced tumor volume and improved survivability and pharmacokinetic parameters as compared to pure EXE. Lyp-EXE-MMs were found to withstand simulated harsh conditions of SGF/SIF during stability studies. The fabricated EXE micellar preparations hold a promising approach for breast cancer treatment.

Polymeric Precipitation Inhibitor Based Supersaturable Self-microemulsifying Drug Delivery System of Canagliflozin: Optimization and Evaluation.

BACKGROUND: The present investigation attempts to optimize Supersaturable lipid based formulation (SS SMEDDS) of Biopharmaceutical Classification System (BCS) class IV drug canagliflozin (CFZ) and evaluating the oral bioavailability of the formulation. METHODS: Preliminary screening revealed Poloxamer 188 to most effectively inhibit precipitation of CFZ after dispersion during in vitro supersaturation studies. Box Behnken Design was employed for designing different formulations, and various statistical analyses were done to select an appropriate mathematical model. The optimized formulation (OSS 1) was evaluated for in vitro drug release and ex vivo permeation studies to evaluate drug release and permeation rate. Pharmacokinetic studies have been carried out according to standard methodologies. RESULTS: The optimized formulation (OSS 1) containing 781.1 mg SS SMEDDS and 2.24% w/w Poloxamer 188 was developed at a temperature of 60°C, which revealed nano-globule size with negligible aggregation. Isothermal titration calorimetry revealed the thermodynamic state of formed microemulsion with negative ΔG. The optimized formulation was observed to possess physical stability under different stress conditions and acceptable drug content. In vitro dissolution of optimized SS SMEDDS revealed a higher dissolution rate of CFZ as compared to native forms of CFZ. The permeability of CFZ from optimized SS SMEDDS across various excised segments of rat intestine was observed to be multifold higher as manifested by 2.05-fold higher Cmax and 5.64- fold higher AUC0-36h following oral administration to Wistar rats. CONCLUSION: The results could be attributed to substantial lymphatic uptake and P-glycoprotein substrate affinity of CFZ in SS SMEDDS investigated through chylomicron and P-glycoprotein inhibition approach, respectively.

Evaluation of Bio-Mechanistic Behavior of Liquid Self-Microemulsifying Drug Delivery System in Biorelevant Media.

The aim of the study is to mechanistically investigate the drug loci, structural integrity, chemical interactions, and absorption behavior of the liquid self-microemulsifying drug delivery system (SMEDDS). The loci of drug molecules in self-forming microemulsions in biorelevant media (fasted state simulated gastric fluid and fed state simulated intestinal fluid) were investigated by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Chemical interactions were observed through attenuated total reflectance spectroscopy (ATR). The structural integrity of self-forming microemulsions in biorelevant media was determined by small angle X-ray scattering (SAXS) and fluorescence resonance energy transfer (FRET). Morphological features of self-forming microemulsion were determined by confocal laser scanning microscopy. In vitro, lipid digestion behavior was evaluated for particle size, zeta potential, free fatty acids (FFA), and drug released through standard protocols. In-house characterizations were determined through standard methodologies. 1H and 13C NMR revealed that drug loci were found in a majority in the oily core region in the self-forming microemulsion. The ATR signifies that no inherent chemical was observed in the liquid SMEDDS and drug-loaded self-microemulsions in the biorelevant media. Structural integrity was well maintained during the dispersive and digestive phases in the gastrointestinal lumen during lipolysis in biorelevant conditions, as revealed by SAXS and FRET. An in vitro digestion study in biorelevant conditions depicts no fluctuations in size and zeta potential with a predominant release of FFA and drug, and was to be revealed physiologically acceptable for clinical applications.

Enhanced oral bioavailability and anti-diabetic activity of canagliflozin through a spray dried lipid based oral delivery: a novel paradigm.

