Enhanced bioavailability of exemestane via proliposomes based transdermal delivery

Development and Validation of a Robust RP-HPLC Method for the Simultaneous Analysis of Exemestane and Thymoquinone and Its Application to Lipid-Based Nanoformulations

The present study describes the development and validation of a simple and rapid HPLC method for the simultaneous quantification of exemestane and thymoquinone. The separation of both compounds was performed on a 5 μ C-18 column utilizing phase A as water/methanol (45:5 v/v) and phase B as acetonitrile (50 v/v) (total ratio of A/B = 40:60 v/v) in isocratic elution mode as the mobile phase at a flow rate of 0.8 mL/min. Further, the Box-Behnken design was used for optimizing the analytical method. The proposed method was validated for various parameters, and all parameters were found to be within an acceptable range. The simultaneous detection of both drugs was monitored at 243 nm with a retention time of 5.73 and 6.93 min, respectively. Moreover, the forced degradation studies were conducted under various stress conditions, and the relevance of the validated RP-HPLC method was further explored for the estimation of drugs from lipid-based nanoformulation. Taken together, the study construed the development of an efficient and robust method that could be used for the quantification of these agents in various in vitro as well as in vivo models.

Review on novel targeted enzyme drug delivery systems: enzymosomes

The goal of this review is to present enzymosomes as an innovative means for site-specific drug delivery. Enzymosomes make use of an enzyme's special characteristics, such as its capacity to accelerate the reaction rate and bind to a particular substrate at a regulated rate. Enzymosomes are created when an enzyme forms a covalent linkage with a liposome or lipid vesicle surface. To construct enzymosomes with specialized activities, enzymes are linked using acylation, direct conjugation, physical adsorption, and encapsulation techniques. By reducing the negative side effects of earlier treatment techniques and exhibiting efficient medication release, these cutting-edge drug delivery systems improve long-term sickness treatments. They could be a good substitute for antiplatelet medication, gout treatment, and other traditional medicines. Recently developed supramolecular vesicular delivery systems called enzymosomes have the potential to improve drug targeting, physicochemical characteristics, and ultimately bioavailability in the pharmaceutical industry. Enzymosomes have advantages over narrow-therapeutic index pharmaceuticals as focusing on their site of action enhances both their pharmacodynamic and pharmacokinetic profiles. Additionally, it reduces changes in normal enzymatic activity, which enhances the half-life of an enzyme and accomplishes enzyme activity on specific locations.

Microfluidic synthesis of lipid-based nanoparticles for drug delivery: recent advances and opportunities

Microfluidic technologies are revolutionizing the synthesis of nanoscale lipid particles and enabling new opportunities for the production of lipid-based nanomedicines. By harnessing the benefits of microfluidics for controlling diffusive and advective transport within microfabricated flow cells, microfluidic platforms enable unique capabilities for lipid nanoparticle synthesis with precise and tunable control over nanoparticle properties. Here we present an assessment of the current state of microfluidic technologies for lipid-based nanoparticle and nanomedicine production. Microfluidic techniques are discussed in the context of conventional production methods, with an emphasis on the capabilities of microfluidic systems for controlling nanoparticle size and size distribution. Challenges and opportunities associated with the scaling of manufacturing throughput are discussed, together with an overview of emerging microfluidic methods for lipid nanomedicine post-processing. The impact of additive manufacturing on current and future microfluidic platforms is also considered.

Superiority of Microemulsion-based Hydrogel for Non-Steroidal Anti-Inflammatory Drug Transdermal Delivery: A Comparative Safety and Anti-nociceptive Efficacy Study

Non-steroidal anti-inflammatory drugs (NSAIDs) represent the foundation of pain management caused by inflammatory disorders. Nevertheless, their oral administration induces several side effects exemplified by gastric ulceration, thus, delivering NSAIDs via the skin has become an attractive alternative. Herein, microemulsion-based hydrogel (MBH), proliposomal, and cubosomal gels were fabricated, loaded with diclofenac, and physicochemically characterized. The sizes, charges, surface morphologies, and the state of diclofenac within the reconstituted gels were also addressed. The release pattern and ex-vivo permeation studies using Franz cells were performed via the rat abdominal skin. The formulations were assessed in-vivo on mice skin for their irritation effect and their anti-nociceptive efficacy through the tail-flick test. Biosafety study of the optimal gel was also pointed out. The gels and their dispersion forms displayed accepted physicochemical properties. Diclofenac released in a prolonged manner from the prepared gels. MBH revealed a significantly higher skin permeation and the foremost results regarding in-vivo assessment where no skin irritation or altered histopathological features were observed. MBH further induced a significant anti-nociceptive effect during the tail-flick test with a lower tendency to evoke systemic toxicity. Therefore, limonene-containing microemulsion hydrogel is a promising lipid-based vehicle to treat pain with superior safety and therapeutic efficacy.

