QUERCETIN LOADED RIFAMPICIN-FLOATING MICROSPHERES FOR IMPROVED STABILITY AND IN-VITRO DRUG RELEASE

Prashant Lakshaman Pingale^1*, Sunil Vishwanath Amrutkar²

ABSTRACT

After HIV, tuberculosis (TB) is the world's second most frequent disease. MTB (Mycobacterium tuberculosis) is a major infectious disease that poses a considerable public health issue. Fixed-dose drug combination microspheres appear to be a better option for long-term, regulated medication therapy. The drugs could be given orally once a week to encourage patient compliance. For long-term pharmaceutical therapy, fixed-dose drug combination microspheres appear to be a superior option. Oral administration is the most common and favored mode of pharmaceutical administration. Drug release is modulated throughout the GI tract with oral controlled-release (CR) formulations. Swelling and expanding systems, floating systems, forms of the mucoadhesive systems of high-density dose, and magnetic systems have all been employed. The goal of this study is to develop rifampicin-floating microspheres that will increase gastric retention time. The influence of quercetin on in-vitro drug release has been looked. The efficiency of entrapment was determined to be 76.50 percent. After 8 hours, the percentage buoyancy was observed at 61.50. In gastric media, the microspheres produced displayed extended drug release, indicating that they could be employed for long-term anti-tubercular medicine delivery.

Keywords: Quercetin, Rifampicin, Floating microspheres, Bioavailability, Drug release

Introduction

MTB (Mycobacterium tuberculosis) is an infectious disease that poses a considerable public health problem and infects hundreds of millions of old people around the world. MTB treatment, including MDR-TB (multidrug-resistant tuberculosis), is a major concern. Microsphere-based medication delivery can increase drug bioavailability and minimize dose frequency [1].

Microspheres have been investigated in the treatment of tuberculosis and HIV for decades. Fixed-dose drug combination microspheres appear to be a better option for long-term, regulated medication therapy, as well as being more cost-effective and boosting compliance. The drug in the form of microparticles is released for 3–5 days in plasma and up to 9 days in organs. The drugs could be given orally once a week to encourage patient compliance [2].

Oral administration is the most common and favored mode of pharmaceutical administration. This could be due to the ease, with which it is administered, as well as patient compliance and formulation flexibility. It does, however, have limitations due to the wide diversity of biochemical and physiological conditions found in the gastrointestinal system. Furthermore, the development of oral dosage forms has been hampered by first-pass drug metabolism [3].

Oral controlled-release (CR) formulations, which enable regulated drug release throughout the GI tract, constant drug concentration maintenance in the serum for prolonged periods, bioavailability improvement, effectiveness of therapeutic, and decrease dose allowance, can help with these concerns. Longer gastric retention aids in the controlled release drug delivery system predictable stomach retention for an extended period. Floating systems, dosage forms of mucoadhesive, systems of high-density and super porous hydrogel have all been used. Traditional dosage forms have fewer design choices than these technologies [3, 4].

Gastro-retentive preparations are a sort of formulations that floats in gastric juice for more duration. They allow pharmaceuticals to be dispensed in a controlled and predictable manner. Single and multiple unit variants of floating drug delivery systems (FDDS) are available [5].

Many herbal treatments and herbal extracts have limited or no in-vivo efficacy due to insufficient lipid solubility or unsuitable molecular size. Novel drug delivery systems have now opened the way to the development of herbal drugs with higher bioavailability. Liposomes, microspheres, transferases, and other new carriers have been described for the successful modified delivery of numerous herbal drugs [6].

With gastroretentive floating microspheres, drug bioavailability and controlled distribution could be improved. The effect of quercetin on drug release in vitro was investigated.

Materials and Methods

Lupin Pharmaceutical Aurangabad, India gifted a sample of Rifampicin. Quercetin was procured from Yucca Enterprises, Mumbai, India. Preparation of microsphere required by the Polymers such as ethylcellulose hydroxypropyl and methylcellulose were procured from Colorcon Asia Ltd., Goa, India. Analytical grade chemicals were used.

Microspheres Preparation

The solvent evaporation approach was used to make quercetin-loaded rifampicin floating microspheres. In a 1:1 mixture of ethanol and dichloromethane, ethylcellulose, hydroxypropyl methylcellulose, rifampicin, and quercetin were dissolved. This solution was gently placed in a percentage of H₂O containing 0.01, a mixture of Tween 80 and stirred together for 40minsandletthe dissipation of volatile solvent. The microspheres were filtered, water-washed, and vacuum-dried [7, 8]. Micromeritic characteristics of quercetin-loaded rifampicin microspheres are shown in Table 1.            

Table 1. Micromeritic characteristics of quercetin loaded rifampicin microspheres

Microspheres Characterization

Fourier Transform Infra-Red Analysis (FT-IR): The physical drug combination, formulation, extract of herbal, and polymerwith the use of Fourier Transform Infrared (FT-IR) spectroscopy were all examined. The polymers and other excipients in the drug if compatible and evaluated by FTIR [9].

Differential Scanning Calorimeter (DSC) Study:  aluminium samples of 5-10 mg pans were weighed, and below stationary air at a heating rate of 10°C/min scanned over a temperature range of 250° to 30°C [10].