AIM: Canagliflozin (CFZ), a novel SGLT II antagonist, exhibits erratic absorption after oral administration. The current study entails development and evaluation of spray dried lipid based formulation (solid SMEDDS) for enhancing oral bioavailability and anti-diabetic activity of CFZ. METHODS: Solid SMEDDS developed through spray drying containing Neusilin US2 as an adsorbent. The formed solid SMEDDS were characterized for physicochemical and solid state attributes. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to confirm the spherical morphology. In vitro dissolution, ex vivo permeability and in vivo pharmacokinetic studies were conducted to determine the release rate, permeation rate and absorption profile of CFZ, respectively. Pharmacodynamic studies were done as per standard protocols. RESULTS: The optimized solid SMEDDS exhibited acceptable practical yield and flow properties and is vouched with enhanced amorphization, nanoparticulate distribution and acceptable drug content. The spherical morphology of solid SMEDDS and reconstituted SMEDDS were confirmed in SEM and TEM, respectively. In vitro dissolution studies revealed multi-fold release behavior in CFZ in various dissolution media, whereas, remarkable permeability was observed in jejunum segment of rat intestine. Pharmacokinetic studies of CFZ in solid SMEDDS demonstrated 2.53 and 1.43 fold enhancement in Cmax and 2.73 and 1.98 fold in AUC 0-24h, as compared to pure API and marketed formulation, respectively. Pharmacological evaluation of solid SMEDDS revealed enhanced anti-diabetic activity of CFZ through predominant SGLT II inhibition in rats, as evident from evaluation of biochemical levels, urinary glucose excretion studies and SGLT II expression analysis. CONCLUSION: The current work describes significant improvement biopharmaceutical properties of CFZ in solid SMEDD formulation. Graphical abstract Graphical Abstract: Enhanced oral bioavailability and anti-diabetic activity of canagliflozin through a spray dried lipid based oral delivery: a novel paradigm.

Polymeric precipitation inhibitor as an effective trigger to convert supersaturated into supersaturable state in vivo.

The supersaturated state of the drug in vivo is thermodynamically unstable resulting in a delayed response and reduced efficacy. The use of polymeric precipitation inhibitor (PPI) has been demonstrated as an effective trigger for the conversion of supersaturated state to supersaturable state for improving solubilization, thermodynamic maintenance of drug concentration and oral absorption of poorly water-soluble compounds. PPI retards drug precipitation and provides a kinetically stabilized supersaturation state for an extended period in gastric and intestinal fluids. However, the selection of appropriate PPI and understanding its mechanism is a challenge for formulating a stable pharmaceutical formulation. The present review is aimed at understanding the intricacies of selecting PPIs and their applications in pharmaceutical formulations.

Self-microemulsifying Drug Delivery System for Problematic Molecules: An Update.

BACKGROUND: The poor bioavailability of a problematic molecule is predominantly due to its high lipophilicity, low solubility in gastric fluids and/or high fist pass metabolism. Self microemulsifying drug delivery system (SMEDDS), a lipidic type IV nano-formulation has been of interest in the field of pharmaceutical research due to its potential for tailoring the physicochemical properties of pharmaceutical molecules. METHODS: This review provides insights on various recent innovations and reports from the past seven years (2012-2019) of self-emulsifying formulations for the delivery of various types of poorly soluble drugs, phytoconstituents and high molecular peptides and gives exhaustive details of the outcome of the endeavors in this field. RESULTS: Various types of innovative formulations have been molded from SMEDDS like selfemulsifying powders, granules, tablets, pellets, eutectic and cationic formulations. Till date, many research reports and patents have been filed on self-emulsifying dosage forms and many formulations have gained US-FDA approvals which are summarized in the review article. CONCLUSION: This review content highlighted the increasing scope of SMEDDS in augmenting the physiochemical properties of an API, the variegated formulation types and the attributes of API that can be improved by SMEDD based formulations.

Role of Porous Carriers in the Biopharmaceutical Performance of Solid SMEDDS of Canagliflozin.