A drift on liposomes to proliposomes: recent advances and promising approaches

Liposomes are nano-structured vesicles, made up of phospholipids that provide active ingredients at the site of action at a predetermined rate and add the advantage of the sustained-release formulation. Liposomes have stability issues that tend to agglomerate and fuse upon storage, which reflects their drawback. Hence to overcome the aggregation, fusion, hydrolysis, and/or oxidation problems associated with liposomes a new technology named Proliposomes has been introduced. Proliposomes are defined as carbohydrate carriers coated with phospholipids, which upon addition of water generate liposomes. The objective of the review is to cover the concept of proliposomes for pulmonary or alveolar delivery of drugs and compare it with that of liposomes; highlight the methods used for preparations along with the characterization parameters. This is the first systematic review that covers the categorization of liposomes, characteristic methods, and recent examples of drugs from 2015 to 2021, supplied in form of proliposomes to the macrophages as well as others and offers an advantage over the free drug by offering a prolonged drug release and sufficient bioavailability in addition to overcome the stability issues related to liposomes. Since this is a very new technology and many scientists are continuously working in this field to make the drug available for clinical trials and ultimately in the market for the targeted delivery of drugs with better storage life.HIGHLIGHTSProliposomes as an alternative to overwhelm the stability and storage-related issues of liposomes.Anhydrous carbohydrate carriers are utilized for proliposomal preparation.Inhaled delivery of drugs as solid lipid nanoparticles offers a significant impact on pulmonary tract infections, particularly in cystic fibrosis.Size of liposomes attained after proliposome hydrolysis is critical for drug delivery via respiration.

Current trends in chitosan based nanopharmaceuticals for topical vaginal therapies

Large surface area, rich vascularisation, well defined mucous membrane, balanced pH and relatively low enzymatic activity makes vagina a suitable site for drugs associated with women's health issues like Urinary tract infection (UTI) and vaginal infections. Therapeutic performance of intravaginal dosage forms largely depends on the properties of polymers and drugs. Chitosan (CS) because of its unique physical, chemical, pharmaceutical and biopharmaceutical properties have received a great deal of attention as an essential component in vaginal drug delivery systems. Further the presence of free amino and hydroxyl groups on the chitosan skeleton allows easy derivatization under mild conditions to meet specific application requirements. Moreover, CS-based nanopharmaceuticals like nanoparticles, nanofiber, nanogel, nanofilm, liposomes and micelles are widely studied to improve therapeutic performance of vaginal formulations. However, susceptibility of CS to the acidic pH of vagina, poor loading of hydrophobic drugs, rapid mucosal turn over are the key issues need to be addressed for successful outcomes. In this review, we have discussed the application of CS and CS derivatives in vaginal drug delivery and also highlight the recent progress in chitosan based nanocarrier platforms in terms of their limitations and potentials.

Proniosomal Formulation Encapsulating Pomegranate Peel Extract for Nutraceutical Applications

In this study, pomegranate peel as a traditional natural remedy was extracted and encapsulated in proniosomal systems in order to improve its stability against harsh environmental conditions. Pomegranate peel was extracted by using sonication as a green extraction technology and the antioxidant activity of the obtained extract was evaluated to be 85.37% by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Proniosomal powder was prepared based on the slurry method with a mixture of non-ionic surfactants namely span 60 and tween 20 in combination with cholesterol as a bilayer stabilizer. Proniosome-derived niosomes were achieved by hydration of the powder with water. The obtained vesicles were evaluated for their particle size, morphological observations, entrapment efficiency, cytotoxicity assay, DPPH antioxidant activity and, physical stability at 4 °C for 28 days. The results demonstrated that the proniosome-derived niosomes were of small size (198.16 nm for unloaded and 411.3 for extract loaded), quite homogeneous (PDI = 0.188 for unloaded and 0.216 for loaded) with highly negative charged spherical vesicles and showed appropriate physical stability during the time of storage. The encapsulation efficiency was 68.43±0.24% and the cytotoxicity assay proved that the formulations were not toxic against 3T3 fibroblast cells in the applied concentration.

