Quasi-emulsion Solvent Diffusion Method Research Articles

Formulation and evaluation of Dorzolamide hydrochloride microsponges loaded in situ gel for ocular administration

Due to the unique structure of the eye, which inhibits the entry of drug molecules into the desired site, the ophthalmic delivery of the drug has been one of the most challenging tasks for a pharmaceutical scientist. For this reason, in this investigation a novel microsponge for an anti-glaucoma drug, Dorzolamide hydrochloride, was formulated as in situ gel for ocular administration with an aim to improve its therapeutic efficacy and reduce the systemic adverse effects. The microsponges were prepared by the quasi emulsion solvent diffusion method and was incorporated into 20% pluronic F-127 which led to consistent in situ gel at 35°C. They were evaluated for physicochemical properties like pH, gelling capacity, gelation time, rheological properties and release profile and ocular irritancy test. The prepared Dorzolamide hydrochloride microsponges showed high entrapment efficiency of 85% and mean particle size of 2 μm with polydispersity index (PDI) of 0.77 which are ideal for ocular delivery. These microsponges is formulated into in situ gel which showed higher therapeutic efficacy compared to free drug in gel. It was found to be non-irritant to the rabbit’s eye. These results confirms that Dorzolamide hydrochloride microsponges in situ gels have promising features, benefits and advantages for a novel ophthalmic drug delivery to treat glaucoma.

Development of 4-phenylbutyric acid microsponge gel formulations for the treatment of lewisite-mediated skin injury.

Lewisite, a chemical warfare agent, causes skin blisters, erythema, edema, and inflammation, requiring mitigation strategies in case of accidental or deliberate exposure. 4-phenyl butyric acid (4-PBA), a chemical chaperone, reduces endoplasmic reticulum stress and skin inflammation. The study aimed to encapsulate 4-PBA in microsponges for effective, sustained delivery against lewisite injury. Porous microsponges in a topical gel would potentially sustain delivery and improve residence time on the skin. Microsponges were developed using the quasi-emulsion solvent diffusion method with Eudragit RS100. Optimized formulation showed 10.58%w/w drug loading was incorporated in a carboxymethylcellulose (CMC) and Carbopol gel for in vitro release and permeation testing using dermatomed human skin. A sustained release was obtained from all vehicles in the release study, and IVPT results showed that compared to the control (41.52 ± 2.54µg/sq.cm), a sustained permeation profile with a reduced delivery was observed for microsponges in PBS (14.16 ± 1.23µg/sq.cm) along with Carbopol 980 gel (12.55 ± 1.41µg/sq.cm), and CMC gel (10.09 ± 1.23µg/sq.cm) at 24h. Optimized formulation showed significant protection against lewisite surrogate phenyl arsine oxide (PAO) challenged skin injury in Ptch1+/-/SKH-1 hairless mice at gross and molecular levels. A reduction in Draize score by 29%, a reduction in skin bifold thickness by 8%, a significant reduction in levels of IL-1β, IL6, and GM-CSF by 54%, 30%, and 55%, respectively, and a reduction in apoptosis by 31% was observed. Thus, the translational feasibility of 4-PBA microsponges for effective, sustained delivery against lewisite skin injury is demonstrated.

Preparation, characterisation and in vitro anti-inflammatory activity of Baicalin microsponges

