Continuous Drug Release Research Articles

Thermosensitive Poly(DHSe/PEG/PPG Urethane)-Based Hydrogel Extended Remdesivir Application in Ophthalmic Medication.

The spread of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the coronavirus disease 2019 (COVID-19) outbreak beginning in March 2020. Currently, there is a lack of suitable dose formulations that interrupt novel coronavirus transmission via corneal and conjunctival routes. In the present study, we developed and evaluated a thermosensitive gelling system based on a selenium-containing polymer for topical ocular continuous drug release. In detail, di-(1-hydroxylundecyl) selenide (DHSe), poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) were polymerized to form poly(DHSe/PEG/PPG urethane). The polymer was used to carry poorly water-soluble remdesivir (RDV) at room temperature to form the final thermosensitive in situ gel, which exhibited a typical sol-gel transition at 35 °C. The formed polymer was further characterized by rheology, thermology, and scanning electron microscopy. In vitro release studies and in vivo retention and penetration tests indicated that the thermogel provided the prolonged release of RDV. The RDV-loaded in situ gel was proven to be non-biotoxic against human corneal epithelial cells, with good ocular tolerance and biocompatibility in rabbit eyes.

Coaxial electrospray of uniform polylactide core-shell microparticles for long-acting contraceptive

Despite its high efficacy and good patient compliance, the only long-acting injectable (LAI) contraceptive currently available in the US, depot medroxyprogesterone acetate (DMPA), is limited by significant side effects and a delayed return to fertility for up to 10 months after its intended duration of action. To overcome these limitations, we sought to develop an injectable poly(D,l-lactide) (PLA) microparticle for sustained release of contraceptive hormone, etonogestrel (ENG). A one-step technique, coaxial electrospray method was applied to prepare uniform ENG loaded core-shell structured and slow-degrading PLA microparticles (ENG-cs-MPs) to provide release control while minimizing polymer content. By adjusting voltage, polymer concentration and flow rate of the coaxial jetting solution, the prepared ENG-cs-MPs exhibited uniformly small particle size with volume mean diameter of 14.7 ± 0.5 μm and a shell thickness of 2.5 ± 0.1 μm, high drug loading of ~54%, high encapsulation efficiency of ~99%, and initial 1-day burst release of just ~10%. Long-term in vitro release of ENG was continuous for more than 3 months without change of the shell structure in 6 months. In PK studies, ENG-cs-MPs achieved a steady and continuous drug release for approximately 3 months and then quickly tapered off within 3 weeks. Hence, ENG-cs-MPs prepared by the coaxial electrospray method may be useful as a LAI contraceptive with an improved PK profile relative to DMPA.

Assessing the Molecular Interaction between Poly Lactic-co-glycolic Acid (PLGA) 50:50 and Poly Ethylene Glycol in Presence of Diethyl Phthalate Using in silico Study - A Novel Approach of Pre-Formulation Study

The efficacy of a drug relies on drug formulation and targeting. Imatinib is an anti-cancer drug identified to be effective in the treatment of cancers like myeloid leukemia and lymphoblastic leukemia, and gastrointestinal tumors. The prediction of mixing energy and identification of docking interactions and scores can help identify the most efficient drug carrier/plasticizer molecule that could exert maximum pharmaceutical efficiency. The results of a preliminary study explicitly showed the potent carrier molecule before conducting formulation studies. Hence, the present study was designed to screen the interaction energies between different combinations of Poly (lactic-co-glycolic acid) (PGLA) or Poly Ethylene Glycol (PEG) or diethyl phthalate with Imatinib using in silico computational methods. The study results suggested that the binding energy and the score obtained for docking interactions for Imatinib versus diethyl phthalate was better when compared to the other combinations. Therefore, Diethyl phthalate might be a signature candidate to act as Imatinib-carrier/plasticizer. More formulation studies are warranted further to demonstrate the desired continuous drug release and maximum efficacy with Imatinib chemotherapy.

Electrospun coaxial hyaluronan-based fiber networks for ophthalmic drug release

Abstract A micro-sized core-shell drug release device has been prepared by coaxial electrospinning based on a polylactide shell and the inner core phase made of high molecular weight hyaluronan or a cross-linked hyaluronan network. Timolol, which was inserted into the core phase, is widely used as drug for glaucoma treatment to depress the intraocular eye pressure and should be released over a longer time period from this fiber networks. Release studies of drug loaded fiber devices showed an only moderate burst release of timolol in the first days followed by a continuous longlasting drug release period over several weeks. With these findings, coaxial electrospinning represents a promising approach for the development of drug release systems with long-lasting, relatively constant drug delivery.

