This study was focused on forming Erythromycin microbeads using ionotropic gelation technique to improve its efficacy. This involved immersing a mixture of Erythromycin and polymers such as chitosan and gelcarin into various crosslinking solutions. Scanning electron microscopy was used to evaluate the surface morphology of the microbeads and this showed they varied in shape and texture depending on crosslinking solution used. Functional groups present in the infrared spectra of the microbeads were compared with infrared spectra of pure erythromycin to confirm the incorporation of erythromycin into the beads. The type of crosslinking solution used in the formation of the beads and test media used for evaluation was found to affect the swelling properties of the beads. The concentration of drug loaded into the bead was found to have no effect on the swelling properties. A mathematical model was used in determining the water diffusion behavior of the beads. The result showed erythromycin microbeads as a promising delivery system is in improving drug therapy.
1.0 INTRODUCTION AND LITERATURE REVIEW
1.1 DRUG DELIVERY
The method or process of administering or delivering an active pharmaceutical compound through one of the common routes in order to attain a therapeutic effect in man or animals is known as drug delivery. There are various routes in which drugs can be delivered to the target specie. In humans it could be oral, nasal, pulmonary or parenteral with the nasal and pulmonary routes gaining more importance in recent times. For this purpose, a number of drug delivery systems have been formulated and are being investigated for nasal and pulmonary routes. Some of these systems are liposomes, proliposomes, microspheres, gels, prodrugs, among others (Tiwari G et al.,2016).
Polymer drug conjugate is designed so that the drug is delivered in a controlled manner with the release from the conjugate occurring over a defined time interval.
A controlled release drug delivery system should be able to maintain optimum therapeutic drug concentration in the blood. It should be able to enhance the activity duration for short half-life drugs as well as eliminate side effects, frequent dosing and drug wastage. To achieve these, the chemical and physical properties of the drug, the route of administration, the nature of the delivery vehicle, the mechanism of drug release as well as other factors would have to be considered.
1.1.1 ADVANTAGES OF DRUG DELIVERY SYSTEMS (Coelho J.F et al.,2010)
- The duration of action of the drug being delivered is prolonged when using drug delivery systems.
- The bioavailability of the drug is increased.
- Drug loss and deterioriation is highly reduced.
- Minimal side effects is associated with drug delivery systems.
- The frequency of dosing and administration of the drug is reduced.
- Fluctuations in plasma drug concentration is greatly minimized.
- It enhances patient compliance and drug use.
1.1.2 DISADVANTAGES OF DRUG DELIVERY SYSTEMS (Coelho J.F et al.,2010)
For everything that has an advantage, there is always a disadvantage. The disadvantages of DDS includes;
Risk of formulation materials being toxic.
The degradation products may be harmful.
Some forms of DDS may involve surgical intervention either on application or removal of the system.
DDS devices may be uncomfortable to patients in the cause of usage.
High cost of products.