Shyamala, J K (2017) Formulation Design, Development and Invitro Evaluation of Abacavir Sulphate Gastroretentive Microspheres. Masters thesis, J. K. K. Nattraja College of Pharmacy, Komarapalayam.
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Abstract
INTRODUCTION: During the last three decade many studies have been performed concerning the sustained release dosage form of drugs, which have aimed at the prolongation of gastric emptying time (GET). The GET has been reported to be from 2 to 6 hours in humans in the fed state. Accordingly orally, sufficient bioavailability and prolongation of the effective plasma level occasionally cannot be obtained. Gastric emptying of dosage forms is an extremely variable process and ability to prolong and control the emptying time is a valuable asset for dosage forms, which reside in the stomach for a longer period of time than conventional dosage forms. Several difficulties are faced in designing controlled release systems for better absorption and enhanced bioavailability. One of such difficulties is the inability to confine the dosage form in the desired area of the gastrointestinal tract. Drug absorption from the gastrointestinal tract is a complex procedure and is subject to many variables. It is widely acknowledged that the extent of gastrointestinal tract drug absorption is related to contact time with the small intestinal mucosa. Thus, small intestinal transit time is an important parameter for drugs that are incompletely absorbed AIM AND OBJECTIVES: The aim of the present work was to formulate and evaluate sustained release floating microspheres of Abacavir Sulphate. Abacavir Sulphate is used to in combination with other antiretroviral agents, are indicated for the treatment of human immunodeficiency virus (HIV-1) infection. Existing marketed products of the formulation has a dose of 300mg with dosing frequency of two to three times a day and very shorter biological half-life of about 1.54±0.63hour. Further a floating sustained release microsphere has been endeavored by employing polymer combination system to achieve effective plasma concentration with reduced side effects. Floating drug delivery system have a bulk density less than gastric fluids and so remains buoyant in the stomach without affecting gastric emptying rate for a prolonged period of time. Floating microspheres of Abacavir Sulphate for improving the drug bioavailability by prolongation of gastric residence time. Solubility of the selected drug decrease with increase in pH making stomach better site of absorption. Hence an attempt has been made to formulate a GI floating microsphere of the selected drug. Floating microspheres helps in retaining the microspheres in stomach fluids for longer duration and better absorption with site specificity. Formulation techniques involved solvent evaporation method and optimization of stirring speed technique and hydroxylpropyl methylcellulose (HPMC) as the rate controlling polymers. CONCLUSION: The ultimate goal for sustained drug release is to maximize therapeutic activity while minimizing the negative side effects of the drug. In this regard, floating microspheres have emerged as a novel drug delivery system to treat HIV with Abacavir sulphate. The type of polymer affects the drug release rate and the mechanism. Polymer swelling is crucial in determining the drug release rate and is also important for flotation. A lesser FLT and a prolonged floating duration could be achieved by using different polymer combinations. In this study sustained release Floating Microsphere approach for Abacavir sulphate purposes that with hydrophilic polymers the GI retention can be enhanced and reduce frequency of dosing, thereby minimizing the occurrence of side effects, site specificity, increase the effectiveness of the drug and better patient compliance This gives a signal to extending this approach to similar combinations of drugs used in clinical practice so as to improve bioavailability of poorly absorbed drugs in GIT. When these floating microspheres compared to other floating dosage forms like floating tablets have bulk density less than gastric fluid and so remain buoyant in the stomach for prolonged period of time and these are used as multiunit dosage form and drug release optimization and show efficiency level. So, Sustained release floating microspheres of Abacavir sulphate may provide a convenient dosage form for achieving best performance and release and show good bioavailability.
| Item Type: | Thesis (Masters) |
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| Additional Information: | REG.No.261510262 |
| Uncontrolled Keywords: | Formulation Design ; Development ; Invitro Evaluation ; Abacavir Sulphate ; Gastroretentive Microspheres |
| Subjects: | PHARMACY > Pharmaceutics |
| Depositing User: | Ravindran C |
| Date Deposited: | 23 Mar 2018 09:30 |
| Last Modified: | 23 Mar 2018 09:30 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/6484 |
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