Baicalin, a flavonoid extracted from traditional Chinese medicine, Scutellaria baicalensis has significant anti-inflammatory effects. Microsponges are drug delivery systems that improve drug stability and slow the release rate. The combination of baicalin and the microsponges produced a new and stable system for its delivery, resulting in a novel formulation of baicalin. Baicalin microsponges (BM) were prepared using the quasi-emulsion solvent diffusion method. Effects of the mass ratio of the polymer (ethylcellulose) to baicalin, the concentration of the emulsifier polyvinyl alcohol (PVA), the stirring speed on the encapsulation efficiency (EE), and yield of the microsponges were investigated by combining the one-factor test and Box-Behnken design (BBD). The preparation process was standardised using 2.61:1 mass ratio of ethyl cellulose to baicalin, 2.17% concentration of PVA, with stirring at 794 rpm. Optimised BM formulations were evaluated for the parameters of EE (54.06 ± 3.02)% and yield of (70.37 ± 2.41)%, transmission electron microscopy (TEM), and in vitro cell evaluation. Results of the in vitro anti-inflammatory assay showed that baicalin microsponges-pretreated-lipopolysaccharide (LPS)-induced RAW264.7, mouse macrophages showed reduced inflammatory response, similar to that seen in baicalin-treated macrophages.

Formulation and Evaluation of Terbinafine Hydro-chloride Loaded Microsponges Gel

Background: Microsponges are porous, polymeric microspheres employed for sustained topical treatment. They may modify the release pattern, lessen adverse effects, and improve stability. Terbinafine HCL is a fungicidal allylamine derivative with a wide range of antifungal activity. It is used to treat various skin disorders like ringworm, athlete’s foot, and jock itch. Objective: The aim of the current study focuses on the development of terbinafine HCL microsponges that will release the drug in a sustained pattern to prevent side effects and then put those microsponges into a gel. Method: The quasi-emulsion solvent diffusion method was employed to develop Microsponges by using various drug: polymer ratios. Result: The results of the FTIR spectra showed that there was an absence of interaction between Terbinafine HCL and the excipients. Based on the evaluation parameter, it was found that batch MS3 showed the highest entrapment efficiency of 86.32%. Polymer EC showed better results. Microsponges and Microsponges gel showed sustained release of drug till 8 and 10 hours, respectively. The gels were shown to be stable throughout a wide temperature range, according to the stability studies. Conclusion: It was concluded that the Microsponges release the drug in a stained manner. The production process for microsponge technology has the potential to improve patient compliance with terbinafine hydrochloride microsponge gel.

DEVELOPMENT OF ACECLOFENAC LOADED MICROSPONGE GELS: A STATISTICAL QUALITY BY DESIGN (QBD) APPROACH TOWARDS OPTIMIZATION AND EVALUATION

Objective: The current research aims to deliver Aceclofenac in a controlled manner through a microsponges-loaded drug delivery system for the treatment of inflammation. Methods: The formulations were prepared by the Quasi-emulsion solvent diffusion method and characterized for particle size and drug entrapment efficiency. For the optimization of the formulation through the Quality by Design (QbD) approach, Quality target product profiles (QTPP) were set up considering various key factors that affect the quality of the formulation. Further optimization of the important factors in relation to the major Critical Quality Attributes (CQAs) was conducted by applying full factorial design using the Design of Expert Software (11.0 software, Stat-Ease, Inc., USA). The optimized formulation was incorporated into the gel, and characterized for morphological analysis by Scanning Electron Microscopy (SEM), drug content, and ex-vivo permeation studies (DD solver, Version 2.0). Results: It was found that process parameters such as drug-to-polymer ratio, the volume of the internal phase, and concentration of the emulsifier and polyvinyl alcohol (PVA), played a crucial role in improving the drug entrapment efficiency and particle size. On the other hand, stirring time did not significantly affect the particle size. Through Design of Expert (DOE) analysis, a PVA concentration of 0.641 mg/ml and an internal phase volume of 12.5 ml were identified to be the ideal concentrations to obtain the optimized microspongal gel formulation (MS4). Characterization studies were carried out on MS4, which displayed a drug encapsulation of 94%, with a Cmax of 81.62 mg/ml, and a Tmax of 12 h. Stability studies carried out as per the International Conference of Harmonization (ICH) guidelines confirmed no noticeable change in physical appearance and drug content. Conclusion: Overall, this study focused on optimizing the formulation of microsponges for efficient dermal drug delivery, considering various critical variables and process parameters. The resulting optimized formulation demonstrated promising drug release and potential for the effective management of inflammation disorders.

