Formulation And Evaluation Of Fluconazole Loaded Microsponges Gel For Topical Drug Delivery System.

Table No.1 Carrier System for Drug Delivery

MICROSPONGE: AN APPROACH FOR TOPICAL DELIVERY 

Microsponges are a new, regulated medicinal product with a wide range of uses. They have the capacity to encapsulate a variety of medications, both liquid and solid. compliance. Overall, microsponges offer a promising approach in pharmaceutical formulations, enhancing drug delivery outcomes and patient satisfaction.  By taking advantage of the special structure and physiology of human skin, microsponges offer a significant advantage in the administration of dermatological medicines. They provide increased effectiveness when applied to human skin. They minimize local side effects while providing increased efficacy. is essential to their topical Microsponges' remarkable entrapment effectiveness, which enables them to absorb more than six times their own weight, is one of their main advantages. Even at high temperatures and over a wide pH range of 1 to 11, these microsponges show remarkable stability. compatibility when added to liquid or semi-solid dosages and suspended in different carriers forms by giving the medication a regulated release. Microsponges add to the product's elegance by assuring stability and non-irritating medication release. qualities that enhance patient applicability.

DEFINITION:

The tiny sponge-like particles that make up microsponges are porous, polymeric, microscopic drug delivery systems that have the ability to trap active medicinal components within their network. They are usually between 5 and 300 µm in diameter and have many interconnected pores that enable targeted, regulated, and prolonged drug release. By releasing the medication gradually at the site of action, microsponges increase the stability of medications, lessen discomfort, and boost efficacy. These qualities make them popular in topical, oral, and cosmetic formulations to increase patient compliance and therapeutic efficacy.

Fig no.1 Structure of Microsponges

Higher concentrations of active substances are needed to produce therapeutic effects because many conventional drug delivery methods are ineffective at delivering medications. Because of these restrictions, sophisticated drug delivery methods are being investigated more and more to accomplish site-specific and regulated drug release. A.Polymer-based microspheres with a substantially cross-linked structure are known as microsponge systems. They can encapsulate a wide range of active pharmacological substances since they are sufficiently flexible. These qualities make microsponges popular for applications involving controlled and extended drug administration.Microsponges are designed to effectively administer a pharmaceutically active drug at the lowest feasible dose, minimize adverse effects, and enhance stability, elegance, and flexibility in formulation. The drug release profile can also be changed with these. The microsponge system can stop an excess of a component from building up in the dermis and epidermis. These goods are often packaged in conventional ways and contain a very high concentration of active substances. Microsponges come in conventional forms like lotions, gels, or creams and have a fairly high concentration of active chemicals. A variety of active substances, including anti-infective, anti-fungal, and anti-inflammatory drugs, can be transported via microsponges, which are polymeric delivery systems made of porous microspheres.

Table No.2 List of marketed products

5. Advantages

1. Avoidance of First Pass Metabolism.
2. Suitability for self-medication.
3. Microsponges remain stable at pH 1-11 and 130°C.
4.  Microsponges are suitable with most vehicles and substances.
5. Enhances thermal, chemical, and physical stability.
6. Avoidance of absorption challenges.
7.  Easy termination of medication if necessary.
8. Avoidance of gastrointestinal incompatibility.
9. Microsponges are biosafe and allow programmable release.
10. Enables immiscible product incorporation.

5. Disadvantages

1. Skin irritation or dermatitis may occur due to the drug or excipient and this can lead to discomfort and adverse reactions.
2. Low drug loading capacity.
3. Use of organic solvents may cause toxicity.
4. Complex and time-consuming preparation.
5. Risk of initial burst release.
6. Scale-up process is challenging.
7.  Moisture-sensitive system.
8. Poor stability in presence of light and high temperature.
9. Cannot incorporate water soluble drugs.

Objectives

1. To formulate Fluconazole-loaded microsponges using suitable polymer(s) and preparation technique.
2. To optimize formulation parameters such as drug–polymer ratio, solvent system, and stirring conditions
3.  To evaluate the prepared microsponges for particle size, morphology, production yield, entrapment efficiency, and drug loading.
4. To incorporate optimized microsponges into a suitable topical gel base.
5. To assess the potential of Ibuprofen microsponges for sustained drug release and improved topical delivery.

MATERIAL AND METHODS:

Material: Fluconazole, Eudragit RS 100, Ethyl cellulose, PVA, Dichloromethane, Methanol, glycerol.

Methods:

Fluconazole microsponges were prepared by quasi emulsion solvent diffusion method by using different drug.