OBJECTIVE: The aim of the present investigation entails the development of solid SMEDDS for improving the oral bioavailability of canagliflozin using porous carriers. The previous patent (WO2017046730A1) was based on enhanced solubility of canagliflozin through co-crystal formation. METHODS: Preconcentrates were prepared by employing Lauroglycol (80 mg), Tween 80 (300 mg) and Transcutol P (120 mg) and successfully adsorbed onto various hydrophilic and hydrophobic carriers. The prepared solid SMEDDS were characterized for various parameters to determine the optimized formulation. In vitro, ex vivo and in vivo studies were carried out to determine drug release kinetics, permeation and absorption rate, respectively. Stability of the formulation was investigated at 45°C/75% RH. RESULTS: The solid preconcentrates prepared with hydrophobic carriers exhibited desired attributes in a uniform range. Neusilin adsorbed solid SMEDDS (S(N)SMEDDS) portrayed enhanced amorphization in XRD and DSC studies and found to be physically compatible in FTIR studies. SEM revealed colloidal particles having spherical morphology with negligible aggregation. Ex vivo permeation rate of the drug across excised intestinal segments (duodenum, jejunum, ileum and colon) was observed to be 3.72, 5.85, 4.51 and 3.0-fold, respectively, as compared to pure drug. TEM of reconstituted SMEDDS indicated nano-sized globules with negligible coalescence. Enhanced in vitro dissolution rate of optimized solid SMEDDS manifested in bioavailability enhancement of 167.54% and 188.98%, as compared to pure drug and marketed product. These studies further substantiate the lymphatic uptake of SMEDDS through chylomicron flow blocking approach. Establishment of Level A IVIVC showed a uniform correlation between the in vitro dissolution efficiency and in vivo pharmacokinetic parameters. CONCLUSION: The present investigation reveals the immense potential of solid SMEDDS in augmenting the oral bioavailability profile of poorly water-soluble drug canagliflozin.

Improved pharmacokinetic and pharmacodynamic attributes of artemether-lumefantrine-loaded solid SMEDDS for oral administration.

OBJECTIVES: To evaluate the in-vivo efficacy of solid SMEDDS containing combination of artemether and lumefantrine. METHODS: Formulation development of solid SMEDDS containing combination of artemether and lumefantrine was carried out using spray drying technique. These S-SMEDDS were evaluated for reduction in parasitemia and mortality as well as subacute toxicity in mice. Haematology, biochemical parameters and histopathology were performed for evaluating safety of formulation. Pharmacokinetic characterization of both drugs was performed after oral administration in rats. KEY FINDINGS: Optimized solid SMEDDS containing low, medium and high dose were more effective in reducing parasitemia and mortality of mice as compared to marketed tablets containing high dose of these drugs. Single oral administration of solid SMEDDS containing high-dose combination could maintain plasma concentration of lumefantrine above the minimum effective concentration for ≈4 days. CONCLUSIONS: Solid SMEDDS containing low-, medium- and high-dose combination of artemether and lumefantrine are more effective than marketed tablets.

Antimalarial solid self-emulsifying system for oral use: in vitro investigation.

AIM: The low aqueous solubility of artemether and lumefantrine makes them less bioavailable. It is expected that by formulating self-microemulsifying drug-delivery systems (SMEDDS), their aqueous solubility and absorption will thus be enhanced. Results & methodology: Optimized liquid SMEDDS containing artemether and lumefantrine was adsorbed on Neusilin US2® employing spray drying technique to convert it into solid SMEDDS. Almost 90% of both drugs were released within 15 min in their respective official dissolution media. Drug assay and dissolution rate of solid SMEDDS remained unaltered after 3-month storage at 40°C and 75% relative humidity. CONCLUSION: Reconstitution of solid SMEDDS in water yielded microemulsion with a globule size of 67.74 nm. Complete and faster in vitro release of both drugs from solid SMEDDS was observed as compared with that from marketed tablets.