Formulation and Evaluation of Topical Microsponge Based Gel of Clotrimazole

The study's overarching goal is to develop a novel medication delivery method based on microsponge gel containing clotrimazole. Clotrimazole is poorly absorbed from the gastrointestinal tract (GIT), has a short half-life of only 2 h, & is metabolized into inert molecules by the liver. Therefore, clotrimazole's drug delivery method must be modified for topical application. Microsponge delivery is a novel approach to sustained drug release. Microsponges were made with a polymer solution of Eudragit RS 100 in dichloromethane (DCM) and ethanol (1:1) using a quasi-emulsion solvent diffusion technique. A number of metrics, including production yield, entrapment efficiency, particle size measurement, and in vitro drug release studies, were used to each microsponge formulation. For topical administration, the optimized microsponge formulation F6 was transformed into a gel formulation. Prepared gel was compared to a commercially available formulation based on physical factors such as pH, viscosity, spreadability, drug content, and an in vitro diffusion investigation. Most of the formulations were discrete and spherical in shape, indicating a satisfactory production yield, suggesting quasi-emulsion solvent diffusion method is a promising methodology for the fabrication of microsponge. Clotrimazole was released steadily over the course of 12 hours from the microsponge gel formulation MGI (F6). Therefore, the medicine in the form of a microsponge can reduce the risk of adverse effects and increase patient compliance by avoiding skin contact.

Formulation Of Benzoyl Peroxide Microsponge-Based Transdermal Gel For Acne Infection And Its Evaluation.

Benzoyl peroxide is a peroxide with antibacterial, irritating, keratolytic, comedolytic, and anti-inflammatory properties. When benzoyl peroxide is applied topically, it breaks down and releases oxygen, which kills the germs of Propionibacterium acnes. Benzoyl peroxide's irritating impact causes an increase in epithelial cell turnover, which causes the skin to peel and aids in the healing of comedones. Treatment for acne vulgaris involves the use of benzoyl peroxide. The research is aimed at studying the formulation of Microsponge gel preparation of benzoyl peroxide by using Carbopol 934 as a gelling agent and evaluation of microsponge gel formulation for its physicochemical properties. Microsponges of Anti-acne agent benzoyl peroxide drug were prepared by quasi-emulsion method, and in-vitro drug release using a suitable membrane model using a simple diffusion cell. Prior to drying, the microsponge was filtered and rinsed using distilled water. Formulation containing benzoyl peroxide and Eudragit RS100 with a ratio of 1:4 showed a high 87.5% drug content and 78.20 % yield. The drug content of the microsponge gel was found to be 84%. Microbiological study on S. aureus was conducted by the cylinder cup method and found good results. The in-vitro diffusion of microsponge formulations was sustained for 8 hours. The drug release rate for Eudragit RS-100 was reported to be 88.87% after 8 hours based on the polymer: drug ratio (4:1). The quasi-emulsion solvent diffusion method was used to successfully prepare benzoyl peroxide microsponges using Eudragit RS100, Ethyl Cellulose, and HPMC K4M as polymers. The formulations with the highest medication concentration were made with the porous polymer Eudragit RS100.

Sustained release of salicylic acid from ethyl cellulose microspheres fabricated using quasi-emulsion solvent diffusion method