Skin wound healing promoted by novel curcumin-loaded micelle hydrogel.

BackgroundThe development of biomaterials with the ability to promote skin wound healing is an important topic in the field of biomedical science. In this study, a topical curcumin (Cur) gel [Cur/hyaluronic acid (HA)] was prepared by combining curcumin-loaded PCL-b-PEG-b-PCL (PECE) nanomicelles (PCEC/Cur) and HA to effectively promote skin wound healing. Continuous drug release from PCEC/Cur can provide long-term protection and treatment of skin wounds.MethodsThe study was completed in two stages. The first stage (in vitro): PCEC/Cur were prepared by thin film hydration method. The second stage (in vivo): 36 anesthetized rats were used to prepare a round full-thickness skin defect wound with a diameter of 23 mm on the dorsal side of the spine, and the rats were randomly divided into 4 groups with 9 rats in each group.ResultsThe results showed that wounds in the Cur/HA group were restored to normal after 14 days after operation, representing 96%±3% wound healing. Hematoxylin and eosin (HE) staining showed that hair follicles in the Cur/HA group were visible and that the re-epithelialization time was earlier. Masson staining showed that Cur/HA promoted the formation of collagen fibers. Immunohistochemical observation showed that angiogenesis and subsequent healing of the wound surface was enhanced in the Cur/HA group.ConclusionsThe injectable hyaluronic acid gel complex Cur/HA is a promising candidate material for a wound dressing to promote healing.

Docetaxel encapsulation in nanoscale assembly micelles of folate-PEG-docetaxel conjugates for targeted fighting against metastatic breast cancer in vitro and in vivo

Due to the high frequency and mortality of breast cancer, developing efficient targeted drug delivery systems for frightening against this malignancy is among cancer research priorities.The aim of this study was to synthesize a targeted micellar formulation of docetaxel (DTX) using DTX, folic acid (FA) and polyethylene glycol (PEG) conjugates as building blocks.In the current study, two therapeutic polymers consisting of FA-PEG-DTX and PEG-DTX conjugates were synthesized and implemented to form folate-targeted and non-targeted micelles. Dissipative particle dynamics (DPD) method was used to simulate the behavior of the nanoparticle.The anti-cancer drug, DTX was loaded in to the micelles via solvent switching method in order to increase its solubility and stability. The cytotoxicity of the targeted and non-targeted formulations was evaluated against 4T1 and CHO cell lines. In vivo therapeutic efficiency was studied using ectopic tumor model of metastatic breast cancer, 4T1, in Female BALB/c mice. The successful synthesis of therapeutic polymers, FA-PEG-DTX and PEG-DTX were confirmed implementing 1HNMR spectral analysis. The size of DTX-loaded non-targeted and targeted micelles were 176.3 ± 8.3 and 181 ± 10.1 nm with PDI of 0.23 and 0.17, respectively. Loading efficiencies of DTX in non-targeted and targeted micelles were obtained to be 85% and 82%, respectively. In vitro release study at pH = 7.4 and pH = 5.4 showed a controlled and continuous drug release for both formulations, that was faster at pH = 5.4 (100% drug release within 120 h) than at pH = 7.4 (80% drug release within 150 h). The targeted formulation showed a significant higher cytotoxicity against 4T1 breast cancer cells (high expression of folate receptor) within the range of 12.5 to 200 μg/mL in comparison with no-targeted one. However, there was no significant difference between the cytotoxicity of the targeted and non-targeted formulations against CHO cell line as low-expressed cell line. In accordance with in vitro investigation, in vivo studies verified the ideal anti-tumor efficacy of the targeted formulation compared to Taxotere and non-targeted formulation. Based on the obtained data, FA-targeted DTX-loaded nano-micelles significantly increased the therapeutic efficacy of DTX and therefore can be considered as a new potent platform for breast cancer chemotherapy.