Microemulsion Transdermal Formulation for Simultaneous Delivery of Valsartan and Nifedipine: Formulation by Design.

The objective of the study was to optimize the proportion of different components for formulating oil in water microemulsion formulation meant for simultaneous transdermal delivery of two poorly soluble antihypertensive drugs. Surface response methodology of Box-Behnken design was utilized to evaluate the effect of two oils (Captex 500 - x1 and Capmul MCM - x2) and surfactant (Acrysol EL135 - x3) on response y1 (particle size), y2 (solubility of valsartan), and y3 (solubility of nifedipine). The important factors which significantly affected the responses were identified and validated using ANOVA. The model was diagnosed using normal plot of residuals and Box-Cox plot. The design revealed an inverse correlation between particle size and concentration of Capmul MCM and Acrysol EL 135. However, an increase in concentration of Captex 500 led to an increase in particle size of microemulsion. Solubility of valsartan decreased while that of nifedipine increased with increase in concentration of Captex 500. Capmul MCM played a significant role in increasing the solubility of valsartan. The effect of Acrysol EL 135 on solubility of both drugs, although significant, was only marginal as compared to that of Captex 500 and Capmul MCM. The optimized microemulsion was able to provide an enhancement ratio of 27.21 and 63.57-fold for valsartan and nifedipine, respectively, with respect to drug dispersion in aqueous surfactant system when evaluated for permeation studies. The current studies candidly suggest the scope of microemulsion systems for solubilizing as well as promoting the transport of both drugs across rat skin at an enhanced permeation rate.

Understanding pharmaceutical polymorphic transformations II: crystallization variables and influence on dosage forms.

Excipients or formulation variables have often been exploited to improve stability, modify release, or improve physicochemical properties of dosage forms. In pharmaceutical field, it is generally expected that excipients work at macromolecular level where they might influence the crystal structure of a solid. These polymers/colloidal particles may modify the rate and direction of crystal growth. It has also been observed, that different polymorphic crystals exhibit different colors on exposure to same colorant, predominantly due to difference in surface pH of different crystal lattices. Apart from physicochemical affect, crystal habit also influences pharmacokinetic parameters of the dosage form. Crystals with smaller size or lower lattice energy have shown to exhibit higher bioavailability with faster rate of release.

Understanding pharmaceutical polymorphic transformations I: influence of process variables and storage conditions.

The active pharmaceutical ingredient (API) of a dosage form is affected by number of mechanical and environmental factors which have a tendency to alter its crystalline state. Polymorphic transitions have been observed to occur during various unit operations like granulation, milling and compression. Forces of pressure, shear and temperature have an ability to induce alterations in crystal habit. A conversion in polymorphic form during a unit operation is very likely to affect the handling of API in the subsequent unit operation. Transitions have also been observed during storage of formulations where the relative humidity and temperature play a major role. An increase in temperature during storage can dehydrate or desolvate the crystal and hence produce crystal defects, whilst, high humidity conditions produce higher molecular mobility leading to either crystallization of API or alteration of its crystalline form.

A critical appraisal of microemulsions for drug delivery: part II.

Microemulsions are thermodynamically stable, optically transparent isotropic solutions of oil and water successfully formulated by using a combination of suitable surfactant and cosurfactant. The solubilization power of microemulsions for lipophilic, hydrophilic and amphiphilic solutes form a viable approach for enhancing the bioavailability of hydrophobic drugs and percutaneous permeation of poorly permeable drugs, mainly due to the large area per volume ratio available for mass transfer. Microemulsions have emerged as novel vehicles for drug delivery due to their versatile applications. They allow sustained release for topical, oral, nasal, intravenous, ocular, parenteral and other administration routes of drugs. They also offer a relevant application platform for improving target specificity, therapeutic activity, and reducing toxicity of drugs.

Anti-cancer, pharmacokinetic and biodistribution studies of cremophor el free alternative paclitaxel formulation.