Delivery of drugs using micro-sized particles is an efficient tool. Using ethyl cellulose (EC) as a polymer and the quasi-emulsion solvent diffusion (QESD) method paves the way for the utilization of a cost-effective polymer and an efficient fabrication method. Poly(vinyl alcohol) in water was used as an external phase while EC and Salicylic acid (SA) were dissolved in dichloromethane as an internal phase. SA is known to inhibit prostaglandins and have an anti-inflammatory effect. Furthermore, it inhibits the formation of bacterial biofilm on surfaces. Microparticles of several variations were successfully fabricated using the QESD method in an efficient time frame. These microparticles ranged in size from 5 to 40 μm for these formulations. Characterization results substantiated the selection of materials used for fabrication. Cytotoxicity showed that these fabrications were biocompatible and did not inhibit cell proliferation. In vitro drug release studies showed that the fabricated EC microparticles were able to sustainably release the drugs contained within them over a 96-h time period, with most of the drug being released after 48 h. This release never exceeded 63% of the total drug content. PEG addition in the fabrication process of formulation ECPSA eliminated burst release, resulting in a sustained release pattern over 48 h, reaching saturation by day 5. While entrapment was dependent on the polymer content, increasing drug content did not significantly affect drug release. Behavioral studies evaluated the microspheres, revealing different kinetic models, including Higuchi in ECSA2 and Korsmeyer-Peppas in ECSA3, ECSA5, ECSA6, and ECPSA, with varying diffusion mechanisms. Future fabrications can be made to increase the porousness of the spheres to increase drug release from the microparticles. Also, drug release studies can be conducted over longer periods of time, and with near-infrared light (NIR) to observe the changes in drug release between the fabrications.

Honey-based Silver Sulfadiazine Microsponge-Loaded Hydrogel: In vitro and In vivo Evaluation for Burn Wound Healing.

Silver sulfadiazine has often been used as a topical antibacterial agent for burn wounds. Aim of this study is to develop silver sulfadiazine-loaded microsponge along with honeyimpelled hydrogel for improved burn wound healing activity. Microsponge were prepared by quasi-emulsion solvent diffusion method. Formulation variables such as concentration of emulsifier and Internal phase volume were optimized by using 32 factorial design. Further, SSD microsponge-based Hydrogel was prepared using carbopol 934 and honey as natural healing agents. In vitro drug release, ex vivo drug deposition, skin irritancy study, and in vivo antibacterial activity were evaluated for optimized hydrogel formulations. The MTT assay was used to determine the safety of the optimized hydrogel using epidermal keratinocyte (HaCaT) cell lines. At the 12th hour, in vitro drug release was found to be 85.11±0.89. An adjusted microspongeloaded hydrogel increased medication retention ability in the epidermal layers when compared to the commercial product. There was also less application time, no skin irritation, low cytotoxicity on dermal cell lines, and better wound contraction. The prepared microsponge-loaded hydrogel can serve as a potential alternative for burn wound as compared to the marketed product.

Application of 3<sup>2</sup> Factorial Design in Formulation and Evaluation of Olmesartan Medoxomil Floating Microsponges

The goal of the research was to formulate floating microsponges of Olmesartan medoxomil by 3² factorial design to enhance bioavailability in the gastric region. The quasi-emulsion solvent diffusion method was used to prepare gastroretentive floating microsponges. In this study, the concentration of Eudragit L-100 (X₁) and the concentration of polyvinyl alcohol (PVA) (X₂) were chosen as independent factors at three distinct levels using Design-Expert® software (trial version 13.1.0, Stat-Ease). The dependent variables chosen were the % Buoyancy (Y₁) and % cumulative drug release (Y₂). The percent yield, particle size, bulk density, % buoyancy, % entrapment efficiency, in vitro drug release, the kinetics of drug release, variation of the model, Fourier Transform Infrared Spectroscopy (FTIR) studies, and stability studies for the optimized formulation were conducted. From the design expert, the optimized formula was found to be OLM-MSG7. The magnitude of the coefficient of both X₁ and X₂ showed a positive effect on the buoyancy of the floating microsponges. As the concentration of eudragit L-100, the buoyancy of the microsponges increased. The reason for the buoyancy due to the high concentration of eudragit L-100 may be attributed to the low density of the polymer. However, an antagonistic linear effect of PVA was observed. X₁ and X₂ i.e., polymer concentration and PVA had a positive effect on % CDR of microsponges which indicates that the higher amount of eudragit L-100 contributes to an increase in % CDR. FTIR studies show there is no chemical interaction between the drug and the polymer in the formulation.