Percentage Yield: The overall microspheres weight produced was compared to the overall polymer weight, medication, and bio-enhancers utilized in the formulation to determine the product of microspheres [11, 12].

The yield percentage of the microsphere was calculated utilizing the ensuing formula:

Particle Size Analysis: A microscope analysis was used to assess the size of quercetin-loaded rifampicin microspheres. As illustrated in Figure 1, no major visible surface flaws are formulated in microspheres withnearly spherical. Under a Motic microscope at 40 X magnification, photomicroscopic images illustrate the size of individual particles [12].

Percentage of buoyancy In-vitro: (50 mg) of Hollow microspheres were agitated at 100 rpm in HCI (100 ml) of 0.1 N. Filtration was used to separate the microspheres. The desiccator is used to dry microspheres overnight. The formula below was used to compute the percent buoyancy [12]. Floating ability at different time intervals is shown in Figure 2.

Percent Drug-Entrapment Efficiency: In 10 mL methanol, quercetin-loaded rifampicin microspheres (10 mg) were shaken for 24 hours. Shimadzu 1800 UV-Vis spectrophotometer were used to measure the resulting solution from the extracted drug, and the concentration (Wd) of the drug entrapped in the microsphere was calculated using a calibration curve. Each technique was repeated three times in total [13]. The following formulae were used to calculate the drug-loading ratio and entrapment efficiency percentages:

Where,

Wd is the calculated weight of microsphere (g), 

Wm is the weight of drug-loaded microspheres (g)

Measurement of Bio-Adhesion: Microspheres were distributed throughout the small intestine of an albino rat (area 2 cm²) and kept in a humidity temperature-controlled cabinet. The mucosal lumen was thoroughly cleansed with pH 6.8 phosphate-buffered saline and dried in a hot air oven at 70⁰C as shown in Figure 3 [14].

The following formula was used to calculate the percentage of bio-adhesion:

Table 2. Particle size, percent yield, percent entrapment of drug, percent bio-adhesion, percent drug release, andzeta potential of quercetin rifampicin microspheres

Surface Charge: The zeta potential of microparticle formulations was also measured since, as is well known, it affects particle stability. Positive or negative zeta potential values that are more apparent in principle likely to stabilize particle suspension. The spheres do not aggregate due to electrostatic repulsion between particles with the same electric charge. Table 2 shows that the microspheres generated by the solvent evaporation process were negatively charged [10].

Drug release In-vitro: The discharge of drug quercetin-loaded rifampicin microspheres was tested using a USP XXXI basket-type dissolution apparatus. A weighted quantity of equal microspheres was placed to 50 mg of drug in the basket.  Replicated gastric juice was utilized as the dissolution medium, which was held at 37°C and 100 rpm. Sample of a 5 mL was taken once a 30-minute interlude and processed for 1 hour by a membrane filter.  For the next 8 hours, further samples were obtained every hour, and to maintain the preliminary dimensions of the dissolving fluid, a fresh dissolving fluid of 5 ml was supplementary after each withdrawal. The samples were spectrophotometrically examined at 475 nm to regulate the amount of drug in the dissolving fluid. Triplicate has carried out the drug release study. Drug release from quercetin loaded microspheres is shown in Figure 4 [12, 15, 16].

Drug Release Kinetics: The solution of the in vitro dissolution investigation of microspheres were fixed with countless equalities of kinetic, such as zero-order (release percentage versus time), first-order (log percentage of cumulative drug remaining versus time), and, to comprehend the mechanism and kinetics release of drug by Higuchi's model (square root of time versus release of drug percentage). Regression analysis of the above plotscreated bythe linear curves, the correlation coefficient (R2) values were determined. In vitro, quercetin-loaded rifampicin microspheres release medicine as seen in Figure 4.

Results and Discussion

Hollow microspheres were produced utilizing the method of solvent evaporation with a 1:6 ratio of HPMC and EC using quercetin as a herbal bioenhancer in this investigation. 76.50 percent of the medications were discovered to be entangled. The hollow microsphere's lag time was discovered as zero. At a 1:6 ratio, HPMC and EC displayed good buoyancy time with no lag time. In the simulated gastric fluid, about 15% of the drug was evacuated within an hour.

Conclusion

We attempted to construct floating quercetin-loaded rifampicin microspheres of HPMC and EC to improve tuberculosis management and preserve rifampicin release in the stomach. Better trapping and longer release patterns were observed in the research. Furthermore, the new system is stable.

It is well established that when the solubility of a medication diminishes, so does the amount of time available for dissolution, and therefore the time of conveyance becomes a critical factor affecting drug immersion. This may perhaps assist to boost rifampicin bioavailability, which is crucial for tuberculosis treatment. For reconstitution, the microspheres possibly will be compressed into tablets, packed into capsules, or molded into oral solutions.

Furthermore, the formulation's stability was compared to that of microspheres without quercetin, and it was observed that even after 6 months of stability testing, the quercetin-loaded microspheres showed no change.

Acknowledgments: None

Conflict of interest: None

Financial support: None

Ethics statement: None

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