Thermoresponsive liquid crystalline formulation of Exemestane: Design and structural characterization

Exemestane (EXE), a drug used for the treatment of breast cancer, has limited aqueous solubility of 0.08 mg/mL and log P∼ 4.22. The only available marketed formulation in form of tablets possess limitations of poor oral absorption (∼ 42 %), low solubility, extensive hepatic metabolism and numerous adverse effects due to its peripheral absorption. In order to address these issues, an alternative route of topical application is attempted through a lamellar liquid crystal based formulation. Pluronic® was used as stabilizer due to its higher surface activity and gelling properties. The solubility enhancement of EXE was achieved using liquid crystal formulation. We have investigated the effect of concentration of oil, S_mix (surfactant - cosurfactant mixture) and EXE on lattice parameter, rheology and drug release for various combinations of the formulation. The small angle x-ray scattering (SAXS) measurement demonstrated an evidence of a lamellar structure with lattice parameter ∼15 nm, which increases with corresponding increase in oil and EXE due to increase in hydrophobic interactions leading to an expansion of lamella. The inter lamellar distance decreases at higher surfactant concentration, due to the distribution of the same amount of oil and drug within larger concentration of surfactant molecules. The rheology measurement exhibited gel like properties at low shear rate indicating soft gel formation, which converts to Newtonian type flowing liquid at higher shear rate. At constant S_mix with increasing oil content, the viscosity decreases, which is attributed to the dilution of the lamellar structures with oil. The temperature sweep rheology reveals a change in the viscosity near physiological temperature, which may be attributed to the structural transition of lamellae. The formulation remains gel like at room temperature, which aids in proper application to skin and converts it to free flowing liquid above 37 °C. The invitro drug release of optimized formulation for 24 h was ∼ 38 % at 37 °C, which increased to 50 % at 42 °C. Accordingly, this formulation containing thermoresponsive lamellar liquid crystal gels of EXE represents a viable option for hyperthermia induced enhanced drug release. The characteristic and advantageous features offered by this formulation includes improved bioavailability of EXE due to enhanced solubility, permeability and absorption.

Development of Darunavir proliposome powder for oral delivery by using Box-Bhenken design

The aim of this study is to develop Darunavir (DRV) proliposome powder for oral delivery. Darunavir-loaded oral proliposome powder (OPP) was prepared by a solvent evaporation technique with varying independent variables at three different levels. Based on different levels, proliposome powder formulation was optimized by using Box-Behnken design. The formulations were analyzed for its size distribution, entrapment efficiency, and surface morphology. Optimized proliposome batch A was evaluated for physical parameter, morphological parameters, entrapment efficiency, followed by in vitro, ex vivo, and in vivo studies. Oral proliposome powder showed good micromeritic properties with angle of repose was less than 30°, Carr's index and Hausner's ratio were also less than 21 and 1.25, respectively. The mean size of the vesicles was in the range of 180-290 nm. The assay and entrapment efficiency of pro-liposome powder formulations were 79.00 ± 0.2 and 93.46 ± 0.2%, respectively. In vitro release of DRV proliposome powder was 78.17 ± 0.1% after 24 h which shows good release from the vesicle of proliposome. Ex vivo permeation study shows 58.11% enhancement which shows good permeation. The optimize batch A of proliposome powder indicated 50% enhancement in the relative bioavailability as compared to the DRV suspension. The results showed that proliposome powder containing DRV can efficiently deliver in to the blood stream. This drug delivery system has been designed as a novel platform for potential oral delivery of drugs having poor water solubility and high first-pass metabolism.

