Paclitaxel-Loaded Colloidal Silica and TPGS-Based Solid Self-Emulsifying System Interferes Akt/mTOR Pathway in MDA-MB-231 and Demonstrates Anti-tumor Effect in Syngeneic Mammary Tumors

LC-MS/MS method for simultaneous Doxorubicin and Baicalein estimation: formulation and pharmacokinetic applications

Aim & objective: Combinatorial delivery of Doxorubicin (DOX) and Baicalein (BAC) has a potential to improve breast cancer treatment by mitigating the cardiotoxicity induced by DOX. The nanoformulation has been optimized and subjected to pharmacokinetic studies using LC-MS/MS.Materials & methods: Nanoformulation bearing DOX and BAC was optimized using quality by design approach and method validation was done following USFDA guidelines.Results: The particle size, PDI and zeta potential of developed nanoformulation were 162.56 ± 2.21 nm, 0.102 ± 0.03 and -16.5 ± 1.21 mV, respectively. DOX-BAC-SNEDDs had a higher AUC0-t values of 6128.84 ± 68.71 and 5896.62 ± 99.31 ng/mL/h as compared with DOX-BAC suspension.Conclusion: These findings hold promise for advancing breast cancer treatment and facilitating therapeutic drug monitoring.

Evaluation of the pharmacokinetics, chylomicron inhibition, and toxicity of colchicine in rats given low doses

Colchicine (COL) is known for its ability to inhibit the formation of intestinal chylomicrons and has been utilized as a non-surgical tool to explore drug absorption via the intestinal lymphatics. However, there is limited understanding of its pharmacokinetics and its relationship to effect and toxicity with the doses used. This study aimed to provide comprehensive COL pharmacokinetic data and correlate it with the lymphatic-blocking and toxicological effects of low-doses. Male Sprague-Dawley rats with jugular-vein cannulation (JVC) received 0.1 to 0.5 mg/kg COL via oral, 0.25 mg/kg intraperitoneal, and 0.1 mg/kg intravenous routes, followed by blood and urine sampling for LC-MS/MS analysis. Effects on lipid absorption were assessed in another eight JVC rats receiving peanut oil with and without COL, followed by blood pharmacokinetic and plasma biochemistry analysis. The results revealed that COL exhibited moderate extraction ratio and high volume of distribution, with low oral bioavailability (<8%). About 20 % was recovered in the urine after parenteral dosing. Modest but significant reductions in cholesterol absorption was observed after oral doses of 0.5 mg/kg, accompanied by signs of inflammation and increased liver enzymes persisting for a week. The effect of COL on triglycerides formation was not significant. Despite its use as a non-surgical tool in rats to investigate drug absorption via the lymphatic pathway, COL demonstrated increased levels of liver function enzymes, emphasizing the need for caution and dose optimization in its utilization.

Understanding lymphatic drug delivery through chylomicron blockade: A retrospective and prospective analysis

Scientists have developed and employed various models to investigate intestinal lymphatic uptake. One approach involves using specific blocking agents to influence the chylomicron-mediated lymphatic absorption of drugs. Currently utilized models include pluronic L-81, puromycin, vinca alkaloids, colchicine, and cycloheximide. This review offers a thorough analysis of the diverse models utilized, evaluating existing reports while delineating the gaps in current research. It also explores pharmacokinetic related aspects of intestinal lymphatic uptake pathway and its blockage through the discussed models. Pluronic L-81 has a reversible effect, minimal toxicity, and unique mode of action. Yet, it lacks clinical reports on chylomicron pathway blockage, likely due to low concentrations used. Puromycin and vinca alkaloids, though documented for toxicity, lack information on their application in drug intestinal lymphatic uptake. Other vinca alkaloids show promise in affecting triglyceride profiles and represent possible agents to test as blockers. Colchicine and cycloheximide, widely used in pharmaceutical development, have demonstrated efficacy, with cycloheximide preferred for lower toxicity. However, further investigation into effective and toxic doses of colchicine in humans is needed to understand its clinical impact. The review additionally followed the complete journey of oral lymphatic targeting drugs from intake to excretion, provided a pharmacokinetic equation considering the intestinal lymphatic pathway for assessing bioavailability. Moreover, the possible application of urinary data as a non-invasive way to measure the uptake of drugs through intestinal lymphatics was illustrated, and the likelihood of drug interactions when specific blockers are employed in human subjects was underscored.