Quasi-Emulsion Solvent Diffusion Method:

The microsponges containing the anti-fungal drug  Fluconazole as the core material was prepared by Quasi emulsion Method according to the formula given in table no. 3 the process involved formation of quasi-emulsion of two different phases i.e. internal phase and external phase similar to the emulsion.

1.  The drug-polymer solution's internal phase prepared in 10 milliliters of dichloromethane, a volatile solvent.
2. 2) After that, it was vigorously stirred into the external phase, which included the aqueous 1% (1g/100 ml water) polyvinyl alcohol (PVA) solution.
3. A sufficient amount of glycerol (1-2 ml) was injected to promote plasticity. Discrete emulsion globules known as quasi emulsion globules are created as a result of stirring.
4. The stirring was continued up to 3 hrs till the insoluble, rigid microparticles i.e. microsponges is formed.
5. Then it was filtered to separate the microsponges and dried it oven for 3hrs .                                                           

Fig no.2.Process of stirring

Table no.3.Formula for Microsponges formulation

Table No.4: Formula for Gel formulation

EVALUATION PARAMETER OF Fluconazole MICROSPONGES:

1. Physical Appearance:

The formulation's physical characteristics, including color, consistency, and the existence of any obvious irregularities, were evaluated visually.

2. Percentage yield:

It is necessary to gather and weigh the microsponges produced from different formulations. In this case, the total weight of the medication and polymer utilized in the production procedure will be divided by the actual weight of the microsponges. This computation makes it possible to evaluate the proportion of medication contained in the microsponges, offering information on the formulation's effectiveness.
The yield percentage was computed using the formula that follows

3. Drug content:

Each batch of microsponges containing 100 mg of fluconazole should be accurately weighed and crushed. After that, the powder should be put in a 100 ml volumetric flask and adjusted with pH 7.4 phosphate buffer. To bring the solution up to par, phosphate buffer should be added after it has been filtered. Whatmann filter paper No. 44 was then used to filter the mixture. A precise amount of the solution (1 ml) should be taken after filtering and diluted up to 10 ml with pH 7.4. Following filtering, a precise amount of the solution (1 ml) should be obtained and diluted with pH 7.4 phosphate buffer up to 10 ml. A precise volume (1 ml) should be pipetted out of this diluted solution, and pH 7.4 phosphate buffer should be used to further dilute it up to 10 ml. A spectrophotometer should be used to measure the final solution's absorbance at 264 nm.

%Drug Content= Actual drug content of microsponges/Total amount of microsponges ×100

4. Optical microscopy:

Microsponges' surface appearance and form are examined using microscopy. A tiny sample is put on a glass slide and examined under a microscope.

5. Entrapment efficiency (EE)/ Loading efficiency:

Actual Drug Content: 100 mg of precisely weighed microsponges were used. They were ground into a powder and extracted using a 100 ml technique. Additionally, it was serially diluted using phosphate buffer 7.8 at pH 7.4. Ibuprofen drug concentration was determined by measuring absorbance in a UV spectrophotometer at 260 nm using pH 7.4 phosphate buffer as a blank. The investigations were conducted in duplicate. The entrapment effectiveness and real drug content were purposefully chosen as:

• Actual drug content (%) =(Mact/Mms)*100
• Entrapment efficiency (%) =Mact/Mthe)*100

where Mthe is the theoretical amount of ibuprofen in microsponges, Mms is the weighed quantity of microsponges, and Mact is the actual amount of ibuprofen in microsponges.

6. pH:

A digital pH meter was used to determine the formulation's pH. The formulation's pH was measured three times, and the average value was determined.

7. Particle size:

Optical microscopy was used to measure the prepared microsponges' particle size. An ocular micrometer and a stage micrometer were attached to the optical microsponges. The micrometer in the eyepiece was calibrated. Using an optical microscope, the diameters of over 200 microsponges were measured at random.

• Calibration of eyepiece micrometer
• One division of the stage micrometer = 0.01 mm = 10 µm

µ=(SM/EM) ×10

Were, µ- correction factor

SM- Reading of stage micrometer which coincides

with reading of eyepiece micrometer (EM).

8. Zeta potential:

To assess the surface charge and electrostatic stability of the prepared microsponges, zeta potential was calculated. The degree of repulsion between similarly charged particles scattered across the medium is revealed by the measurement. By preventing particle aggregation and sedimentation during storage, a sufficient zeta potential value denotes strong physical stability. A zeta potential analyzer based on electrophoretic mobility was used for the analysis. The formulation's stability and suitability for additional pharmaceutical uses are indicated by the acquired zeta potential values. Improved dispersion stability and homogeneity of the microsponge system are suggested by higher absolute zeta potential values.