PURPOSE: The aim of the present investigation is to determine the in vivo potential of previously developed and optimized Cremophor EL free paclitaxel (CF-PTX) formulation consisting of soya phosphatidylcholine and biosurfactant sodium deoxycholate. CF-PTX was found to have drug loading of 6 mg/ml similar to Cremophor EL based marketed paclitaxel formulation. In the present study, intracellular uptake, repeated dose 28 days sub-acute toxicity, anti-cancer activity, biodistribution and pharmacokinetic studies were conducted to determine in vivo performance of CF-PTX formulation in comparison to marketed paclitaxel formulation. METHODS: Intracellular uptake of CF-PTX was studied using A549 cells by fluorescence activated cell sorting assay (FACS) and fluorescence microscopy. In vivo anti-cancer activity of CF-PTX was evaluated using Ehrlich ascites carcinoma (EAC) model in mice followed by biodistribution and pharmacokinetic studies. RESULTS: FACS investigation showed that fluorescence marker acridine orange (AO) solution showed only 19.8±1.1% intracellular uptake where as significantly higher uptake was observed in the case of AO loaded CF-PTX formulation (85.4±2.3%). The percentage reduction in tumor volume for CF-PTX (72.5±2.3%) in EAC bearing mice was found to be significantly (p<0.05) higher than marketed formulation (58.6±2.8%) on 14th day of treatment. Pharmacokinetic and biodistribution studies showed sustained plasma concentration of paclitaxel depicted by higher mean residence time (MRT; 18.2±1.8 h) and elimination half life (12.8±0.6 h) with CF-PTX formulation as compared to marketed formulation which showed 4.4±0.2 h MRT and 3.6±0.4 h half life. The results of the present study demonstrated better in vivo performance of CF-PTX and this formulation appears to be a promising carrier for sustained and targeted delivery of paclitaxel.

Sulfation of Aegle marmelos gum: synthesis, physico-chemical and functional characterization.

The present investigation was aimed at optimizing the conditions for preparing sulfated derivative of gum obtained from partially ripe fruits of Aegle marmelos. Elemental analysis, FTIR-ATR and NMR studies confirmed successful sulfation. The ratio of chlorosulfonic acid to pyridine exerted maximum influence on the degree of substitution followed by reaction temperature and reaction time. The sulfated derivative showed higher swelling in both acidic and alkaline pH as compared to unmodified gum. It also possessed higher negative zeta potential, higher viscosity, work of shear, firmness, consistency, cohesiveness and index of viscosity as compared to both unmodified gum as well as sodium alginate. Sulfated derivative was superior to unmodified gum and sodium alginate in terms of antimicrobial and anticoagulant activity. The sulfated sample appears to be a potential substitute over the unmodified gum sample and sodium alginate for modulating physicochemical properties of food and drug release dosage forms.

Tight junctions in skin: new perspectives.

Tight junctions (TJs) are intercellular contacts that seal the space between the individual cells of an epithelial sheet or stratifying epithelia, such as the epidermis, so that they can collectively separate tissue compartments. Intercellular junctions, such as adherens and TJs, play a crucial role in the formation and maintenance of epithelial and endothelial barriers. A variety of components including claudins, occludin, tricellulin, zonula occluden proteins and junctional adhesion molecules have been identified in complex localization patterns in mammalian epidermis. In several skin diseases that are characterized by impaired skin barrier function, altered proliferation/differentiation of the epidermis and/or infiltration of inflammatory cells, altered expression patterns of TJ proteins have been observed. This review is aimed at providing an insight into the molecular composition, tools for identification and understanding the role of TJs in skin diseases and barrier function regulation.

Hot melt granulation: a facile approach for monolithic osmotic release tablets.

