The Physicochemical Properties of Theophylline - Coursework Example

More water is needed to break bonds as hydrate contains hydrogen bonds between the water molecules. Anhydrous has a faster dissolution rate forming a supersaturated solution within a shorter period of time (British pharmacopoeia, 2012). Theophylline is often manufactured in modified–release formulations because of its characteristic of having a narrow therapeutic range. It is, thus, given at the right doses. Modified release formulation would provide need to be provided at every 12 hours of enough plasma concentration.

Peak serum-theophylline concentration occurs 4 hours after ingestion, which means formulation can release the drug at the right time. An overdose may be toxic. This implies that the formulation can provide a constant release of the drug. (British Pharmacopein, 2012). Talc acts as a dissolution retardant and a lubricant, Povidone (k25) acts as the binder, Hydroxyethylcellulose acts as a binder, with Nuelin SA acting as a plasticizer and as a surfactant (Raymond & Paul, 2012). Based on the spreadsheet results, it is certain that Uniphyllin 300 mg had the slowest rate of release in different media (both HCL and phosphate dissolution buffer media).

It was found out that Nueclin SA contained a higher release rate than Uniphyllin 300 in both phosphate and HCL buffer media. The per cent release of Uniphyllin 300mg in 0.1 HCL was 33.10% at 180 min. In contrast, percentage release of Neulin SA 250 mg in 0.1 HCL was 60.12 per cent at 180 min of Uniphyllin 300mg in phosphate buffer was 34.85% at 180min, while percentage release of Nuelin SA 250 in phosphate buffer was 67.12% at 180min (Raymond & Paul, 2012). From the results obtained, it is quite clear that Nuelin SA 250 displayed a PH-dependant drug release rate.

The PH dependent gradient release is due to cellulose acetate phthalate. Cellulose acetate phthalate is used as an enteric coating on capsules or tablets. They do not dissolve until they are within the stomach acidic juices of the stomach dissolving. Still, they will dissolve in the higher ph above ph 5.5 of the small intestines.