Development and Evaluation of Curcumin Liquid Crystal Systems for Cervical Cancer

Curcumin is a hydrophobic compound with good anti-proliferative, anti-oxidative, and anti-cancer properties but has poor bioavailability. Liquid crystals (LC) can accommodate both hydrophilic and hydrophobic drugs. The aim of this study was to formulate and evaluate a novel vaginal drug delivery system for cervical cancer using a curcumin LC system. The curcumin LC system was formulated using surfactant, glycerol, and water together with curcumin. Three types of surfactants were used to optimize the formulation, i.e., Tween 80, Cremphor EL, and Labrasol. The optimized formulations were subjected to physicochemical analysis, and their efficacy was evaluated in HeLa cells. The pH of the formulations was in the range of 3.91–4.39. Environmental scanning electron microscopy (ESEM) observations revealed spherical as well as hexagonal micelles. In vitro release of LC curcumin from vaginal simulated fluid (VSF, pH 4.5) showed a release from 20.47% to 87.25%. The IC50 of curcumin in HeLa cells was 22.5 μg/mL, while the IC25 and IC75 were 6.5 μg/mL and 35μg/mL, respectively. The cytotoxicity of the formulations was determined in comparison with liquid crystals without curcumin and pure curcumin by performing a t-test based on a significance level of p less than or equal to 0.05 (p ≤ 0.05). The curcumin LC system was able to release the required amount of drug and was effective against the cervical cancer cell line examined.

Preparation and characterization of nano amitriptyline hydrochloride particles by spray freeze drying

Aim: To investigate the enhancement of bioavailability by the usage of drug nanoparticles for increasing the efficacy of antidepressant therapeutic value. Materials & methods: Nano-amitriptyline HCI (AMT·HCl) particles were successfully prepared via a simple spray freeze drying (SFD) method. Results: The as-prepared nanoparticles are amorphous instead of crystalline. The mean size of AMT·HCl nanoparticles is 90 nm. In in vitro evaluation, AMT·HCl nanoparticles have greatly improved the dissolution compared with pure bulk materials, which have potential for enhancing human bioavailability and diminishing toxic effect. A nanoparticle formation mechanism was also proposed. Conclusion: These findings promote the development of antidepressant therapeutic evaluation based on the usage of AMT·HCl nanoparticles by SFD method and indicate that SFD is an alternative for a range of nanoparticle preparation in industrial pharmacy.

Development and evaluation of exemestane-loaded lyotropic liquid crystalline gel formulations

Introduction: The use of liquid crystalline (LC) gel formulations for drug delivery has considerably improved the current delivery methods in terms of bioavailability and efficacy. The purpose of this study was to develop and evaluate LC gel formulations to deliver the anti-cancer drug exemestane through transdermal route. Methods: Two LC gel formulations were prepared by phase separation coacervation method using glyceryl monooleate (GMO), Tween 80 and Pluronic® F127 (F127). The formulations were characterized with regard to encapsulation efficiency (EE), vesicle size, Fourier transform infrared (FTIR) spectroscopy, surface morphology (using light and fluorescence microscopy), in vitro release, ex vivo permeation, in vitro effectiveness test on MDA-MB231 cancer cell lines and histopathological analysis. Results: Results exhibited that the EE was 85%-92%, vesicle size was 119.9-466.2 nm while morphology showed spherical vesicles after hydration. An FTIR result also revealed that there was no significant shift in peaks corresponding to Exemestane and excipients. LC formulations release the drug from cellulose acetate and Strat-MTM membrane from 15%-88.95%, whereas ex vivo permeation ranges from 37.09-63%. The in vitro effectiveness study indicated that even at low exemestane concentrations (12.5 and 25 μg/mL) the formulations were able to induce cancer cell death, regardless of the surfactant used. Histopathological analysis thinning of the epidermis as the formulations penetrate into the intercellular regions of squamous cells. Conclusion: The results conjectured that exemestane could be incorporated into LC gels for the transdermal delivery system and further preclinical studies such as pharmacokinetic and pharmacodynamic studies will be carried out with suitable animal models.

Shell-crosslinked zein nanocapsules for oral codelivery of exemestane and resveratrol in breast cancer therapy

Aim: Oral administration of exemestane (EXM) and resveratrol (RES) for breast cancer therapy has been limited by their poor solubility and low permeability. Methods: In this study, these issues were tackled using zein nanocapsules (ZNCs) for oral EXM/RES codelivery combining drug solubilization within oily core and resistance to digestion via hydrophobic protein shell. Furthermore, higher oral stability and sustained release could be enabled by glutaraldehyde crosslinking of zein shell. Results & conclusion: EXM/RES-ZNCs showed enhanced cytotoxicity against MCF-7 and 4T1 breast cancer cells compared with free drug combination with higher selectivity to cancer cells rather than normal fibroblasts. In vivo, crosslinked EXM/RES-ZNCs markedly reduced the percentage increase of Ehrlich ascites mammary tumor volume in mice by 2.4-fold compared with free drug combination.

