Formulation and evaluation of a buccoadhesive captopril tablets

Buccoadhesive tablets of captopril were prepared by direct compression of the drug with different polymers; Carbopol 934 [CP 934], EudragitRS 100 [EU RS 100], Chitosan [Ch], Hydroxpropyl methylcellulose [HPMC] and Polyvinylpyrrolidone K[30] [PVP K[30]] either singly or in blends of different ratios. The tablets were evaluated for their weight variation, drug content uniformity, friability, hardness, swelling index, surface pH, in-vitro bioadhesive strength and release characteristics. The bioavailability and the pharmacokinetics parameters of captopril from two selected formulations [CP 934:HPMC 6:4 andCh:HPMC 6:4] were evaluated. The in-vitro bioadhesive strength and release characteristics were found to be a function of the type of polymer and ratio of polymer blends. Swelling and bioadhesive characteristics were determined for both plain and medicated tablets. The high concentration of carbopol and chitosan containing formulations showed the greatest adhesive strength. The mean pharmacokinetic parameters of captopril after buccoadhesive tablet administration were: C[max] 506.9 ng/ml, T[max] 4 hr, AUC[0-8] 2359.5 ng.hr/mlfor CP 934: HPMC [6:4], while C[max] 429.02 ng/ml, T[max] 2.67 hr, AUC[0-8] 1637.43 ng.hr/ml for Chitosan: HPMC [6:4]. In comparison, in case of oral administration of control tablet the C[max] 591.28 ng/ml, T[max] 1.5 hr, AUC[0-8] 1869.29ng.hr/ml

Formulation and stability study of naproxen ophthalmic preparations

Naproxen was formulated in different ophthalmic preparations as drops, gels and ocuserts using cellulose derivatives such as methylcellulose, sodium carboxymethylcel-lulose and hydroxypropyl methylcellulose. All the prepared formulae [drops, gels and ocuserts] containing the drug were subjected to the study of the release characteristics. Also, the stability of naproxen ophthalmic preparations at different conditions of storage were investigated. The obtained results revealed that, the percentage released of naproxen from the three ophthalmic dosage forms after 7 hours were found to be in the following order; Drops>ocuserts>gels. These formulations exhibited the highest physical and chemical stability up to 6 months of storage at 25°C, 35°C and 45°C, except the formulae containing methylcellulose polymer, showed the least stable formulations. The drug content in the formulae containing methylcellulose was decreased about 10% after storage at different temperatures for 6 months

In-vitro evaluation of enrofloxacin ophthalmic preparation containing cyclodextrins

The effects of cyclodextrins [CyDs] [hydroxy propyl beta-cyclodextrin [HP-beta-CyD] and beta-cyclodextrin [beta-CyD]] on the solubility and release characteristics of enrofloxacin [Enr] from ophthalmic ointments and gels were investigated. The ophthalmic gels [sodium carboxymethyl cellulose [sod. CMC] and sodium alginate] and ointments [emulsion, absorption and water soluble bases] were prepared using 0.5% of the drug or equivalent amounts of its complexes with HP-beta-CyD or beta-CyD. The results revealed that the aqueous solubility of enrofloxacin was significantly increased by the formation of [1:2] inclusion complexes with CyDs. However, the solubility of enrofloxacin increased linearly as a function of HP-beta-CyD, followed by beta-CyD