Microsponges as Drug Delivery System: Past, Present, and Future Perspectives.

Microsponges are polymeric delivery devices composed of porous microspheres that range in size from 5 to 300 micrometers. These have been explored for biomedical applications such as targeted drug delivery, transdermal drug delivery, anticancer drug delivery, and bone substitutes. The purpose of this study is to conduct a comprehensive analysis of recent developments and prospects for a microsponge-based drug delivery system. The current study analyzes how the Microsponge Delivery System (MDS) is made, how it works, and how it can be used for a wide range of therapeutic purposes. The therapeutic potential and patent information of microsponge-based formulations were systematically analyzed. The authors summarize various effective techniques for developing microsponges, such as liquid-liquid suspension polymerization, quasi-emulsion solvent diffusion method, water-in-oil-in-water (w/o/w) emulsion solvent diffusion, oil-in-oil emulsion solvent diffusion, lyophilization method, porogen addition method, vibrating orifice aerosol generator method, electrohydrodynamic atomization method, and ultrasound-assisted microsponge. Microsponge may reduce the side effects and increase drug stability by positively altering drug release. Drugs that are both hydrophilic and hydrophobic can be loaded into a microsponge and delivered to a specific target. The microsponge delivery technology offers numerous advantages over conventional delivery systems. Microsponges, which are spherical sponge-like nanoparticles with porous surfaces, have the potential to increase the stability of medications. They also efficiently decrease the undesirable effects and alter drug release.

A review on spherical crystallization: A novel technique in the field of particle engineering

In the production of tablets, the direct compression method is mostly used. In comparison to the traditional wet granulation approach, this cannot be used with sensitive pharmaceuticals and also has a lot more processing limitations. Spherical agglomeration is a novel method for creating pharmaceutical dosage forms that are immediately compressible, the process of spherical agglomeration, which improves the powder's qualities such as particle size, shape, flow characteristics, solubility, and bioavailability of pharmaceutical medicinal ingredients, includes transforming tiny crystals into a spherical shape. The spherical crystallization was improved for use with hydrophilic polymers in order to improve the dissolution properties of pharmaceuticals that are poorly water-soluble. The flow characteristics, particle size analysis, compression, and dissolution behaviour of the spherical agglomerates were also improved. Wet spherical agglomeration (WSA) and the quasiemulsion solvent diffusion method (QESD) are the two most used methods for crystallizing spheres. Additionally, these approaches have two additions: the ammonia diffusion system (ADS) and crystallo-coagglomeration (CCA).The neutralization technique is another method used in this procedure. Any of the aforementioned methods can be employed simultaneously for both crystallization and agglomeration. The crystal physical characteristics, including their shape, polymorphism detection using x-ray powder diffraction (XRD), and thermodynamic characteristics using differential scanning calorimetry (DSC), were examined.

SPHERICAL CRYSTALLIZATION: A TOOL TO IMPROVE SOLUBILITY OF DRUGS

Spherical crystallization is a technique in which crystallization and agglomeration are carried out synchronously in one step to form compact spherical form. The most common methods used in spherical agglomeration are quasi emulsion solvent diffusion method, ammonia diffusion system, neutralization technique and co-agglomeration. It succeeded to improve dissolution property of poorly soluble drugs. This can change drug powder properties such as flowability, wettability, packability, compressibility. It has wider applications in improvement of poorly compressible drugs; it has wider application in improvement of compressability of poorly compressible drugs, masking bitter taste of drugs, improving dissolution property, bioavailability and solubility of drugs. Agglomeration crystals converted into tablet forms thus helping us by saving time and reducing cost.