Synchronized Codelivery of Combination Chemotherapies Intratumorally Using a Lipidic Lyotropic Liquid Crystal System

In this work, an injectable in situ depot-forming lipidic lyotropic liquid crystal (L3C) system is developed to codeliver a precisely synchronized combination of chemotherapeutics intratumorally. The developed L3C system is composed of amphiphilic lipids and surfactants, including monoolein, phosphatidylcholine, tocopherol acetate, and d-α-tocopherol polyethylene glycol 1000 succinate. Owing to its amphiphilic nature, the developed formulation can coaccommodate both hydrophobic and hydrophilic chemotherapeutic moieties simultaneously. The study presents a proof of concept by designing a combination chemotherapy regimen in vitro and demonstrating its in vivo translation using doxorubicin and paclitaxel as model hydrophilic and hydrophobic drug moieties, respectively. The synchronized combination of the two chemotherapeutics with maximum synergistic activity was identified, coloaded in the developed L3C system at predefined stoichiometric ratios, and evaluated for antitumor efficacy in the 4T1 breast tumor model in BALB/c mice. The drug-loaded L3C formulation is a low-viscosity injectable fluid with a lamellar phase that transforms into a hexagonal mesophase depot system upon intratumoral injection. The drug-loaded depot system locally provides sustained intratumoral delivery of the chemotherapeutics combination at their precisely synchronized ratio for over a period of one month. Results demonstrate that the exposure of the tumor to the precisely synchronized intratumoral chemotherapeutics combination via the developed L3C system resulted in significantly higher antitumor activity and reduced cardiotoxicity compared to the unsynchronized combination chemotherapy or the synchronized but uncoordinated drug delivery administered by a conventional intravenous route. These findings demonstrate the potential of the developed L3C system for achieving synchronized codelivery of the chemotherapeutics combination intratumorally and improving the efficacy of combination chemotherapy.

Enhanced oral bioavailability of levormeloxifene and raloxifene by nanoemulsion: simultaneous bioanalysis using liquid chromatography-tandem mass spectrometry

Aim & objective: Levormeloxifene (L-ORM) and raloxifene (RAL) are selective estrogen receptor modulators used in the treatment of postmenopausal osteoporosis and breast cancer. Here, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous estimation of both drugs. Materials & methods: A quality-by-design (QbD) approach was used for the optimization of the nanoemulsion, and US FDA guidelines were followed for method validation. Results: Multiple reaction monitoring transitions were used for L-ORM (459.05→98.50), RAL (475.00→112.02) and internal standard (180.10→110.2). Analytes were resolved in a C18 column with 80:20 v/v% acetonitrile (ACN), 0.1% formic acid in triple-distilled water as a mobile phase. The developed method was linear over a concentration range of 1-600 ng/ml. Pharmacokinetic results of free L-ORM-RAL and the L-ORM-RAL nanoemulsion showed Cmax of free L-ORM - 70.65 ± 16.64, free RAL 13.53 ± 2.72, L-ORM nanoemulsion 65.07 ± 14.0 and RAL-nanoemulsion 59.27 ± 17.44 ng/ml. Conclusion: Future findings will contribute to the treatment of postmenopausal osteoporosis and breast cancer using L-ORM and RAL.