Adefovir dipivoxil loaded proliposomal powders with improved hepatoprotective activity: formulation, optimization, pharmacokinetic, and biodistribution studies

The present study aimed to prepare proliposomal formulae for improving the oral bioavailability of adefovir dipivoxil (AD), a nucleoside reverse transcriptase inhibitor effective against hepatitis B virus (HBV). The prepared proliposomal formulae were characterized for entrapment efficiency (E.E.%), vesicle size and in vitro drug release after reconstitution to conventional liposomes. The optimized formula (F9) with a maximum desirability value of 0.858 was selected having E.E.% of 71 ± 3.3% with an average vesicle size of 164.6 ± 5 nm. Moreover, the crystallization of AD within the optimized formula investigated via powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed the presence of the drug in an amorphous state within the lipid vesicles with enhanced stability over a storage period of 12 months. Thioacetamide-induced liver damage in rats evidenced by elevated liver enzymes was significantly improved after treatment with the optimum formula. Pharmacokinetic and biodistribution studies of formula F9 showed a higher accumulation of AD in the liver with enhanced bioavailability compared to AD suspension which highlights its potential advantage for an effective treatment of chronic HBV. Hence, proliposomal drug delivery is considered as a better choice for the oral delivery of AD.

HPLC Methods for Quantitation of Exemestane-Luteolin and Exemestane-Resveratrol Mixtures in Nanoformulations

Two HPLC-DAD assays for the simultaneous quantitation of exemestane (EXE) and resveratrol (RES)-Mix 1-and EXE and luteolin (LUT)-Mix 2-in novel breast cancer therapy nanoformulations were developed. Calibration curves 15-30 µg/mL and samples were injected through an Inertsil ODS-3 (250 × 4.6 mm, 5 µm) column. The gradient elution for Mix 1 was methanol : 0.05% (v/v) acetic acid in water (60 : 40 to 80 : 20, linear over 2 min), and for Mix 2, it was methanol : water (60 : 40 for 4 min, then ramped linearly to 90 : 10, over 12 min) pumped at 1.5 mL/min for 4 min, then 1 mL/min till the end of run. EXE, RES, LUT and flutamide (internal standard (IS)) were measured at 246, 307, 350 and 300 nm, respectively. For Mix 1, RES, EXE and IS eluted at 3.5, 6.8 and 7.4 min, respectively, while for Mix 2, LUT, EXE and IS eluted at 7.5, 11.4 and 12.7 min, respectively. The mean r(2) for the standard curves was ≥0.99, and percentage coefficient of variation and % error of the mean were <2. Both assays successfully quantitated Mix 1 and Mix 2 in their nanoformulations. The two developed assays were sensitive and selective for the analysis of EXE-LUT and EXE-RES mixtures in nanoformulations according to International Conference on Harmonization guidelines.

Steroidal and non-steroidal third-generation aromatase inhibitors induce pain-like symptoms via TRPA1

Use of aromatase inhibitors (AIs), exemestane, letrozole and anastrozole, for breast cancer therapy is associated with severe pain symptoms, the underlying mechanism of which is unknown. The electrophilic nature of AIs suggests that they may target the transient receptor potential ankyrin 1 (TRPA1) channel, a major pathway in pain transmission and neurogenic inflammation. AIs evoke TRPA1-mediated calcium response and current in rodent nociceptors and human cells expressing the recombinant channel. In mice, AIs produce acute nociception, which is exaggerated by pre-exposure to proalgesic stimuli, and, by releasing sensory neuropeptides, neurogenic inflammation in peripheral tissues. AIs also evoke mechanical allodynia and decreased grip strength, which do not undergo desensitization on prolonged AI administration. These effects are markedly attenuated by TRPA1 pharmacological blockade or in TRPA1-deficient mice. TRPA1 is a major mediator of the proinflammatory/proalgesic actions of AIs, thus suggesting TRPA1 antagonists for the treatment of pain symptoms associated with AI use.

AAPE proliposomes for topical atopic dermatitis treatment

CONTEXT

Anti-inflammatory effect of advanced adipose stem cell derived protein extract (AAPE) could be improved by minimising protein degradation.