Screening of Adapalene Microsponges Fabrication Parameters with Insight on the In vitro Biological Effectiveness.

The objective of the present study was to scrutinize the microsponges (MS) as a carrier system using Adapalene (ADA) as a model drug. Data modelling was implemented using Plackett-Burman design to identify the main variables affecting the formulation of ADA-MS. The adopted method of preparation for MS was quasi-emulsion solvent diffusion method. The nominated independent variables were volume of organic phase, sonication time, stirring speed, drug percent, polymer type, emulsifier concentration, and method of organic phase addition. As for the dependent variables, they included entrapment efficiency (E.E.%), production yield (P.Y.%), particle size (P.S.) and morphology. Furthermore, selected ADA loaded microsponges (ADA-MS) were in vitro assayed for their biological activities via cytotoxicity, UVA irradiation and cell viability, and antimicrobial activity. The study indicated that the drug percent, polymer type and surfactant concentration have the key significant effect on E.E.% and P.Y.%, while, the drug percent, stirring speed and volume of organic phase have had a significant effect on P.S. and their morphology. Furthermore, ADA-MS had a momentous cytotoxic effect on A431 and M10 cell-lines with exceptional enrichment when the polymer Eudragit RS100 was used. Also, the ADA-MS increased the cell viability after UVA irradiation on HFB-4 cell-line by 14% to 43%, especially when using Ethyl Cellulose as a polymer. Lastly, the antimicrobial activity of ADA against Propionibacterium acnes was boosted when incorporated into MS. The Plackett-Burman design proved its impact in discerning preparation variables affecting the quality of ADA-MS formulation, with heightening of the in vitro biological activities of ADA. Thus, MS was presumed to be an auspicious carrier system for ADA.

Floating Microsponge: An Emerging Drug Delivery System

Floating microsponges are a method to extend gastric residence time, there with the aid of using concentrated on site-responsive medicament liberate withinside the top GIT for locally or systemic effect. Gastro retentive dosage forms (GRDFs) are getting utilized from a totally long term to enhance treatment with numerous main medications. Floating microsponge significantly enhances the therapy of stomach with the aid of using liberating the medication locally and for that reason used for medication selecting at specific organ. This may be sustained over an extended period of time. Floating drug delivery allow extended and non-stop release of the drug to the top a part of Gastro intestinal tract and this expressively amplify the period of drug release and enhance pharmacokinetic of medication which have slim healing window, with the aid of using this method dosing frequency and affected person compliance is increased. A microsponge’s drug delivery system is a particularly cross-linkage, spongy, polymeric microsphere, polymeric device consisting permeable microspheres. Microsponges are prepared with the aid of using numerous techniques consisting of liquid-liquid suspension polymerization and quasi emulsion solvent diffusion method. Microsponge,s preparations are strong over variety of pH 1 to 11; microsponge,s preparations are strong on the temperature as much as 1300C well suited with maximum vehicles and ingredients. The present assessment introduces microsponge,s technology at the side of its techniques of preparation, characterization, advantages, evaluation and release mechanism of microsponge,s drug delivery system, advertised product and up to date studies regarding microsponge.
 Keywords: Floating microsponge, Oral administration, Controlled release, Quasi emulsion, Target release.

Formulation and evaluation of orlistat loaded microsponges for the treatment of obesity