Hyaluronic acid functionalized biodegradable mesoporous silica nanocomposites for efficient photothermal and chemotherapy in breast cancer

Chemotherapy is one of conventional treatment methods for breast cancer, but drug toxicity and side effects have severely limited its clinical applications. Photothermal therapy has emerged as a promising method that, upon combination with chemotherapy, can better treat breast cancer. In this context, a biodegradable mesoporous silica nanoparticle (bMSN NPs) system was developed for loading doxorubicin (DOX) and IR780, to be potentially applied in the treatment of breast cancer. IR780 is encapsulated in the pores of bMSN NPs by hydrophobic adsorption, while DOX is adsorbed on the surface of the bMSN NPs by hyaluronic acid electrostatically, to form the bMID NPs. Transmission electron microscopy, fluorescence spectrum and UV absorption spectrum are used to prove the successful encapsulation of IR780 and the loading of DOX. In vitro experiments have shown bMID NPs present an excellent therapeutic effect on breast cancer cells. In vivo fluorescence imaging results have indicated that bMID NPs can accumulate in tumor sites gradually and achieve in vivo long-term circulation and continuous drug release. Furthermore, bMID NPs have provided obvious antitumor effects in breast cancer mouse models, thus evolving as an efficient platform for breast cancer therapy.

A novel pellets/thermosensitive hydrogel depot with low burst release for long-term continuous drug release: Preparation, characterization, in vitro and in vivo studies

The purpose of this study was to develop a pellets/thermosensitive gel hybrid depot (Pellets-Gel), designed to provide a novel implant delivery system for long-term steady controlled release of poor soluble drug with less burst release. Pellets made from PLGA and PEG loaded with curcumin (CUR-Pellets)were fabricated via combination of solvent evaporation and extrusion spheronization technique and were characterized by the appearance, drug loading (DL), structure, thermal behavior and morphology. The sol-gel conversion properties, polymers degradation characteristics, drug release kinetics in vitro of final optimized CUR loaded Pellets-Gel (CUR-Pellets-Gel) were evaluated, in vivo pharmacokinetics study were also performed on Sprague-Dawley rats. The results demonstrated that pellets with a diameter about 1.0 mm has a high loading capacity of CUR (30% (w/w)) can be simply produced. In in vitro study, CUR-Pellets-Gel showed a low burst release (2.67%) and release completeness up to 91.83%. In the pharmacokinetics study, the in vivo burst release of CUR-Pellets-Gel was significantly decreased reflected by the AUC (0-1d)/AUC (0-td) value. CUR-Pellets-Gel showed a smoother plasma drug level with a longer drug release profile for 78 days. These results demonstrated that this hybrid depot of pellets/thermosensitive gel could be more potential application in enhanced therapeutic effects of poor soluble drugs by continuously delivering for long periods of time without burst release.

Biocompatible antibacterial nanoparticles prepared by assembling polycaprolactone-lysine-dendrimers

Novel dendritic antibacterial copolymer (PCL20-KG5) mimicking antimicrobial peptide features is synthesized by using Polycaprolactone (PCL) and BOC-Lysine(BOC)-OSu. PCL20-NH2 is designed as the core, and BOC-lysine(BOC)-OSu reacts with amino groups generation by generation to form dendritic structures. The properties and morphologies of PCL20-KG5 and their assemblies are characterized via the plate counting method, hemolytic analysis, transmission electron microscopy, dynamic light scattering, and drug release experiment. Results showed that PCL20-KG5 has excellent broad-spectrum antibacterial activity and extremely low hemolytic toxicity. It achieves antibacterial effect via membrane destruction without inducement of drug resistance. In addition, PCL20-KG5 dendrimer copolymer can self-assemble into uniform stable vesicles. Drug release experiments showed that the vesicles possess efficient drug loading capacity and are beneficial to realize continuous drug release in clinical treatment.

A Biomimetic Nano‐Engineered Platform for Functional Tissue Engineering of Cartilage Superficial Zone

Articular cartilage has limited regeneration capacity because of its acellular and avascular nature. Although tissue engineering has been shown to be life-saving, reforming cartilage zones required by the appropriate tissue functions are challenging. Herein, the need is addressed by designing and producing a nano-engineered structure mimicking the superficial zone (SZ) of articular cartilage. The substrate is based on silk with good mechanical properties in conjunction with nano-topographical and biochemical cues. Nanopillar arrays are produced on the silk surface to regulate the stem cell morphology rendering them with a flattened ellipsoidal shape that is similar to that of chondrocytes in the SZ of natural cartilage. The cell interactions are enhanced by nitrogen ion implantation and the biomolecule, kartogenin (KGN), is loaded to promote chondrogenesis of the stem cells and furthermore, a thermosensitive chitosan hydrogel is formed on the nanopatterned silk to produce rheological properties similar to those of a synovial fluid. Based on the in vitro results and mechanical properties, it is a desirable implantable smart structure mimicking the cartilage SZ with the ability of continuous drug release for cartilage regeneration.

