Physicochemical properties, in vitro release and skin permeation studies of a topical formulation of standardized pomegranate rind extract

The aim of the present study was to develop a stable formulation containing standardized pomegranate rind extracts [SPRE] for topical use in the treatment of dermal diseases. Ellagic acid [EA] as the major active constituent of SPRE [not less than 13%] was quantified by HPLC as an indicator for studies on the stability, in vitro drug release, and skin penetration/retention. The formulation prepared with polyethylene glycols [PEG 400 and PEG 4000] containing 5% SPRE has been found to be stable and provide a release rate of 36.6741 +/- 5.0072 micro g/cm2 /h that was best fitted to the zeroorder kinetic model. EA from SPRE did not penetrate the full-thickness rat skin but the skin retention of EA was determined to be 2.22 +/- 0.16 micro g/cm2 with a total recovery of 95.14 +/- 5.51%. The results indicated that this 5% SPRE PEG ointment was of satisfactory physicochemical properties and worth further in vivo investigations

Enhanced Bromhexine Hydrochloride Solubility and Dissolution by Inclusion Complexation with Methylated β-cyclodextrin

The aim of this study was to enhance the solubility and dissolution of bromhexine hydrochloride by inclusion complexation with the cyclodextrin derivative, methylated \β-cyclodextrin (M\βCD). Inclusion complexes in 1:1 molar ratio were prepared by the kneading and coevaporation methods. The solubility of drug in methylated \β-cyclodextrin was studied. The complexes were characterized by differential scanning calorimetry (DSC), X-ray diffractometry, Fourier transform infrared (FT-IR) spectroscopy and dissolution studies. The solubility of bromhexine hydrochloride increased linearly with the concentration of methylated \β-cyclodextrin. The phase-solubility profile was classified as AL-type, indicating the formation of a 1:1 stoichiometric inclusion complex with an apparent stability constant (Ks) of 110 M⁻\¹. The crystallinity of drug from inclusion complexes was reduced. The inclusion complex prepared by the coevaporation method showed interaction between drug and methylated \β-cyclodextrin. Both kneaded and coevaporated samples gave similar dissolution profiles; of 50-, and 5-fold increases in drug dissolution were observed within the first 5 mins compared to pure drug and physical mixtures, respectively. These inclusion complexes were effective in enhancing drug dissolution, with bromhexine hydrochloride completely dissolving within 10 mins.