ethyl-cellulose and Hypoglycemia

Due to the additional particle coalescence in the coating, changes in the dissolution profile occur over time in the formulations coated by aqueous ethylcellulose latex. Dry thermal treatment (DT) of the coating can be used as a prevention of this process. Alternatively, it is advisable to take advantage of the synergistic effect of high humidity during wet treatment (WT), which substantially accelerates the film formation. This can be a problem for time-controlled systems, which are based on the coating rupture due to the penetration of water into the core causing the increase in the system volume. This process can begin already during the WT, which may affect the coating adversely. The submitted work was focused on the stability testing of two pellet core compositions: pellets containing swelling superdisintegrant sodium carboxymethyl starch (CMS) and pellets containing osmotically active polyethylene glycol (PEG). Another objective was to identify the treatment/storage condition effects on the pellet dissolution profiles. These pellets are intended to prevent hypoglycemia for patients with diabetes mellitus and therefore, besides the excipients, pellet cores contain 75% or 80% of glucose. The pellet coating is formed by ethylcellulose-based latex, which provides the required lag time (120-360 min). The sample stability was evaluated depending on the pellet core composition (PEG, CMS) for two types of final pellet coating treatment (DT or WT). Scanning electron microscopy and Raman microspectroscopy revealed the penetration of glucose and polyethylene glycol from the core to the PEG pellet surface after WT. For the CMS sample, significant pellet swelling after WT (under the conditions of elevated humidity) was statistically confirmed by the means of stereomicroscopic data evaluation. Therefore, the acceleration of dissolution rate during the stress tests is caused by the soluble substance penetration through the coating in the case of PEG pellets or by dosage form volume increase in the case of CMS pellets. The observed mechanisms can be generally anticipated during the stability testing of the ethylcellulose coated dosage forms. The aforementioned processes do not occur after DT and the pellets are stable in the environment without increased humidity.

Topics: Cellulose; Chemistry, Pharmaceutical; Delayed-Action Preparations; Drug Compounding; Drug Implants; Drug Liberation; Drug Stability; Excipients; Glucose; Hot Temperature; Hypoglycemia; Particle Size; Polyethylene Glycols; Solubility; Starch; Surface Properties

Patients tend to evade the occurrence of hypoglycemic episodes by excessive carbohydrate intake. Glucose pellets with delayed release in the time of the maximum effect of insulin can not only prevent hypoglycemia but also eliminate the preventive carbohydrate intake. The pellets can be administered in a mixture with semisolid food. The cores containing glucose in combination with osmotically active agents (croscarmellose sodium, carmellose sodium, polyethylene glycol, or carboxymethyl starch) were prepared by extrusion-spheronization and coated with 15% water ethylcellulose dispersion (Surelease® B NF) in Wurster column (Medipo, Havlíčkův Brod, Czech Republic) into four coating levels (12.5, 25, 35, and 50%). Mean particle size is 0.63-0.73 for cores and 0.82-0.98 for coated pellets. Cores and coated pellets have excellent or good flow properties according to Hausner ratio and Carr index. Aspect ratio ranges from 1.78 to 2.17 for cores and from 1.73 to 2.31 for coated pellets. Dissolution was performed using pH-independent method and method with continual change of pH. The suitable pH-independent release was achieved in the samples containing carboxymethyl starch or polyethylene glycol. Glucose release is enabled by a membrane rupture caused by core swelling. It can be, therefore, assumed that the glucose release profile will not be affected by food or transit time.

Topics: Cellulose; Chemistry, Pharmaceutical; Child; Delayed-Action Preparations; Diabetes Mellitus; Dosage Forms; Drug Delivery Systems; Drug Implants; Excipients; Glucose; Humans; Hypoglycemia; Hypoglycemic Agents; Particle Size; Polyethylene Glycols; Solubility; Starch

Patients tend to prevent hypoglycemia by excessive saccharide intake leading to poorer glycemic control with potentially fatal consequences. This problem could be resolved by means of pellets with glucose release delayed by 120-360 min as a compensation of the antidiabetic drug peak effect. No glucose is released before; hence there is no risk of hyperglycemia and secondary complications. The pellets contain glucose in combination with an osmotically active ingredient and are coated with an ethylcellulose dispersion, which forms an insoluble semipermeable membrane and ensures delayed release. The release of glucose was assessed using dissolution and high-performance liquid chromatography. Dissolution profiles indicated the possibility of achieving the requested lag time using a combination of adequate compositions and coating concentrations. Lag times of 60, 240 and 360 min were achieved. The sample containing carboxymethyl starch was found to be most suitable for the intent of this work.

Topics: Blood Glucose; Cellulose; Chromatography, High Pressure Liquid; Delayed-Action Preparations; Drug Compounding; Excipients; Glucose; Humans; Hypoglycemia; Kinetics; Membranes, Artificial; Solubility; Starch; Surface Properties; Technology, Pharmaceutical; Water

Hypoglycemic episodes are a frequent and serious complication in both types of diabetes mellitus. The risk of hypoglycemic conditions can be managed by a coated pellet dosage form, which can release glucose in a delayed regime to achieve the maximum estimated effect of antidiabetics. The pellet cores, intended for coating with ethylcellulose, were prepared consisting of four osmotically active excipients: crosscarmellose (Ac-Di-Sol®), a mixture of microcrystalline cellulose and carmellose sodium (Avicel® RC 591), carboxymethyl starch sodium (Vivastar® P 5000) and macrogol 6000, respectively. The aim of this study was to increase the glucose content in the pellets to minimize their volume and to improve the administration to the patients. The content of glucose in the pellet cores was increased from 45 to 75 or 80%, respectively, for all compositions. All pellet samples had satisfactory mechanical and flow properties required for the coating process. The highest values of sphericity were achieved in the lower mean particle size sample containing 80% of glucose, 15% of Avicel® PH 101 and 5% of carboxymethyl starch sodium and the higher mean particle size sample containing 75% of glucose and 25% of Avicel® RC 591.

Topics: Cellulose; Chemistry, Pharmaceutical; Delayed-Action Preparations; Diabetes Mellitus; Excipients; Glucose; Humans; Hypoglycemia; Particle Size

The aim of the present investigation was to prepare glipizide matrix transdermal systems using the combinations of ethyl cellulose/polyvinylpyrrolidone and Eudragit RL-100/Eudragit RS-100. The systems were evaluated for various in vitro (drug content, drug permeation, scanning electron microscopy and drug-polymer interactions) and in vivo (acute and long-term hypoglycemic activity, biochemical and histopathological studies, skin irritation and pharmacokinetic studies in mice) parameters. Drug content of the patches was found to be more than 98%. Variations in drug permeation profiles were observed among various formulations. The scanning electron microscopy of the patches showed the formation of pores on the surface after in vitro permeation studies. The drug-polymer interaction results suggested no interaction between drug and polymers. The in vivo results revealed that the patches successfully prevented the severe hypoglycemia in the initial hours and they were also effective on chronic application. The transdermal route exhibited negligible skin irritation and produced better improvement with all the tested in vivo parameters compared to oral administration.

Topics: Acrylic Resins; Administration, Cutaneous; Animals; Cellulose; Diabetes Mellitus; Drug Delivery Systems; Glipizide; Hypoglycemia; Hypoglycemic Agents; Liver; Liver Glycogen; Mice; Mice, Inbred Strains; Microscopy, Electron, Scanning; Povidone; Skin