Glycyrrhetinic Acid and TAT Peptide Modified Dual-functional Liposomes for Treatment of Hepatocellular Cancer.

Surgery remains the front-line therapeutic strategy to treat early hepatocellular carcinoma (HCC). However, the 5-year recurrence rates of HCC patients are high. 10- Hydroxycamptothecin (10-HCPT) is a known anti-HCC agent but its poor solubility and bioavailability have limited its clinical use. In this study, we developed a novel nanoliposome encapsulated 10-hydroxycamptothecin modified with glycyrrhetinic acid (GA) and TAT peptide (GA/TAT-HCPT-LP) for the treatment of HCC. Dual modified GA and TAT can enhance tumor targeting and tumor penetration. The GA/TAT-HCPT-LP NPs were synthesized using the thin-film dispersion method. GA/TAT-HCPT-LP were characterized for particle size, zeta potential and morphology. Drug release from the GA/TAT-HCPT-LP liposomes was measured by dialysis. Cell-uptake was assessed by microscopy and flow cytometry. Cell proliferation, migration and apoptosis were measured to evaluate in vitro antitumor activity of GA/TAT-HCPT-LP via CCK-8 assays, Transwell assays, and flow cytometry, respectively. The in vivo distribution of GA/TAT-HCPT-LP was evaluated in HCC animal models. Tumor- bearing mouse models were used to assess the in vivo therapeutic efficacy of GA/TAT-HCPT-LP. The mean particle size and mean zeta potential of GA/TAT-HCPT-LP were 135.55 ± 2.76 nm and -4.57 ± 0.23 mV, respectively. Transmission electron micrographs (TEM) showed that the GA/TAT-HCPT-LP had a near spherical shape and a double-membrane structure. GA/TAT-HCPT-LP led to slow and continuous drug release, and could bind to HepG2 cells more readily than other groups. Compared to control groups, treatment with GA/TAT-HCPT-LP had a significantly large effect on inhibiting cell proliferation, tumor cell migration and cell apoptosis. In vivo assays showed that GA/TATHCPT- LP selectively accumulated in tumor tissue with obvious antitumor efficacy. In conclusion, the synthesized GA/TAT-HCPT-LP could effectively target tumor cells and enhance cell penetration, highlighting its potential for hepatocellular cancer therapy.

Advances in the treatment of hepatocellular carcinoma using drug-eluting beads

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor. Although radical surgery and liver transplantation are possible cures for the disease, most patients are beyond the optimum stage for radical treatment at the time of diagnosis. Transarterial chemoembolization (TACE) is the first choice of treatment for advanced HCC. Owing to the widespread use of conventional TACE (cTACE), the problems with this treatment cannot be ignored. Drug-eluting beads (DEBs), a new type of embolization material, appear to overcome the problems of cTACE, and they have other advantages such as synchronous controlled continuous drug release after chemotherapy and embolization and low blood concentrations after treatment. This review summarizes the recent advances in the use of DEB-TACE to treat HCC.

Film-Forming Sprays for Topical Drug Delivery.

Film-forming sprays offer many advantages compared to conventional topical preparations because they can provide uniform drug distribution and dose, increased bioavailability, lower incidence of irritation, continuous drug release, and accelerated wound healing through moisture control. Film-forming sprays consist of polymers and excipients that improve the characteristics of preparations and enhance the stability of active substances. Each type of polymer and excipient will produce films with different features. Therefore, the various types of polymers and excipients and their evaluation standards need to be examined for the development of a more optimal form of film-forming spray. The selected literature included research on polymers as film-forming matrices and the application of these sprays for medical purposes or for potential medical use. This article discusses the types and concentrations of polymers and excipients, sprayer types, evaluations, and critical parameters in determining the sprayability and film characteristics. The review concludes that both natural and synthetic polymers that have in situ film or viscoelastic properties can be used to optimise topical drug delivery.

Preparation and Characterization of PVA-Co-PE Drug-Loaded Nanofiber Membrane by Electrospinning Technology.