OBJECTIVE

To develop a proliposomal formulation of AAPE for the treatment of topical atopic dermatitis.

MATERIALS AND METHODS

Proliposomal powder was manufactured by evaporating a solution of soy phosphatidyl choline, AAPE and Poloxamer 407 in ethanol under vacuum on sorbitol powder. Characterisation of proliposomes (zeta potential, diameter, stability and flowability) as well as in vivo efficacy in a dermatitis mouse model was investigated.

RESULTS AND DISCUSSION

Reconstitution of the proliposomal powder formed liposomes of 589 ± 3.6 nm diameter with zeta potential of -51.33 ± 0.36 mV. Protein stability was maintained up to 90 days at 25 °C as proliposomes. In vivo studies on atopic dermatitis mouse model showed a significant reduction in IgE levels after topical AAPE proliposome treatment.

CONCLUSION

AAPE proliposomes maintained protein stability and showed promising results for atopic dermatitis treatment.

Enhanced oral bioavailability of efavirenz by solid lipid nanoparticles: in vitro drug release and pharmacokinetics studies

Solid lipid nanoparticle is an efficient lipid based drug delivery system which can enhance the bioavailability of poorly water soluble drugs. Efavirenz is a highly lipophilic drug from nonnucleoside inhibitor category for treatment of HIV. Present work illustrates development of an SLN formulation for Efavirenz with increased bioavailability. At first, suitable lipid component and surfactant were chosen. SLNs were prepared and analyzed for physical parameters, stability, and pharmacokinetic profile. Efavirenz loaded SLNs were formulated using Glyceryl monostearate as main lipid and Tween 80 as surfactant. ESLN-3 has shown mean particle size of 124.5 ± 3.2 nm with a PDI value of 0.234, negative zeta potential, and 86% drug entrapment. In vitro drug release study has shown 60.6-98.22% drug release in 24 h by various SLN formulations. Optimized SLNs have shown good stability at 40°C ± 2°C and 75 ± 5% relative humidity (RH) for 180 days. ESLN-3 exhibited 5.32-fold increase in peak plasma concentration (C max) and 10.98-fold increase in AUC in comparison to Efavirenz suspension (ES).

Development of ketoprofen loaded proliposomal powders for improved gastric absorption and gastric tolerance: in vitro and in situ evaluation

The aim of the current investigation was to improve dissolution rate, gastric absorption and tolerance of a water insoluble non-steroidal anti-inflammatory drug ketoprofen by developing proliposomal powders. Ketoprofen proliposomal powders were prepared by solvent evaporation method with varying ratios of hydrogenated soyphosphatidyl choline (HSPC) and cholesterol. The prepared proliposomal powders were characterized for vesicle size, micromeritics, entrapment efficiency and in vitro dissolution behavior. Proliposomal powder (KPL3) composed of equimolar ratios of HSPC and cholesterol loaded on pearlitol SD 200 was selected as optimized formulation as it produced smaller liposomes (5.24 ± 1.35 μm) upon hydration with highest entrapment efficiency (53.16 ± 0.06%). All proliposomal powders showed improved dissolution characteristics than pure drug, however dissolution of drug from KPL3 was found to be highest (91.17 ± 6.3) and which is about 24 times higher than pure ketoprofen within 5 min. The transformation of crystalline ketoprofen to amorphous form was confirmed by solid state characterization. The absorption rate per hour for pure ketoprofen and proliposomal formulation (KPL3) was assessed in the stomach by conducting in situ gastric absorption studies in Wistar rats and was found to be 27 ± 1.22 and 36.98 ± 1.95%, respectively. In conclusion, enhanced dissolution and gastric absorption rate of ketoprofen from proliposomal powders suggest them as potential candidate for oral bioavailability improvement of ketoprofen.