The motivation behind this investigation was to design novel drug delivery system containing orlistat micro sponges. Microsponges containing orlistat and Ethyl cellulose/ Eudragit RS 100 prepared by quasi emulsion solvent diffusion (Technique) method. The formulations were prepared step by step increases Drug: polymer ratio. The particle size (Malvern analyzer), Surface Morphology and structure examination (SEM) Production yield, Drug entrapment Efficiency and in vitro drug release studied of microsponges were examined. Shape or surface morphology and topography of the orlistat microsponges were examined by scanning electron microscopy. The drug orlistat disperse in GIT for better therapeutic effect as microsponges disperse freely in GIT. To improve absorption of orlistat so as to enhance bioavailability, micro sponges is used as delivery systems which show better absorption and bioavailability then other dosage form of orlistat. The particle size were prepared microsponges was observed in the range of 50.45 ± 0.85µm to 57.77 ± 1.35µm. The drug entrapment of the orlistat microsponges was observed in the range of 73.23 ± 0.23 to 83.41 ± 1.17 % The in vitro drug release study of the microsponges over 8 hour range from 59.28 ± 0.41% to 73.16 ± 0.89 %. The objective of this research work was to formulation and evaluation of orlistat loaded microsponges for management of obesity disease. Microsponges drug delivery system landscape have been highly and rapidly evolving. They are allowing for novel product form. Microsponges are safe biologically and extraordinary preferred position programmable release. This delivery system are being integrated to optimize the efficacy or free streaming effectiveness treatment.

DEVELOPMENT OF GEL-LOADED BASED MICROSPONGES OF CLARITHROMYCIN FOR THE TREATMENT OF TOPICAL DELIVERY

Objective: The purpose of the present study aims to design a novel drug delivery system containing clarithromycin microsponges and to prepare microsponge gel. Methods: The microsponges were prepared by quasi-emulsion solvent diffusion method using polymer eudragit RS-100. All the formulated microsponges were subjected to various evaluation parameters such as production yield, encapsulation efficiency, particle size analysis, and in vitro drug release study. Results: In vitro drug release of all the formulations was found to be 47.36% to 87.32%. Formulations F2, F3, and F4 show the best drug release from all formulations within 480 min. The optimized microsponge formulations F2, F3, and F4 were further formulated as gel formulations for topical delivery. Prepared gel was evaluated for physical parameters like pH, spreadability, viscosity, drug content, in vitro diffusion study, and stability study. All gel formulations showed drug release of 63.18±0.52%, 76.4±0.51%, and 72.93±0.42% from formulations GF1, GF2, and GF3, respectively, within 480 min. The microsponge gel formulation GF2 showed the controlled release of clarithromycin for 480 min, which was 76.4±0.51%. The stability study shows no significant changes in all parameters. Conclusion: With the revealed results by different evaluation parameters, it is concluded that the microsponges drug delivery system has become a highly competitive and rapidly evolving technology and more and more research is carried out to optimize the cost-effectiveness and efficacy of the therapy.

Formulation and Evaluation of Hydroxypropylmethylcellulose-dicyclomine Microsponges for Colon Targeted Drug Delivery: In Vitro and In Vivo Evaluation.

The objective of the present study was to design novel colon targeted delivery of Dicyclomine Hydrochloride (DCH) microsponges. Microsponges (MS1-MS4) based on different ratios of Hydroxypropylmethylcellulose (HPMC) and DCH were prepared by quasi-emulsion solvent diffusion method. Micro-sponges were analyzed by determining percent yield, encapsulation efficiency, drug content, drug-polymer compatibility and thermal stability. Kinetic analysis of thermal stability data was done by Chang method, Friedman method and Broido method. In vitro dissolution study was carried out at pH 1.2, pH 6.8 and pH 7.4 at different time intervals. Results showed that there was no chemical interaction between DCH and HPMC in all microsponge formulations. Production yield, drug content and encapsulation efficiency were enhanced on increasing the drug-polymer ratio. Thermal stability of all the micro-sponges was greater than that of pure drug. In vitro drug release was decreased on increasing the polymer concentration at different pH levels. The newly prepared micro-sponges based on HPMC were confirmed as a promising means of colon-targeted delivery of DCH. An HPLC method was developed and validated for the bioequivalence study of newly designed microsponges. Pharmacokinetics parameters were calculated using the linear trapezoidal method after single oral administration of microsponges in white albino rabbits. Pharmacokinetics results indicate an enhancement in the value of t1/2, tmax, Cmax and AUC0-t of DCH in the microsponges as compared to standard DCH showing enhanced bioavailability of the drug after microsponges formation. The current study shows a new approach for colon-specific delivery of DCH based on microsponges.