A new transdermal drug delivery system of nanofiber membrane with good biocompatibility and high drug loading was developed by electrospinning technology in this study. Using vinyl alcohol-co-ethylene (PVA-co-PE) polymer as a spinning matrix and non-steroidal anti-inflammatory drug (NSAID) sulindac (SUL) as a model drug, the SUL@PVA-co-PE nanofiber membrane was prepared and characterized systematically. The morphology, molecular vibrational transitions, thermogravimetric attributes, and in vitro drug release and transdermal characteristics of drug-loaded nanofiber membranes were analyzed. The results indicated that the surface of PVA-co-PE nanofibers was uniform and smooth with the diameter ranged from 461 to 696nm. Notably in vitro simulation experiments demonstrated that SUL@PVA-co-PE nanofiber membrane could provide a continuous drug release to reach the effective concentration of the drug, and exhibited significantly higher cumulative drug permeability compared to commercially available patches, Taken together, PVA-co-PE nanofiber membranes exhibited the characteristics of high drug loading and stability, and represented the potential to be utilized as a new transdermal drug delivery carrier with pronounced development prospect.

ROLE OF MICROSPHERES IN NOVEL DRUG DELIVERY SYSTEMS: PREPARATION METHODS AND APPLICATIONS

Microsphere based drug delivery system has gained substantial attention in the modern era. Microspheres are normally free-flowing powders that can be made with both natural and synthetic polymers. The sizes of the microspheres ranges from 1 to 1000 µm. Microspheres are matrix systems in which the drug is uniformly dispersed, dissolved or suspended. Microspheres contain solid or liquid drug dissolved or dispersed in a matrix system. The current review provides an inclusive outline of up to date and novel developments on formations of microspheres which have been reported to increase bioavailability, improves stability, enhances biological half-life and reduces the toxicity of the drug. Microsphere provides efficient delivery of various proteins and peptide molecules. There are different types of microspheres such as bio adhesive microsphere, magnetic microsphere, floating microsphere, and polymeric microspheres. Diverse kinds of methods are used in the formulation of microsphere e. g. Simple emulsion-based method, Double emulsion-based method, Interfacial deposition technique, Interfacial polymerization technique, Phase separation method, and Spray drying. Microspheres deliver the drug in a controlled manner through different routes like oral, topical, naso-pulmonary and gene therapy. The Polymeric based microspheres are model carriers for numerous controlled delivery applications owing to their capacity to encapsulate a diversity of drugs, bio-compatibility, high bio-availability and continuous drug release character. Therefore, by developing newer techniques, it can give more therapeutic effects and improves the safety of drugs. The formation of microspheres has been reported to increase bioavailability, improves stability, enhances biological half-life and reduces the toxicity of the drug.

Construction of Biocompatible Dual-Drug Loaded Complicated Nanoparticles for in vivo Improvement of Synergistic Chemotherapy in Esophageal Cancer

Combination chemotherapy is a routine treatment for esophageal cancer, but some shortcomings, such as drug toxicity and side effects, greatly limit the clinical application of combination therapy. To overcome these shortcomings, we have developed a mesoporous silica nanoparticle system that was used to load doxorubicin and β-elemene. β-elemene was encapsulated in the pore of mesoporous silica nanoparticle and doxorubicin was electrostatically adsorbed on the surface of mesoporous silica nanoparticle by hyaluronic acid to construct dual drugs synergistic nanoparticles (bMED NPs, ~77.15 nm). In vitro studies demonstrated that bMED NPs had a good treatment effect in esophageal cancer cell lines. In vivo fluorescence imaging results demonstrated that bMED NPs could accumulate in tumor sites and achieve in vivo long-term circulation and continuous drug release. In addition, bMED NPs exhibited significant antitumor effects in the esophageal cancer mouse model, which may provide a great platform for esophageal cancer chemotherapy.

Biodistribution of etoposide via intratumoral chemotherapy with etoposide-loaded implants

Etoposide (VP16) is the traditional antitumor agent which has been widely used in a variety of cancers. However, intravenous administration of VP16 was limited in clinical application because of its low aqueous solubility, poor bioavailability and dose-limiting adverse effects. Local chemotherapy with VP16-loaded drug delivery systems could provide a continuous release of drug at the target site, while minimizing the systemic toxicity. In this study, we prepared the poly-l-lactic acid (PLLA) based VP16-loaded implants (VP16 implants) by the direct compression method. The VP16 implants were characterized with regards to drug content, micromorphology, drug release profiles, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) analyses. Furthermore, the biodistribution of VP16 via intratumoral chemotherapy with VP16 implants was investigated using the murine Lewis lung carcinoma model. Our results showed that VP16 dispersed homogenously in the polymeric matrix. Both in vitro and in vivo drug release profiles of the implants were characterized by high initial burst release followed by sustained release of VP16. The VP16 implants showed good compatibility between VP16 and the excipients. Intratumoral chemotherapy with VP16 implants resulted in significantly higher concentration and longer duration of VP16 in tumor tissues compared with single intraperitoneal injection of VP16 solution. Moreover, we found the low level of VP16 in plasma and normal organ tissues. These results suggested that intratumoral chemotherapy with VP16 implants enabled high drug concentration at the target site and has the potential to be used as a novel method to treat cancer.