Smart Targeted Delivery Systems for Enhancing Antitumor Therapy of Active Ingredients in Traditional Chinese Medicine

As a therapeutic tool inherited for thousands of years, traditional Chinese medicine (TCM) exhibits superiority in tumor therapy. The antitumor active components of TCM not only have multi-target treatment modes but can also synergistically interfere with tumor growth compared to traditional chemotherapeutics. However, most antitumor active components of TCM have the characteristics of poor solubility, high toxicity, and side effects, which are often limited in clinical application. In recent years, delivering the antitumor active components of TCM by nanosystems has been a promising field. The advantages of nano-delivery systems include improved water solubility, targeting efficiency, enhanced stability in vivo, and controlled release drugs, which can achieve higher drug-delivery efficiency and bioavailability. According to the method of drug loading on nanocarriers, nano-delivery systems can be categorized into two types, including physically encapsulated nanoplatforms and chemically coupled drug-delivery platforms. In this review, two nano-delivery approaches are considered, namely physical encapsulation and chemical coupling, both commonly used to deliver antitumor active components of TCM, and we summarized the advantages and limitations of different types of nano-delivery systems. Meanwhile, the clinical applications and potential toxicity of nano-delivery systems and the future development and challenges of these nano-delivery systems are also discussed, aiming to lay the foundation for the development and practical application of nano-delivery systems of TCM in clinical settings.

Enhanced apoptosis and mitochondrial cell death by paclitaxel-loaded TPP-TPGS1000-functionalized nanoemulsion

Background: The present research was designed to develop a nanoemulsion (NE) of triphenylphosphine-D-α-tocopheryl-polyethylene glycol succinate (TPP-TPGS₁₀₀₀) and paclitaxel (PTX) to effectively deliver PTX to improve breast cancer therapy. Materials & methods: A quality-by-design approach was applied for optimization and in vitro and in vivo characterization were performed. Results: The TPP-TPGS₁₀₀₀-PTX-NE enhanced cellular uptake, mitochondrial membrane depolarization and G₂M cell cycle arrest compared with free-PTX treatment. In addition, pharmacokinetics, biodistribution and in vivo live imaging studies in tumor-bearing mice showed that TPP-TPGS₁₀₀₀-PTX-NE had superior performance compared with free-PTX treatment. Histological and survival investigations ascertained the nontoxicity of the nanoformulation, suggesting new opportunities and potential to treat breast cancer. Conclusion: TPP-TPGS₁₀₀₀-PTX-NE improved the efficacy of breast cancer treatment by enhancing its effectiveness and decreasing drug toxicity.

HPLC method for simultaneous estimation of paclitaxel and baicalein: pharmaceutical and pharmacokinetic applications

Aim: A novel HPLC method was developed and validated for the simultaneous estimation of paclitaxel (PTX) and baicalein (BAC). Materials & methods: The analytes were resolved in a C18 column using the aqueous solution of formic acid (0.10% v/v) and MeOH (30:70 v/v). Results: The developed method was found to be linear over the concentration ranges 0.039-10 μg/ml and 0.019-10 μg/ml for PTX and BAC, respectively. The lower limits of quantification obtained were 0.042 μg/ml and 0.361 μg/ml for PTX and BAC, respectively. Conclusion: The developed method was found to be precise and accurate as per the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines, for simultaneous estimation of PTX and BAC, having an application in formulation development and bioanalytical studies.

Multifunctional Role of Silica in Pharmaceutical Formulations

Due to the high surface area, adjustable surface and pore structures, and excellent biocompatibility, nano- and micro-sized silica have certainly attracted the attention of many researchers in the medical fields. This review focuses on the multifunctional roles of silica in different pharmaceutical formulations including solid preparations, liquid drugs, and advanced drug delivery systems. For traditional solid preparations, it can improve compactibility and flowability, promote disintegration, adjust hygroscopicity, and prevent excessive adhesion. As for liquid drugs and preparations, like volatile oil, ethers, vitamins, and self-emulsifying drug delivery systems, silica with adjustable pore structures is a good adsorbent for solidification. Also, silica with various particle sizes, surface characteristics, pore structure, and surface modification controlled by different synthesis methods has gained wide attention owing to its unparalleled advantages for drug delivery and disease diagnosis. We also collate the latest pharmaceutical applications of silica sorted out by formulations. Finally, we point out the thorny issues for application and survey future trends pertaining to silica in an effort to provide a comprehensive overview of its future development in the medical fields. Graphical Abstract.