Statistical Design for Formulation Optimization of Diclofenac Sodium-Loaded Ethylcellulose Microsponges

For a better use of the drug, a decrease in side effects, an improvement in effectiveness, and a uniform release of the active ingredients, sustained-release forms have been developed. The objective of this study is to estimate the effect of the factors on the responses involved in the formulation of Diclofenac Sodium (DC) loaded ethylcellulose (EC) microsponges (MP) using Central Composite Design (CCD). Quasi emulsion solvent diffusion method was used to formulate MP. The ratio of ethylcellulose to Diclofenac Sodium and polyvinyl alcohol (PVA) concentration (w/v%) were selected as independent variables for CCD. Entrapment efficiency (EE) and production yield (PY) were selected as dependent variables. The optimal formulation was characterized by Fourier Transform Infrared (FTIR), Optical Microscopy, and in vitro release. Optimized MP showed an EE of 31.02% and a PY of 66.44%, FTIR studies revealed no chemical interaction between drug and polymer used, MP were spherical and present an average size of 9.21±0.3µm. Kinetic studies revealed that drug release from optimized formulation followed Higuchi model. The results demonstrated the effectiveness of proposed design for development of DC microsponges for the sustained release.

Formulation, Characterization, and Antibacterial Study of Microsponge- Loaded Gel of Clarithromycin for Topical Drug Delivery

Background: Microsponge drug delivery systems comprise spherical and porous micro-spheres for prolonged topical drug delivery. These systems considerably reduce the undesirable side effects, offering improved patient compliance and reduced dosing frequency. Objective: The present study focused on developing topical controlled release preparations of microsponges-loaded gel of clarithromycin to cure bacterial skin infections. Materials and Methods: Four batches of microsponges (F1, F2, F3, and F4) of clarithromycin (CLR) containing fixed amounts of clarithromycin (100 mg), dichloromethane (5 ml), polyvinyl al-cohol (5 % w/v) and distilled water (25 ml) with varying polymer concentrations were prepared by the quasi-emulsion solvent diffusion method and evaluated for % Production Yield, % drug content, % encapsulation efficiency, particle size, polydispersity index (PDI) and % drug release characteris-tics. The selected microsponge formulation (F3) was incorporated in Carpopol 934 gel for topical application. The prepared gel (CLRMS-F3 Gel) was evaluated for physical characteristics, pH, spreadability, viscosity, and in vitro drug release. Furthermore, the gel formulation was compared with pure clarithromycin gel for antibacterial activity against the gram-positive (S. aureus) and gram-negative strain (E. coli.) using the cup and plate method. Results and Discussion: The F3 microsponge formulation exhibited a production yield of 83.75%, drug content (21.5 ± 0.50 %), and encapsulation efficiency of 86.04 ± 2.30%. Their particle size was satisfactory (3.80 ± 0.01 μm), and they were found to be spherical and porous in nature. F3 microsponges released 69.36 ± 1.27% of the drug over a period of 8 hrs and were incorporated into the gel formulations. The gel prepared using F3 microsponges was transparent, homogenous, and exhibited a pH of 6.8 ± 0.02, spreadability of 9.92 ± 0.44 g/cm, and viscosity of 35370.17 ± 493.09 centipoises. The CLRMS-F3 gel released 82.13 ± 0.47% drug in 12 hrs using a zero-order kinetic. The antibacterial activity studies revealed a higher potency against both S. aureus and E. coli of the prepared CLRMS-F3 gel compared to pure CLR gel and azithromycin standard. Conclusion: Based on the above study, it may be concluded that microsponges’ gel formulation can be potentially useful in improving topical drug delivery of antibacterial agents and can give better therapeutic efficacy.