Hypoxic targeting and activating TH-302 loaded transcatheter arterial embolization microsphere

The tumor-derived and transcatheter arterial chemoembolization (TACE) induced hypoxia microenvironment is closely related to the poor prognosis of hepatocellular carcinoma (HCC). In this study, hypoxia-activated prodrug TH-302 loaded poly(lactic-co-glycolic acid) (PLGA)-based TACE microspheres were prepared to treat HCC through localized and sustained drug delivery. TH-302 microspheres with three different sizes were fabricated by an oil-in-water emulsion solvent evaporation method and characterized by scanning electron microscopy (SEM), infrared spectra (IR), X-ray diffractometer (XRD), and drug release profiles. The in vitro antitumor potential was firstly evaluated in an HepG2 cell model under normoxic and hypoxic conditions. Then, a VX-2 tumor-bearing rabbit model was established and performed TACE to investigate the in vivo drug tissue distribution and antitumor efficiency of TH-302 microspheres. Blood routine examination and histopathological examinations were also conducted to evaluate the safety of TH-302 microspheres. TH-302 microspheres with particle size 75–100 μm, 100–200 μm, and 200–300 μm were prepared and characterized by sphere morphology and sustained drug release up to 360 h. Compared with TH-302, the microspheres exhibited higher cytotoxicity, cell apoptosis, and cell cycle S phase retardation in HepG2 cells under hypoxic conditions. The microspheres also displayed continuous drug release in the liver tissue and better anti-tumor efficiency compared with TH-302 injection and lipiodol. Meanwhile, no serious toxicity appeared in the duration of treatment. Therefore, TH-302 microspheres showed to be feasible and effective for TACE and hold promise in the clinical for HCC chemoembolization therapy.

Recent Trends in Chronopharmaceutics, Pulsatile Drug Delivery System

Pulsatile Drug Delivery Systems (PDDS) are getting considerable interest in delivering a drug at the correct position, at the correct time, and in the correct quantity, thus offering temporal, spatial, and intelligent delivery with improving patient compliance. These systems are
 
 intended to meet body's biological rhythm. Here, the delivery of drugs is assisted by the rhythm of disease. The main reason for the using pulsatile drug release is when the continuous drug release is not required. A PDDS must be designed in such a way that after the lag time a complete and fast release of drugs is achieved. The article deals with various systems such as osmotic system, capsular system, single and multi-unit system based on the utilization of erodible or soluble polymer coating and using of rupturable membrane. These systems are favorable to drugs with chronopharmacological behaviors such as drugs used to treat rheumatoid arthritis, ankylosing spondylitis, and osteoarthritis. The current review paper focus on the causes for pulsatile drug delivery system design, types of illness requiring pulsatile release, classification, benefits, and restriction of this drug delivery system.

Preparation and in Vitro Evaluation of Soya Lecithin Based Nano Transfersomal Dispersion for Loxoprofen Sodium

This work involves investigation and evaluation of the factors that affect the preparation and release of the model class I drug (loxoprofen sodium) to optimize the efficiency of its prepared nano transfersomal dispersion to give rapid onset of action (burst effect) within the
 
 first 2 hours that can continue for further four hours. The work involved preparation of twenty formulas of transfersomal dispersion by thin film method which were nano-sized by probe sonication and characterized morphologically by Transmission electronic microscopic (TEM), zeta potential, particle size, polydispersity index (pdI), pH, physical appearance, entrapment efficiency, viscosity, transmittance and in vitro drug release. The selected nano transfersomal formula (SF16) showed pH (7.2), particle size (393 nm), pdI (0.259), zeta potential (-25), entrapment efficiency (91%) and gave a 73% drug release within the first 2 hours of the in vitro test and continued until it gave 86.35% drug release after 4 h. This work succeeded in preparing optimized tansfersomal dispersion for loxoprofen sodium using different soya lecithin / edge activator percent and different types of edge activator. The optimum formula gave an immediate release of the model drug (loxoprofen sodium) and it was ready to be incorporated in any suitable dosage form to give continuous drug release.