Provesicular granisetron hydrochloride buccal formulations: in vitro evaluation and preliminary investigation of in vivo performance

Granisetron hydrochloride (granisetron) is a potent antiemetic that has been proven to be effective in acute and delayed emesis in cancer chemotherapy. Granisetron suffers from reduced oral bioavailability (≈60%) due to hepatic metabolism. In this study the combined advantage of provesicular carriers and buccal drug delivery has been explored aiming to sustain effect and improve bioavailability of granisetron via development of granisetron provesicular buccoadhesive tablets with suitable quality characteristics (hardness, drug content, in vitro release pattern, exvivo bioadhesion and in vivo bioadhesion behavior). Composition of the reconstituted niosomes from different prepared provesicular carriers regarding type of surfactant used and cholesterol concentration significantly affected both entrapment efficiency (%EE) and vesicle size. Span 80 proniosome-derived niosomes exhibited higher encapsulation efficiency and smaller particle size than those derived from span 20. Also, the effect of %EE and bioadhesive polymer type on in vitro drug release and in vivo performance of buccoadhesive tablets was investigated. Based on achievement of required in vitro release pattern (20-30% at 2h, 40-65% at 6h and 80-95% at 12h), in vivo swelling behavior, and in vivo adhesion time (>14 h) granisetron formulation (F19, 1.4 mg) comprising HPMC:carbopol 974P (7:3) and maltodextrin coated with the vesicular precursors span 80 and cholesterol (9:1) was chosen for in vivo study. In vivo pharmacokinetic study revealed higher bioavailability of buccal formulation relative to conventional oral formulation of granisetron (AUC0-∞ is 89.97 and 38.18 ng h/ml for buccal and oral formulation, respectively). A significantly lower and delayed Cmax (12.09±4.47 ng/ml, at 8h) was observed after buccal application compared to conventional oral tablet (31.66±10.15 ng/ml, at 0.5 h). The prepared provesicular buccoadhesive tablet of granisetron (F19) might help bypass hepatic first-pass metabolism and improve bioavailability of granisetron with the possibility of reducing reported daily dose (2mg) and reducing dosing frequency.

Neuroprotective study of Nigella sativa-loaded oral provesicular lipid formulation: in vitro and ex vivo study

AIM

The aim of this research was to develop proniosome (niosomes) of Nigella sativa (NS) to improve its drug release, gastrointestinal (GI) permeation and neuroprotective activity.

MATERIALS AND METHODS

Proniosomes were prepared by thin film method using various compositions of nonionic surfactants, cholesterol, and phosphatidylcholine. The optimum influence of different formulation variables of NS such as surfactant type, phosphatidylcholine and cholesterol concentration were optimized for size and entrapment efficiency.

RESULTS AND DISCUSSION

Results indicated that prepared niosome showed smaller size with high entrapment efficiency. The permeation enhancement ratio was found to be 2.16 in comparison to control with maximum flux value obtained was 7.23 µg/cm(2)/h for formulation NS6. The in vivo study revealed that the niosomal dispersion significantly improved neuroprotective activity in comparison to standard and control formulation.

CONCLUSION

In conclusion, developed proniosomal formulation could be one of the promising delivery system for NS with better drug release and GI permeation profiles and improved neuroprotective activity and merits for further study.

Formulation and evaluation of guggul lipid nanovesicles for transdermal delivery of aceclofenac

Context. Most new drugs have low water solubility and liposome is an important formulation to administer such drugs; however, it is quite unstable and has negligible systemic absorption. Objective. Aceclofenac nanovesicles were made using guggul lipid for formulating stable transdermal formulation. Materials and Methods. Guggul lipid was formulated into vesicles along with cholesterol and dicetyl phosphate using film hydration method. The formulations were analyzed for physicochemical properties and stability. Then its skin permeation and anti-inflammatory activity were determined. Results. Both categories of vesicles (PC and GL) showed optimum physicochemical properties; however, accelerated stability study showed considerable differences. GL-1 was appreciably stable for over 6 months at 4°C. Corresponding gels (PCG-1 and GLG-1) showed C_max values at 4.98 and 7.32 μg/mL along with the T_max values at 4 and 8 hours, respectively. GLG-1 inhibited edema production by 90.81% in 6 hours. Discussion. PC liposomes are unstable at higher temperature and upon longer storage. The formulation with higher lipid content (GL-1) showed good drug retention after 24 hours and appreciable stability both at higher temperature and for longer duration. Guggul lipid being a planar molecule might be stacked in vesicle wall with cholesterol. Conclusion. The composition of the nanovesicle played an important role in stability and drug permeation. Guggul lipid is suitable for producing stable vesicles.