The aim of this work was to develop and evaluate an extended release matrix tablet of glipizide (GP), an oral hypoglycemic agent. Matrices of GP were prepared using microcrystalline cellulose Avicel(™) PH 112, sodium chloride (SC) and polyethylene glycol 6000 (PEG). The content of Kollidon SR (KR), hydroxypropyl methylcellulose K4M premium CR grade (HM) and polyethylene oxide WSR 303 (PO) and/or magnesium hydroxide (MH) was varied in different formulations. All the formulations were processed by hot melt granulation technique. GP release was observed to be influenced by the amount of SC and MH present in the core formulation. The matrix tablets were coated with a solution containing combination of cellulose acetate 398.10 (CA) and PEG. The release of GP was observed to be inversely proportional to the weight of the coating membrane. Matrices containing PO in combination with SC and MH (14.28:8.56) showed significantly higher degree of hydration and swelling that was evident in the surface texture as visualized by scanning electron microscopy (SEM). Results of SEM studies confirmed the presence of pores in the semi-permeable coating membrane from where the GP release would have occurred. The release of GP from this formulation was similar to that of the marketed extended release tablet as judged from similarity factor (f2) analysis, which yielded a value of 74.7. The optimized formulation was found to be stable when tested according to long term and accelerated storage conditions of ICH guidelines upto 3 months.

Fabrication and optimization of fast disintegrating tablets employing interpolymeric chitosan-alginate complex and chitin as novel superdisintegrants.

The objective of the present work was to optimize the formulation of fast disintegrating tablets (FDTs) of ondansetron HCl containing novel superdisintegrants, possessing sufficient mechanical strength and disintegration time comparable to those containing crospovidone or croscarmellose sodium. The FDTs were formulated using a novel superdisintegrant (chitosan-alginate (1:1) interpolymer complex and chitin) to achieve a sweet tasting disintegrating system. The results revealed that chitin (5-20%) increased the porosity and decreased the DT of tablets. At higher concentrations chitin maintained tablet porosity even at 5.5 kg crushing strength. Ondansetron HCl was found to antagonize the wicking action of glycine. Further, evaluation of the mechanism of disintegration revealed that glycine transported the aqueous medium to different parts of the tablets while the chitosan-alginate complex swelled up due to transfer of moisture from glycine. This phenomenon resulted in breakage of the tablet within seconds. For preparing optimized FDTs, the reduced model equations generated from Box-Behnken design (BBD) were solved after substituting the known disintegration time of FDTs containing superdisintegrants in the reduced model equations. The results suggested that excipient system under investigation not only improved the disintegration time but also made it possible to prepare FDTs with higher crushing strength as compared to tablets containing known superdisintegrants.

Chitosan-carboxymethyl tamarind kernel powder interpolymer complexation: investigations for colon drug delivery.

The present study was aimed at evaluating the possible use of inter polymer complexed (IPC) films of chitosan (CH) and carboxymethyl tamarind kernel powder (CMTKP) for colon release of budesonide. Viscosity analysis of the supernatant liquid obtained after reacting CH and CMTKP in different proportions revealed 40:60 to be the optimum stoichiometric ratio. The FTIR spectra of IPC films formed from 50:50 or 40:60 ratio of CH:CMTKP did not reveal any reduction in the peaks at 1560cm(â1) and 1407cm(â1) after exposure to pH 1.2, suggesting resistance of the interaction between âCOO(â) groups of CMTKP and âNH(3) (+) groups of CH to gastric pH. Tablets containing Avicel pH 102 as diluent and coated to a weight gain of 10%, w/w with aqueous solutions of 40:60 or 50:50 ratio of CH:CMTKP did not release budesonide in pH 1.2 buffer. Histopathology of the rat colon after oral administration of these IPC film coated tablets revealed significantly greater (p<0.05) reduction in TNBS-induced ulcerative colitis as compared to that after administration of uncoated tablets. The Cmax of budesonide achieved after oral administration of these IPC film coated tablets was comparable to that observed after administration of uncoated tablets. The results strongly indicate versatility of CH-CMTKP IPC films to deliver budesonide in the colon.