Drug formulations suppositories

Think about drug formulation. Is a tablet the most appropriate form of drug or would an injection, a suppository or a syrup be better Is the drug suitably packaged for the elderly patient, bearing in mind any disabilities ... 

The matrices of suppositories are not only important for drug formulation, but also vital to the local or systemic effects of drugs. 

Suppositories and pessaries— These are preparations intended for either rectal or vaginal administration of drugs. They are formulated with a suitable base that melts at body temperature. 

Massaccesi reported the development of a two-phase titration method for the analysis of miconazole and other imidazole derivatives in pure form and in pharmaceutical formulation [14], To the sample (10 mg) are added 10 mL of water, 10 mL of 1 M-sulfuric acid, 25 mL of dichloromethane and 1 mL of 0.05% indophenol blue (C.I. No. 49700) in dichloromethane solution and the solution is titrated with 10 mM sodium dodecyl sulfate until the color of the organic phase changes from blue to pale yellow. Results obtained for the drug in pure form, tablets, suppositories, cream and lotion agreed with the expected values and the coefficient of variation (n = 6) were 0.3-0.35%. Imidazole and the other constituents of the pharmaceutical preparations did not interfere. 

Since the rate of absorption of many drugs from the gastrointestinal tract is controlled by their dissolution rate, this becomes the rate-limiting step. Accurate and reliable measurements of dissolution rate are therefore required in the pharmaceutical sciences. The measurement and interpretation of the dissolution rates of solid drugs in the pure state or from formulations, such as tablets, capsules, and suppositories, has an extensive pharmaceutical literature [95-100]. Moreover, the design, operation, and interpretation of dissolution rate measurements on pharmaceutical solids have been the subject of considerable scientific study, technical development, and debate. 

To avoid the side effects of sulfapyridine, various preparations to target 5-ASA directly to sites of disease have been formulated. Also known as mesalamine, 5-ASA has been formulated in oral forms (Pentasa, Asacoi). Pentasa is a time-release capsule that releases the drug throughout the GI tract. Asacoi is a pH-dependent-release preparation that delivers drug to the distal small bowel and colon. The response of ulcerative colitis to this formulation appears to be identical to that seen with sulfasalazine. Mesalamine can also be administered as a suppository (Canasa) or enema (Rowasa) for distal colonic disease. 

The effectiveness of 5-ASA therapy depends in part on achieving high drug concentration at the site of active disease. Thus, 5-ASA suppositories or enemas are useful in patients with ulcerative colitis or Crohn s disease confined to the rectum (proctitis) or distal colon (proctosigmoiditis). In patients with ulcerative colitis or Crohn s colitis that extends to the proximal colon, both the azo compounds and mesalamine formulations are useful. For the treatment of Crohn s disease involving the small bowel, mesalamine compounds, which release 5-ASA in the small intestine, have a theoretic advantage over the azo compounds. 

Clinical use Bufexamac (Brogden et al., 1975) is a nonsteroidal anti-inflammatory drug used in topical formulations for mild skin disorders and as suppositories (250-500 mg/day) for haemorrhoids. 

The physicochemical properties of the drug molecules and the formulation can also influence rectal drug absorption (Table 7.1). Crucial parameters in this regard include drug concentration, molecular weight, solubility, lipophilicity, pKa, surface properties, and particle size [12]. In addition, formulation properties such as the nature of the suppository base material may play a critical role in regulating drug absorption. 

Miyake, M., et al. 2004. Development of suppository formulation safely improving rectal absorption of rebamipide, a poorly absorpbable drug, by utilizing sodium laurate and taurine. J Control Rel 99 63. 

Arima, H., et al. 1992. Enhanced rectal absorption and reduced local irritation of the antiinflammatory drug ethyl 4-biphenylylacetate in rats by complexation with water-soluble (3-cyclodextrin derivatives and formulation as oleaginous suppository. J Pharm Sci 81 1119. 

A vaginal suppository based on ornidazole, a drug characterized by the activity against bacteria and protozoa, demonstrated the same safety and effectiveness in the treatment of vaginitis as that of a tablet formulation in addition, the slippery and smooth surface of the suppository-facilitated application and the irritation in the vulva-vaginal region was reduced in comparison with that induced by the tablet formulation [33]. 

Hydromorphone is available through injections, tablets, oral solution, and suppositories. The usual route of administration is by way of swallowing tablets. For patients who have difficulty swallowing tablets, a flavored oral solution is available. This liquid form of the drug can be poured into a medicine dropper for measurement by the patient or a nurse. The liquid can also be added to soft foods to make it easier for the patient to ingest. Some of these liquid formulations may contain alcohol. 

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