ABSTRACT
Gastric retentive floating drug delivery system (GFDDS) is enabled the prolonged continuous input of the drug to the upper parts of the gastrointestinal (GI) tract and improves the bioavailability of medications with narrow absorption window. The design of the delivery system is based on the controlled release formulation with floating and swelling features in order to prolong the gastric retention time of the drug delivery systems. In the present study norfloxacin as candidate, guar gum, sodium CMC, HPMC15 KM is studied along with other excipients like PVP K30 (binder), sodium bicarbonate microcrystalline cellulose were used in different concentrations to get the desired controlled release profile over a period of 12 hrs. All the formulations were evaluated for buoyancy lag time, duration of buoyancy, dimensional stability, drug content and in vitro drug release profile. Based on the in vitro studies carried out for the optimized formulation by dissolution the performance of the developed formulation promises to be efficient in controlling the drug release rate with the guar gum , a natural polymer.
ABSTRACT
Gastric retentive floating drug delivery system (GFDDS) is enabled the prolonged continuous input of the drug to the upper parts of the gastrointestinal (GI) tract and improves the bioavailability of medications with narrow absorption window. The design of the delivery system is based on the controlled release formulation with floating and swelling features in order to prolong the gastric retention time of the drug delivery systems. In the present study norfloxacin as candidate, guar gum, sodium CMC, HPMC15 KM is studied along with other excipients like PVP K30 (binder), sodium bicarbonate microcrystalline cellulose were used in different concentrations to get the desired controlled release profile over a period of 12 hrs. All the formulations were evaluated for buoyancy lag time, duration of buoyancy, dimensional stability, drug content and in vitro drug release profile. Based on the in vitro studies carried out for the optimized formulation by dissolution the performance of the developed formulation promises to be efficient in controlling the drug release rate with the guar gum , a natural polymer.
ABSTRACT
Purpose: The objective of this study is to investigate whether the drug release profile of a multi-unit dose form consisting of fast and slow release components can be predicted from the release profiles of their components by simple summation. Method: The fast release component consisted of conventional granules of theophylline made by wet massing the drug powder with starch mucilage (20w/v). The slow release component consisted of matrix granules of the drug made by triturating the drug powder with melted carnuba wax (i.e. melt granulation). Each type of granules was compressed to tablets of weight 100; 150 or 200mg. To form the multi-unit dosage tablets of drug content 300mg each; the conventional and matrix granules were mixed in the ratio 1:2; 1:1 and 2:1; and compressed. The tablets were subjected to dissolution test and from the experimental release curve the prompt release (mp) in the first 1h; the maximum release (m ) and the time to attain it (t ) were obtained. Result: For a given composition of the multi-unit dose tablets; the theoretical release curve was obtained by summation of the release from each component at the different time intervals. The mp values of the theoretically estimated release curves were generally higher; while their t values were generally shorter than the corresponding values for the experimental curves. Conclusion: The indication is that drug release from the multi-unit dose tablets was more retarded than could be theoretically estimated. Apparently; the two components interfere with each other's release
Subject(s)
Delayed-Action Preparations , Dosage Forms , Tablets , TheophyllineABSTRACT
OBJECTIVE - Slugging is a pre-compression technique for the dry granulation of hydrolysable drugs (e.g. aspirin). The study was carried out to relate the slugging load to the hardness of the granules and the brittle fracture tendency of the final (recompressed) tablets. METHOD - Varying compression load were applied to aspirin powder to form slugs; which were subsequently broken down to form granules. These were recompressed to give the final tablets. The hardness of the slugs was determined and taken as measure of the hardness of the resulting granules. The following tableting parameters were measured for the final tablets - tensile strength (T); packing fraction (P[f]) and the brittle fracture index (BFI). RESULTS - A high slugging load was associated with the formation of hard slugs and hence hard granules. Upon recompression the hardest granules formed the hardest tablets (T = 3.29MN m**-2) while the softest granules formed the softest tablets (T=1.09MN m**-2). In turn; the hardest tablets displayed the highest brittle fracture tendency (BFI = 0.59) compared with the softest tablets (BFI= 0.21). A positive linear correlation existed between tablet hardness (T) and BFI values (r = 0.98). CONCLUSION - The study showed that excessive slugging load produces hard aspirin granules which in turn yields hard but friable tablets