EVALUATION OF MICROSPONGES LOADED GEL:

Evaluation of Gel Loaded with Microsponges

1. Visual inspection of gel

The, formulations were subjected to observed for color, consistency, quality, uniformity, homogeneity, and dispersion of gel loaded microsponges are examined by visual observation.

2. pH Measurement

The gel loaded with Microsponges was subjected to determination of pH by utilizing digital pH meter. 5 g gel was suspended in 45 ml double distilled water, and solution pH was measured.

3. Spreadability Studies of Gel Loaded with microsponges:

The gel loaded with Microsponges batch was subjected to spreadability studies by using and glass slide apparatus. It comprises of two slides upper movable slide and lower non-movable slide. The weight loading of about 20 gm were added to the pan and time was noted for upper slide to confine totally from the fixed slides. Spreadability was then determined by utilizing the formula.

S= M x L/T (g.cm/s)

Where,

S= Spreadability;

 w= weight tide to upper slide;

 L= length of glass slide;

 T= time taken to separate the slide completely from each other.

4. Washability Test

The gel is applied on the skin surface and washed with water The ease of removal and residue remaining is observed A good gel should be easily washable without leaving significant residue.

5) In-vitro Antifungal Activity

The inoculum of the microorganism was prepared from the fungal cultures.

15ml of Saubroad agar (Hi media) medium was poured in clean sterilized Petri plates and allowed to cool and solidify.

100 µl of broth of fungal strain was pipette out and spread over the medium evenly with a spreading rod till it dried properly.

Wells of 6mm in diameter were bored using a sterile cork borer. Solutions of the compounds (100µl/ml) were prepared in DMSO and 100µl of prepared test solutions and standard was added to the wells. The petri plates incubated at 37 0C for 24 h. Miconazole (1mg/ml) was prepared as a positive control and DMSO was taken as negative control. Antifungal activity was evaluated by measuring the diameters of the zone of inhibitions (ZI) all the determination were performed in triplicates

RESULTS AND DISCUSSION:

1. Results of visual inspection of fluconazole microsponges:

 The color and nature of the F1-F2 formed microsponges were determined to be white and powdered, as indicated in Table No. 4. This indicates that the resulting microsponges pass the visual test for the standards.

Table no: 4 Results of Visual Inspection of fluconazole microsponges

Fig no.3.Physical appearance of Microsponges

2. Percentage yield:

It was discovered that the Fluconazole drug's percentage yield in microsponges was 50%. For some applications, such topical or transdermal distribution, a PE of 50–70% is ideal.
The yield percentage was computed using the formula that follows:

% Yield= Practical yield of microsponges ×100

                  Total weight of drug and polymer 

             = 1.5/3.5×100

               =50%

3. Drug content:

A UV-visible spectrophotometer was used to measure the drug content of the manufactured fluconazole-loaded microsponges. The drug content was represented as % w/w after the absorbance readings were transformed into concentration .The medication content of the formulation was 85%

Fig no 4: Determination of drug content

4. pH:

The microsponges solution's standard range was 1–11, and its optimal pH of 6.48 was discovered.

Fig No.5. Determination of pH

5. Optical Microscope:

 The prepared microsponges were consistently distributed and largely spherical in shape, according to optical microscopy. The particles had smooth surfaces and seemed distinct. There was no noticeable particle clumping or aggregation.

6)Results of particle size:

Zeta sizer analysis using the Microtrac Zeta sizer for microsponges. The Poly Dispersity Index (PDI) value was 0.566, which was appropriate for particle size determination, and the average microsponge particle size in the diluted sample with water was 5946(d) nm.

Fig No.6. Result of particle size

7) zeta potential:

Zeta potential was measured at a temperature of 20.07°C, a viscosity of 1 mPa.s, and an electrophoretic mobility of 0.48 µm2/Vs. Microsponges are stable in preparation because their zeta potential was discovered to be 28 mV.zeta potential used to determine the particle surface charge.

Fig No.7.zeta potential

8)Entrapment efficiency:

For all microsponges, the loading efficiency of Fluconazole microsponge formulations ranges from 33.17 to 82.76%, which is the maximum loading efficiency. This was discovered for the formulation F2, which contained more medication.Fluconzole and ethyl cellulose are suggested.

RESULTS OF GEL LOADED WITH FLUCONAZOLE MICROSPONGES

1. Results of Visual Inspection of Gel Loaded with Microsponges

      The formulated gel loaded with Fluconazole microsponges were inspected for their color and appearance. The gel loaded microsponges batches (F1) as shown in Table no: 7, were appearing transparent white with uniformly distributed microsponges,

Table No.8. Results of Visual inspection of gel