Validated HPLC-UV Method for Simultaneous Estimation of Paclitaxel and Doxorubicin Employing Ion Pair Chromatography: Application in Formulation Development and Pharmacokinetic Studies

Though paclitaxel (PTX) and doxorubicin (DOX) are amongst the most widely used and investigated drug pair for combination chemotherapy but surprisingly, not a single validated HPLC-UV method is available to analyze PTX and DOX simultaneously. So, herein a HPLC-UV method is developed and validated for the same, filling an indispensable gap in the literature. As these two moieties have characteristically different polarities, resolving them under the common chromatographic conditions is a challenging task. Herein, the principle of ion pair chromatography is utilized to resolve these two moieties on a C18 column employing an isocratic mobile phase comprised of acetonitrile and octane sulfonic acid buffer (67 : 37) and detected simultaneously at 231 nm using a UV detector only. The retention time is 4.4 and 7.2 min for PTX and DOX, respectively, with a total analysis time of less than 10 minutes, suitable for the formulation development and research, while LOQ is less than 0.066 μg/ml for both the drugs, suitable for the therapeutic drug monitoring at preclinical and clinical research setup. To substantiate the applicability of the developed method, a nanoformulation coloaded with PTX and DOX was designed and analyzed using the developed protocol. The method is also applied successfully to study the plasma kinetic profile of both the moieties simultaneously in Balb/c mice. Further, the method is validated as per the ICH guidelines fulfilling the unmet need of a validated analytical tool to simultaneously estimate PTX and DOX. Moreover, the results suggest that the principal of common ion chromatography demonstrated here can also be applied further for the simultaneous chromatographic separation of other polar and nonpolar moieties too. Consequently, the reported method surely will advance the toolset required for the precision-based combination chemotherapy.

An Injectable In Situ Depot-Forming Lipidic Lyotropic Liquid Crystal System for Localized Intratumoral Drug Delivery

To address the need for localized chemotherapy against unresectable solid tumors, an injectable in situ depot-forming lipidic lyotropic liquid crystal system (L3CS) is explored that can provide spatiotemporal control over drug delivery. Although liquid crystals have been studied extensively before but their application as an injectable intratumoral depot system for locoregional chemotherapy has not been explored yet. The developed L3CS in the present study is a low-viscosity injectable fluid having a lamellar phase, which transforms into a hexagonal mesophase depot system on subcutaneous or intratumoral injection. The transformed depot system can be preprogrammed to provide tailored drug release intratumorally, over a period of one week to one month. To establish the efficacy of the developed L3CS, doxorubicin is used as a model drug. The drug release mechanism is studied in detail both in vitro and in vivo, and the efficacy of the developed system is investigated in the murine 4T1 tumor model. The direct intratumoral injection of the L3CS provided localized delivery of doxorubicin inside the tumor and restricted its access within the tumor only for a sustained period of time. This led to an over 10-fold reduction in tumor burden, reduced cardiotoxicity, and a significant increase in the median survival rate, compared to the control group. The developed L3CS thus provides an efficient strategy for localized chemotherapy against unresectable solid tumors with a great degree of spatial and temporal control over drug delivery.

Solid self emulsifying drug delivery system: Superior mode for oral delivery of hydrophobic cargos

A significant proportion of recently approved drug molecules possess poor aqueous solubility which further restrains their desired bioavailability. Poor aqueous solubility of these drugs poses significant hurdles in development of novel drug delivery systems and achieving target response. Self-emulsifying drug delivery systems (SEDDS) emerged as an insightful approach for delivering highly hydrophobic entities to enhance their bioavailability. Conventional SEDDS were developed in a liquid form which owned numerous shortcomings like low stability and drug loading efficiency, fewer choices of dosage forms and irreversible precipitation of drug or excipients. To address these curbs solid-SEDDS (S-SEDDS) was introduced as an efficient strategy that combined advantages of solid dosage forms such as increased stability, portability and patient compliance along with substantial improvement in the bioavailability. S-SEDDS are isotropic mixtures of oil, surfactant, solvent and co-solvents generated by solidification of liquid or semisolid self-emulsifying ingredients onto powders. The present review highlights components of S-SEDDS, their peculiarities to be considered while designing solid dosage forms and various methods of fabrication. Lastly, key challenges faced during development, applications and future directions for the research in this area are thoroughly summarized.