Proliposome powders for enhanced intestinal absorption and bioavailability of raloxifene hydrochloride: effect of surface charge

The primary goal of the present study was to investigate the combined prospective of proliposomes and surface charge for the improved oral delivery of raloxifene hydrochloride (RXH). Keeping this objective, the present systematic study was focused to formulate proliposomes by varying the ratio of hydrogenated soyphosphatidylcholine and cholesterol. Furthermore, to assess the role of surface charge on improved absorption of RXH, anionic and cationic vesicles were prepared using dicetyl phosphate and stearylamine, respectively. The formulations were characterized for size, zeta potential and entrapment efficiency. The improved dissolution characteristics assessed from dissolution efficiency, mean dissolution rate were higher for proliposome formulations. The solid state characterization studies indicate the transformation of native crystalline form of the drug to amorphous and/or molecular state. The higher effective permeability coefficient and fraction absorbed in humans extrapolated from in situ single-pass intestinal absorption study data in rats provide an insight on the potential of proliposomes and cationic surface charge for augment in absorption across gastro intestinal barrier. To draw the conclusions, in vivo pharmacokinetic study carried out in rats indicate a threefold enhancement in the rate and extent of absorption of RXH from cationic proliposome formulation which unfurl the potential of proliposomes and role of cationic charge for improved oral delivery of RXH.

Solid lipid nanoparticles of guggul lipid as drug carrier for transdermal drug delivery

Diclofenac sodium loaded solid lipid nanoparticles (SLNs) were formulated using guggul lipid as major lipid component and analyzed for physical parameters, permeation profile, and anti-inflammatory activity. The SLNs were prepared using melt-emulsion sonication/low temperature-solidification method and characterized for physical parameters, in vitro drug release, and accelerated stability studies, and formulated into gel. Respective gels were compared with a commercial emulgel (CEG) and plain carbopol gel containing drug (CG) for ex vivo and in vivo drug permeation and anti-inflammatory activity. The SLNs were stable with optimum physical parameters. GMS nanoparticle 1 (GMN-1) and stearic acid nanoparticle 1 (SAN-1) gave the highest in vitro drug release. Guggul lipid nanoparticle gel 3 (GLNG-3) showed 104.68 times higher drug content than CEG in receptor fluid. The enhancement ratio of GLNG-3 was 39.43 with respect to CG. GLNG-3 showed almost 8.12 times higher C(max) than CEG at 4 hours. The AUC value of GLNG-3 was 15.28 times higher than the AUC of CEG. GLNG-3 showed edema inhibition up to 69.47% in the first hour. Physicochemical properties of major lipid component govern the properties of SLN. SLN made up of guggul lipid showed good physical properties with acceptable stability. Furthermore, it showed a controlled drug release profile along with a promising permeation profile.

Facilitatory effect of AC-iontophoresis of lidocaine hydrochloride on the permeability of human enamel and dentine in extracted teeth

OBJECTIVES

The objectives of the present study were to quantitatively evaluate chemical permeability through human enamel/dentine using conductometry and to clarify if alternating current (AC) iontophoresis facilitates such permeability.

MATERIALS AND METHODS

Electrical impedance of different concentrations of lidocaine hydrochloride was measured using a bipolar platinum impedance probe. A quadratic curve closely fitted to the response functions between conductance and lidocaine hydrochloride. For analysis of the passage of lidocaine hydrochloride through human enamel/dentine, eight premolars that were extracted for orthodontic treatment were sectioned at the cemento-enamel junction. The tooth crowns were held between two chambers with a double O-ring. The enamel-side chamber was filled with lidocaine hydrochloride, and the pulp-side chamber was filled with extrapure water. Two platinum plate electrodes were set at the end of each chamber to pass alternating current. A simulated interstitial pulp pressure was applied to the pulp-side chamber. The change in the concentration of lidocaine hydrochloride in the pulp-side chamber was measured every 2min using a platinum recording probe positioned at the centre of the pulp-side chamber. Passive entry without iontophoresis was used as a control.

RESULTS

The level of lidocaine hydrochloride that passed through enamel/dentine against the dentinal fluid flow increased with time. Electrical conductance (G, mho) correlated closely to the concentration (x, mmol/L) of lidocaine hydrochloride (G=2.16x(2)+0.0289x+0.000376, r(2)=0.999).

CONCLUSIONS

Lidocaine hydrochloride can pass through enamel/dentine. Conductometry showed that the level of lidocaine hydrochloride that passed through enamel/dentine was increased by AC iontophoresis.